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Glossary of terms used in health research - C

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  • Calories availability
    • The average nutritional energy content of the total daily per capita food supply, for a given country, territory, or geographic area, over a specific period in time, usually a year.
  • Capacity building
    • MeSH - Wikipedia
      Capacity building is the development of knowledge, skills, commitment, structures, systems and leadership to enable effective health promotion. It involves actions to improve health at three levels: the advancement of knowledge and skills among practitioners; the expansion of support and infrastructure for health promotion in organizations, and; the development of cohesiveness and partnerships for health in communities.
      Organizational development including enhancement of management structures, processes and procedures, within organizations and among different organizations and sectors to meet present and future needs.
  • Capital expenditure
    • MeSH - Wikipedia
      The expenditure that is required for financing permanent or semi-permanent facilities or equipment, such as buildings etc.
      Those funds disbursed for facilities and equipment, particularly those related to the delivery of health care.
  • Caregiver
    • MeSH - Wikipedia
      Carer (UK, NZ, Australian usage) and caregiver (US, Canadian usage) are words normally used to refer to unpaid relatives or friends who support people with disabilities. The words may be prefixed with "family" "spousal", "child" to distinguish between different care situations.
      Persons who provide care to those who need supervision or assistance in illness or disability. They may provide the care in the home, in a hospital, or in an institution. Although caregivers include trained medical, nursing, and other health personnel, the concept also refers to parents, spouses, or other family members, friends, members of the clergy, teachers, social workers, fellow patients, etc.
  • Carry over
    • In a cross-over trial: the persistence, into a later period of treatment, of some of the effects of a treatment applied in an earlier period.
  • Case
    • In epidemiology, a countable instance in the population or study group of a particular disease, health disorder, or condition under investigation. Sometimes, an individual with the particular disease.
  • Case-control study
    • MeSH - Wikipedia
      A type of observational analytical longitudinal retrospective study in which a group of subjects with a specified outcome (cases) and a group without that outcome (controls) are identified. Investigators then compare the extent to which each subject was previously exposed to the variable of interest, such as risk factor, a treatment, or an intervention.
      A type of observational analytic study. Enrollment into the study is based on presence ("case'') or absence ("control'') of disease. Characteristics such as previous exposure are then compared between cases and controls.
      Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
  • Case definition
    • Wikipedia
      Is a set of diagnostic criteria that must be fulfilled in order to identify a case of a particular disease. Case definitions can be based on clinical, laboratory, epidemiological, or combined clinical and laboratory criteria. When a set of criteria is standardized for purposes of identifying a particular disease, then it is referred to as "standard case definition". A surveillance case definition is one that is standardized and used to obtain an accurate detection of all cases of the targeted disease or condition in a given population, while excluding the detection of other similar conditions.
      A set of standard criteria for deciding whether a person has a particular disease or health-related condition, by specifying clinical criteria and limitations on time, place, and person.
  • Case fatality rate
    • Wikipedia
      The proportion of cases of a given disease that result in death. Often abbreviated to CFR.
      In epidemiology, case fatality (CF) or fatality rate, is the ratio of deaths within a designated population of people with a particular condition, over a certain period of time. An example of a fatality rate would be 9 deaths per 10,000 people at risk per year. This means that within a given year, out of 10,000 people formally diagnosed with a disease, 9 died.
  • Case management
    • MeSH
      A traditional term for all the activities which a physician or other health care professional normally performs to insure the coordination of the medical services required by a patient. It also, when used in connection with managed care, covers all the activities of evaluating the patient, planning treatment, referral, and follow-up so that care is continuous and comprehensive and payment for the care is obtained.
  • Case mix
    • Wikipedia
      The composition of patients treated by a hospital or another provider.
  • Case rate
    • The number of reported cases of a specific disease per 100,000 population in a given year.
  • Case report
    • Wikipedia
      A detailed report of the diagnosis, treatment, and follow-up of an individual patient. Case reports also contain some demographic information about the patient (for example, age, gender, ethnic origin).
      Case reports [MeSH - publication type]: clinical presentations that may be followed by evaluative studies that eventually lead to a diagnosis.
  • Case report form
    • Wikipedia
      A printed, optical, or electronic document designed to record all of the protocol-required information to be reported to the sponsor on each trial subject.
  • Case series
    • Wikipedia
      A group or series of case reports involving patients who were given similar treatment. Reports of case series usually contain detailed information about the individual patients. This includes demographic information (for example, age, gender, ethnic origin) and information on diagnosis, treatment, response to treatment, and follow-up after treatment.
      A study reporting observations on a series of individuals, usually all receiving the same intervention, with no control group.
  • Case study
    • Wikipedia
      A study reporting observations on a single individual. (Also called anecdote, case history, or single case report.)
      A detailed description of a concrete situation requiring ethical analysis and a resultant judgment or action. Cases provide specific circumstances involving a patient (in medical ethics), a study participant or group (in research ethics) or a population (in public health ethics). Cases are typically grouped by subject matter and as such represent the input to the methods of practical ethical reasoning.
  • Casuistry
    • MeSH - Wikipedia
      A method of practical ethical reasoning emphasizing particular cases over theories or principles. From paradigm cases and the selection of morally relevant maxims indicating the right judgment or action, the user of casuistry finds generalizable guidance for judgments and actions when confronted with similar cases. Casuistry is not incompatible with the methods of principlism and specified principlism.
      A method of ethical analysis that emphasizes practical problem solving through examining individual cases that are considered to be representative; sometimes used to denote specious argument or rationalization. Differentiate from casuistics, which is the recording and study of cases and disease.
  • Catchment area
    • MeSH - Wikipedia
      A geographic area defined and served by a health plan or a health care provider.
      A geographic area defined and served by a health program or institution.
  • Catchment population
    • Estimate of the population served by a hospital or other health service unit or facility.
  • Categorical data
    • Data that are classified into two or more non-overlapping categories. Race and type of drug (aspirin, paracetamol, etc.) are examples of categorical variables. If there is a natural order to the categories, for example, non-smokers, ex-smokers, light smokers and heavy smokers, the data are known as ordinal data. If there are only two categories, the data are dichotomous data.
  • Categorical variables
    • Data where each individual variable is one of a number of mutually exclusive classes.
  • Causal effect
    • An association between two characteristics that can be demonstrated to be due to cause and effect, i.e. a change in one causes the change in the other. Causality can be demonstrated by experimental studies such as controlled trials (for example, that an experimental intervention causes a reduction in mortality). However, causality can often not be determined from an observational study.
  • Causality
    • MeSH - Wikipedia
      The relating of causes to the effects they produce. Most of epidemiology concerns causality and several types of causes can be distinguished. It must be emphasized, however, that epidemiological evidence by itself is insufficient to establish causality, although it can provide powerful circumstantial evidence.
      Causality is the relating of causes to the effects they produce. Broadly, causality is about production in the sense that a cause is something that produces or creates an effect. Causality is fundamental to two aspects of evidence based public health: (1) demonstrating and understanding the causes of public health problems; and (2) establishing the probability and nature of causal relations between an intervention and its effects.
      The relating of causes to the effects they produce. Causes are termed necessary when they must always precede an effect and sufficient when they initiate or produce an effect. Any of several factors may be associated with the potential disease causation or outcome, including predisposing factors, enabling factors, precipitating factors, reinforcing factors, and risk factors.
  • Cause of death
    • MeSH
      Factors which produce cessation of all vital bodily functions. They can be analyzed from an epidemiologic viewpoint.
  • Cause of disease
    • A factor (characteristic, behavior, event, etc.) that directly influences the occurrence of disease. A reduction of the factor in the population should lead to a reduction in the occurrence of disease.
  • Cause-specific mortality rate
    • The mortality rate due to a specific disease (e.g. cholera) or phenomenon (e.g. violence).
      The number of deaths attributable to a specific cause per 100,000 population in a given year.
      The mortality rate from a specified cause for a population. The numerator is the number of deaths attributed to a specific cause during a specified time interval; the denominator is the size of the population at the midpoint of the time interval.
      Also called cause-specific death rate.
  • Causes of death among children aged less than 5 years
    • The causes of death are those that are entered on the medical certificate of cause of death in countries and recorded by the civil (vital) registration systems. For the analyses, we have used the concept of the 'underlying cause of death' as defined by ICD (WHO, 1992). In countries with incomplete or no civil registration, causes of death are those reported as such in epidemiological studies that use verbal autopsy algorithms to establish cause of death.
  • Censored
    • In survival analysis: a term used in studies where the outcome is the time to a particular event, to describe data from patients where the outcome is unknown. A patient might be known not to have had the event only up to a particular point in time, so ‘survival time’ is censored at this point.
  • Census
    • MeSH Wikipedia
      A census is the procedure of systematically acquiring and recording information about the members of a given population.
      A canvass of a given area, resulting in an enumeration of the entire population and often the compilation of other demographic, social, and economic information pertaining to that population at a specific time.
      The enumeration of an entire population, usually with details being recorded on residence, age, sex, occupation, ethnic group, marital status, birth history, and relationship to head of household.
      Enumerations of populations usually recording identities of all persons in every place of residence with age or date of birth, sex, occupation, national origin, language, marital status, income, relation to head of household, information on the dwelling place, education, literacy, health-related data (e.g., permanent disability), etc. The census or "numbering of the people" is mentioned several times in the Old Testament. Among the Romans, censuses were intimately connected with the enumeration of troops before and after battle and probably a military necessity.
  • Central tendency
    • Wikipedia
      The average (mean), middle (median) or most common (mode) score for numerical data in a frequency distribution.
  • Certification
    • MeSH
      Compliance with a set of standards defined by non-governmental organizations. Certification is applied for by individuals on a voluntary basis and represents a professional status when achieved, e.g., certification for a medical specialty.
  • Channeling bias
    • Tendency of clinicians to prescribe treatment based on a patient’s prognosis. As a result of the behavior, in observational studies, treated patients are more or less likely to be high-risk patients than untreated patients, leading to biased estimate of treatment effect.
  • Checklist
    • MeSH - Wikipedia
      A type of informational job aid used to reduce failure by compensating for potential limits of human memory and attention.
      Aid for consistent recording of data such as tasks completed and observations noted.
  • Checklist effect
    • The effect on clinicians’ behavior of having them record information, or their orders, using a structured data collection form.
      The improvement seen in medical decision making because of more complete and structured data collection (e.g., clinicians fill out a detailed form, so their decisions improve).
  • Chi-square distribution
    • MeSH - Wikipedia
      A statistical test used for categorical data. It is based on a comparison of the frequencies observed and the frequencies expected in the various categories.
      A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.
  • Child
    • MeSH
      A person 6 to 12 years of age. An individual 2 to 5 years old is child, preschool.
  • Child health services
    • MeSH
      Organized services to provide health care for children.
  • Child mortality
    • MeSH
      Number of deaths of children between one year of age to 12 years of age in a given population.
  • Child mortality rate
    • Wikipedia
      The probability of a child born in a specific year or period dying before reaching the age of five, if subject to age-specific mortality rates of that period. Under-five mortality rate as defined here is strictly speaking not a rate (i.e. the number of deaths divided by the number of population at risk during a certain period of time) but a probability of death derived from a life table and expressed as rate per 1,000 live births.
      The child mortality rate or under-5 mortality rate is the number of children who die by the age of five, per thousand live births.
      The number of children under five years of age dying per 1,000 live births in a given year.
      Also called under-five mortality rate.
  • Child-woman ratio
    • The number of children under age 5 per 1,000 women ages 15-44 or 15-49 in a population in a given year. This crude fertility measure, based on basic census data, is sometimes used when more specific fertility information is not available.
  • Childbearing years
    • The reproductive age span of women, assumed for statistical purposes to be 15-44 or 15-49 years of age.
  • Childbirth
    • MeSH
      The process of giving birth to one or more offspring.
      Also called birth, parturition.
  • Childlessness
    • Childlessness (demographic studies): inability to bear any children, either due to the inability to conceive or the inability to carry a pregnancy to a live birth. Childlessness at the end of the reproductive years is most effectively studied by using women in the oldest age cohort: women 45 to 49 years.
      Percentage of women who are currently married, have been so for at least five years, and who have no living children.
  • Children aged <5 years overweight
    • Percentage of overweight (weight-for-height above +2 standard deviations of the WHO Child Growth Standards median) among children aged 0-5 years.
  • Children aged <5 years stunted
    • Percentage of stunting (height-for-age less than -2 standard deviations of the WHO Child Growth Standards median) among children aged 0-5 years.
  • Children aged <5 years underweight
    • Percentage of underweight (weight-for-age less than -2 standard deviations of the WHO Child Growth Standards median) among children aged 0-5 years.
  • Chronology
    • MeSH - Wikipedia
      The temporal sequence of events that have occurred.
      Chronology [MeSH - publication type]: works consisting of lists of events arranged in chronological order.
  • Civil defense
    • MeSH - Wikipedia
      Civil defense or civil protection is an effort to prepare non-combatants for military attack.
      Preventive emergency measures and programs designed to protect the individual or community in times of hostile attack.
  • Class interval
    • A span of values of a continuous variable which are grouped into a single category for a frequency distribution of that variable.
  • Classical article
    • Classical article [MeSH - publication type]: works consisting of a current presentation of a previously printed seminal article marking a milestone in the history of medicine or science. It is usually accompanied by introductory remarks heralding its reprinting, often on the anniversary of its original publication or on an anniversary of the author's birth or death. It is usually reprinted in full, with complete bibliographical reference to the original appearance.
  • Clinical
    • Wikipedia
      Pertaining to or founded on observation and treatment of participants, as distinguished from theoretical or basic science.
  • Clinical audit
    • MeSH - Wikipedia
      A cyclical evaluation and measurement by health professionals of the clinical standards they are achieving.
      A detailed review and evaluation of selected clinical records by qualified professional personnel to improve the quality of patient care and outcomes. The clinical audit was formally introduced in 1993 into the United Kingdom's National Health Service.
  • Clinical coder
    • Wikipedia
      A clinical coder, also known as diagnostic coder or medical coder, is a health care professional whose main duties are to analyse clinical statements and assign codes from a clinical classification.
  • Clinical conference
    • Clinical conference [MeSH: publication type]: work that consists of a conference of physicians on their observations of a patient at the bedside, regarding the physical state, laboratory and other diagnostic findings, clinical manifestations, results of current therapy, etc. A clinical conference usually ends with a confirmation or correction of clinical findings by a pathological diagnosis performed by a pathologist. "Clinical conference" is often referred to as a "clinico-pathological conference."
  • Clinical data acquisition
    • Wikipedia
      Acquisition or collection of clinical trial data can be achieved through various methods that may include, but are not limited to, any of the following: paper or electronic medical records, paper forms completed at a site, interactive voice response systems, local electronic data capture systems, or central web based systems.
  • Clinical decision support system
    • MeSH - Wikipedia
      Clinical decision support systems (CDSS or CDS) are interactive computer programs, which are designed to assist physicians and other health professionals with decision making tasks. Clinical decision support systems link health observations with health knowledge to influence health choices by clinicians for improved health care.
      A strategy for changing clinician behavior. An information system used to integrate clinical and patient information and provide support for decision-making in patient care.
      Computer-based information systems used to integrate clinical and patient information and provide support for decision-making in patient care.
  • Clinical effectiveness
    • The extent to which a specific intervention, procedure, regimen or service does what it is intended to do under ordinary circumstances rather than controlled conditions. Or, more specifically, the evaluation of benefit to risk of an intervention, in a standard clinical setting, using outcomes measuring issues of importance to patients (e.g. ability to do daily activities, longer life, etc.).
  • Clinical ethics
    • MeSH
      The identification, analysis, and resolution of moral problems that arise in the care of patients.
  • Clinical ethics committees
    • MeSH
      Hospital or other institutional ethics committees established to consider the ethical dimensions of patient care. Distinguish from ethics committees, research, which are established to monitor the welfare of patients or healthy volunteers participating in research studies.
  • Clinical gestalt
    • The physician's overall intuitive sense of the likelihood of disease established after the clinical evaluation of the patient. The clinical evaluation may include risk factors, history, symptoms, signs, and basic laboratory or radiological studies.
  • Clinical governance
    • MeSH - Wikipedia
      Clinical governance is the term used to describe a systematic approach to maintaining and improving the quality of patient care within a health system.
      A framework through which the United Kingdom's National Health Service organizations are accountable for continually improving the quality of their services and safeguarding high standards of care by creating an environment in which excellence in clinical care will flourish.
  • Clinical guideline
    • Wikipedia
      A systematically developed statement for practitioners and participants about appropriate health care for specific clinical circumstances.
  • Clinical investigation
    • Any experiment that involves a test article and one or more human subjects.
  • Clinical investigator
    • Wikipedia
      A medical researcher in charge of carrying out a clinical trial's protocol.
  • Clinical medicine
    • MeSH
      The study and practice of medicine by direct examination of the patient.
  • Clinical monitoring
    • Wikipedia
      Oversight and administrative efforts that monitor a participant's health during a clinical trial.
  • Clinical nursing research
    • MeSH
      Research carried out by nurses in the clinical setting and designed to provide information that will help improve patient care. Other professional staff may also participate in the research.
  • Clinical outcome
    • Measures patient health or well being. Ideally it should be credible, comprehensive, sensitive to change, accurate, sensible, and biologically sensible.
  • Clinical pathway
    • MeSH Wikipedia
      Clinical pathways, also known as care pathways, critical pathways, integrated care pathways, or care maps, are one of the main tools used to manage the quality in healthcare concerning the standardization of care processes.
      Multidisciplinary management tool based on evidence-based practice for a specific group of patients with a predictable clinical course, in which the different tasks (interventions) by the professionals involved in the patient care are defined, optimized and sequenced either by hour (ED), day (acute care) or visit (homecare). Outcomes are tied to specific interventions.
      Schedules of medical and nursing procedures, including diagnostic tests, medications, and consultations designed to effect an efficient, coordinated program of treatment.
  • Clinical practice guideline
    • Wikipedia
      Guideline developed to help health care professionals and patients make decisions about screening, prevention, or treatment of a specific health condition.
      A strategy for changing clinician behavior. Systematically developed statements or recommendations to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances. They present indications for performing a test, procedure, or intervention, or the proper management for specific clinical problems. Guidelines may be developed by government agencies, institutions, organizations such as professional societies or governing boards, or by convening expert panels.
      A systematically developed statement to assist practitioner and patient decisions about appropriate health care for one or more specific clinical circumstances. The development of clinical practice guidelines can be considered to be a particular type of health technology assessment (HTA) or it can be considered to be one of the types of policy-making that is informed or supported by HTA.
  • Clinical prediction rule
    • Wikipedia
      A clinical prediction rule is type of medical research study in which researchers try to identify the best combination of medical sign, symptoms, and other findings in predicting the probability of a specific disease or outcome.
      A guide for practice that is generated by initially examining, and ultimately combining, a number of variables to predict the likelihood of a current diagnosis or a future event. Sometimes, if the likelihood is sufficiently high or low, the rule generates a suggested course of action.
  • Clinical pregnancy
    • A pregnancy diagnosed by ultrasonographic visualization of one or more gestational sacs or definitive clinical signs of pregnancy. It includes ectopic pregnancy. Note: multiple gestational sacs are counted as one clinical pregnancy.
  • Clinical pregnancy rate
    • The number of clinical pregnancies expressed per 100 initiated cycles, aspiration cycles or embryo transfer cycles. Note: when clinical pregnancy rates are given, the denominator (initiated, aspirated or embryo transfer cycles) must be specified.
  • Clinical pregnancy with fetal heart beat
    • Pregnancy diagnosed by ultrasonographic or clinical documentation of at least one fetus with heart beat. It includes ectopic pregnancy.
  • Clinical protocol
    • MeSH
      Precise and detailed plan for the study of a medical or biomedical problem and/or plan for a regimen of therapy.
  • Clinical quality improvement
    • An interdisciplinary process designed to improve the delivery of preventive, diagnostic, therapeutic, and rehabilitative measures in order to maintain, restore, and improve health outcomes of individuals and populations cost-effectively.
  • Clinical research
    • MeSH - Wikipedia
      Clinical research is a branch of medical science that determines the safety and effectiveness of medications, devices, diagnostic products and treatment regimens intended for human use. These may be used for prevention, treatment, diagnosis or for relieving symptoms of a disease.
  • Clinical researcher
    • Wikipedia
      A health professional who works directly with patients, or uses data from patients, to do research on health and disease and to develop new treatments. Clinical researchers may also do research on how health care practices affect health and disease.
  • Clinical series
    • Wikipedia
      A case series in which the patients receive treatment in a clinic or other medical facility.
  • Clinical surveillance
    • Wikipedia
      Clinical surveillance (or syndromic surveillance) refers to the surveillance (systematic collection, analysis, and interpretation) of health data about a clinical syndrome that has a significant impact on public health, which is then used to drive decisions about health policy and health education.
  • Clinical trial
    • MeSH - Wikipedia
      An experiment to compare the effects of two or more healthcare interventions. Clinical trial is an umbrella term for a variety of designs of healthcare trials, including uncontrolled trials, controlled trials, and randomized controlled trials. (Also called intervention study.)
      Pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects.
      Clinical trial [MeSH - publication type]: work that is the report of a pre-planned clinical study of the safety, efficacy, or optimum dosage schedule of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques in humans selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. While most clinical trials concern humans, this publication type may be used for clinical veterinary articles meeting the requisites for humans.
  • Clinical trial management system
    • Wikipedia
      A clinical trial management system, also known as CTMS, is a customizeable software system used by the biotechnology and pharmaceutical industries to manage the large amounts of data involved with the operation of a clinical trial.
  • Clinical trial protocol
    • Wikipedia
      A clinical trial protocol is a document that describes the objective(s), design, methodology, statistical considerations, and organization of a clinical trial. The protocol usually also gives the background and reason the trial is being conducted, but these could be provided in other documents referenced in the protocol (such as an investigator's brochure).
  • Clinical trial/study report
    • A written description of a trial/study of any therapeutic, prophylactic, or diagnostic agent conducted in human subjects, in which the clinical and statistical description, presentations, and analyses are fully integrated into a single report.
      The report of a pre-planned clinical study of the safety, efficacy, or optimum dosage schedule of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques in humans selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. While most clinical trials concern humans, this publication type may be used for clinical veterinary articles meeting the requisites for humans.
  • Clinically significant
    • Wikipedia
      A result (e.g. a treatment effect) that is large enough to be of practical importance to patients and healthcare providers. This is not the same thing as statistically significant. Assessing clinical significance takes into account factors such as the size of a treatment effect, the severity of the condition being treated, the side effects of the treatment, and the cost. For instance, if the estimated effect of a treatment for acne was small but statistically significant, but the treatment was very expensive, and caused many of the treated patients to feel nauseous, this would not be a clinically significant result. Showing that a drug lowered the heart rate by an average of 1 beat per minute would also not be clinically significant.
  • Clinician
    • Wikipedia
      A health professional who takes care of patients.
  • Closed population
    • A population with no migratory flow either in or out, so that changes in population size occur only through births and deaths.
  • Clouded thinking
    • A form of innumeracy, in which a person knows about the risks but not how to draw conclusions or inferences from them. For instance, physicians often know the error rates of mammography and the base rate of breast cancer, but not how to infer from this information the chances that a woman with a positive test actually has breast cancer. Mind tools for overcoming clouded thinking, such as natural frequencies, are representations that facilitate drawing conclusions.
  • Cluster
    • Wikipedia
      An aggregation of cases of a disease or other health-related condition, particularly cancer and birth defects, which are closely grouped in time and place. The number of cases may or may not exceed the expected number; frequently the expected number is not known.
      Refers to a grouping of health-related events that are related temporally and in proximity.
  • Cluster analysis
    • MeSH - Wikipedia
      A statistical procedure in which the unit of analysis matches the unit of randomization, which is something other than the patient or participant (e.g., school, clinic).
      A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.
  • Cluster assignment
    • The assignment of groups (e.g., schools, clinics) rather than individuals to intervention and control groups. This approach is often used when assignment by individuals is likely to result in contamination (e.g., if adolescents within a school are assigned to receive or not receive a new sex education program, it is likely that they will share the information they learn with one another; instead, if the unit of assignment is schools, entire schools are assigned to receive or not receive the new sex education program). Cluster assignment is typically randomized, but it is possible (though not advisable) to assign clusters to treatment or control by other methods.
  • Cluster randomized trial
    • Wikipedia
      A trial in which clusters of individuals (e.g. clinics, families, geographical areas), rather than individuals themselves, are randomized to different arms. In such studies, care should be taken to avoid unit of analysis errors.
  • Cluster sampling
    • Wikipedia
      A type of random sampling, based first on the random selection of certain subgroups, from which the sample can be taken.
      A cluster sample is one in which the whole population being studied is divided into clusters or groups, and a selection of these clusters is then made, and the entire population or a random sample of subjects within these sub-clusters are sampled. (e.g. if the sampling frame was an entire city, then the city would be broken down into city blocks and certain randomly selected city blocks would be sampled instead of the entire city).
      A sampling design commonly used in retrospective mortality surveys when comprehensive lists of individual households cannot be obtained. Clusters are groups of households of which the first is chosen at random, and the remainder by a rule of proximity (e.g. second closest). In a cluster mortality survey, 30 or more clusters are usually sampled from the target study population, and each cluster usually contains at least 30 households.
  • Codes of ethics
    • MeSH
      Systematic statements of principles or rules of appropriate professional conduct, usually established by professional societies.
  • Coding
    • A method of analysis of qualitative data obtained for example in interviews, where categories are labeled to facilitate computer analysis and examination of relationships.
  • Coercion
    • MeSH - Wikipedia
      Manipulation, excessive pressure or influence to force or entice a person to enroll in a research project or a public health program (for example, screening, immunization). May take the form of excessive incentives, social pressure, use of authority figures, or playing upon perceived vulnerability of the person.
      The use of force or intimidation to obtain compliance.
  • Cohort
    • Wikipedia
      A group of individuals who share a common trait, such as birth year. In medicine, a cohort is a group that is part of a clinical trial or study and is observed over a period of time.
      In epidemiology, a group of individuals with some characteristics in common.
      A well-defined group of people who have had a common experience or exposure, who are then followed up for the incidence of new diseases or events, as in a cohort or prospective study. A group of people born during a particular period or year is called a birth cohort.
  • Cohort analysis
    • Observation of a cohort's demographic behavior through life or through many periods; for example, examining the fertility behavior of the cohort of people born between 1940 and 1945 through their entire childbearing years. Rates derived from such cohort analyses are cohort measures.
  • Cohort effect
    • MeSH
      Variation in health status arising from different causal factors to which each birth cohort in a population is exposed as environment and society change.
  • Cohort study
    • MeSH - Wikipedia
      A research study that compares a particular outcome in groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke compared with those who do not smoke).
      The term used in clinical and epidemiological research to describe a longitudinal prospective observational study.
      A type of observational analytic study. Enrollment into the study is based on exposure characteristics or membership in a group. Disease, death, or other health-related outcomes are then ascertained and compared.
      Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
  • Co-intervention
    • The application of additional diagnostic or therapeutic procedures to people receiving a particular programmed of treatment. In a controlled trial, members of either or both the experimental and the control groups might receive co-interventions.
  • Coitus
    • MeSH - Wikipedia
      Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which the male reproductive organ enters the female reproductive tract.
      The sexual union of a male and a female, a term used for human only.
  • Collaborative trialists’ group
    • Investigators who conduct similar randomized controlled trials and agree to contribute individual patient data from their trials to a meta-analysis.
  • Collected works
    • Collected works [MeSH - publication type]: works consisting of collections of previously published works.
  • Comment
    • Comment [MeSH - publication type]: work consisting of a critical or explanatory note written to discuss, support, or dispute an article or other presentation previously published. It may take the form of an article, letter, editorial, etc. It appears in publications under a variety of names: comment, commentary, editorial comment, viewpoint, etc.
  • Commissioning
    • The process by which the health needs of the population are defined, priorities determined and appropriate services purchased and evaluated.
  • Communitarian ethics
    • An approach to ethics emphasizing communal values, the common good, social goals, and traditional practices. Closely aligned with the cooperative virtues and a community's shared understanding of the good life. Often pitted against liberal individualism (that is, rights-based approaches) in its militant forms, a moderate communitarian view makes room for individual rights.
  • Community
    • Wikipedia
      A unit, generally geographically defined, which is the locus of basic political and social responsibility and in which everyday social interactions involving all or most of the spectrum of life activities of the people within it takes place.
  • Community-based clinical trial
    • Wikipedia
      A clinical trial conducted primarily through primary-care physicians rather than academic research facilities.
  • Community-based participatory research
    • MeSH - Wikipedia
    • Research conducted with the collaboration of a community for the purpose of taking action or effecting change. The community, in this case, could be any geographically, socioculturally, or occupationally defined group with common interests and goals. In both participatory research and community-based participatory research, the research questions generally emerge as a result of the attempt to move forward toward a set of objectives, not as the a priori reason for the research.
      Collaborative process of research involving researchers and community representatives.
  • Community-based research
    • Research that is conducted in community settings and is intended to improve community-based interventions and community health.
  • Community effectiveness
    • The ability of a particular medical action to alter the national history of a particular disease for the better, under actual conditions of practice and use.
  • Community health aides
    • MeSH
      Persons trained to assist professional health personnel in communicating with residents in the community concerning needs and availability of health services.
  • Community health nursing
    • MeSH
      General and comprehensive nursing practice directed to individuals, families, or groups as it relates to and contributes to the health of a population. This is not an official program of a Public Health Department.
  • Community health planning
    • MeSH
      Planning that has the goals of improving health, improving accessibility to health services, and promoting efficiency in the provision of services and resources on a comprehensive basis for a whole community.
  • Community health services
    • MeSH
      Diagnostic, therapeutic and preventive health services provided for individuals in the community.
  • Community health worker
    • Wikipedia
      Community health workers (CHW), sometimes called "village health workers" are members of a community who are chosen by community members to provide basic health and medical care to their community. Other names for community health workers are village health workers (VHW), health workers and lay health advisors.
      WHO Statistical Information System: includes traditional medicine practitioners, faith healers, assistant/community health-education workers, community health officers, family health workers, lady health visitors, health extension package workers, community midwives, institution-based personal care workers and traditional birth attendants.
  • Community medicine
    • MeSH
      A branch of medicine concerned with the total health of the individual within the home environment and in the community, and with the application of comprehensive care to the prevention and treatment of illness in the entire community.
  • Community programs
    • Activities carried out at community level stimulating the involvement of community actors/institutions (for example: school, youth centre, neighborhood, city, city districts) in order to intervene in people's immediate surroundings and to facilitate active participation in a social context.
  • Comorbidity
    • MeSH - Wikipedia
      The presence of one or more diseases or conditions other than those of primary interest. In a study looking at treatment for one disease or condition, some of the individuals may have other diseases or conditions that could affect their outcomes. (A co-morbidity may be a confounder.)
      The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.
  • Comparative effectiveness research
    • MeSH - Wikipedia
      Direct comparison of existing health care interventions to determine which work best for which patients and which pose the greatest benefits and harms.
      Conduct and synthesis of systematic research comparing interventions and strategies to prevent, diagnose, treat, and monitor health conditions. The purpose of this research is to inform patients, providers, and decision-makers, responding to their expressed needs, about which interventions are most effective for which patients under specific circumstances.
  • Comparative study
    • Comparative study [MeSH - publication type]: comparison of outcomes, results, responses, etc for different techniques, therapeutic approaches or other inputs.
  • Comparator
    • Wikipedia
      An investigational or marketed product (i.e., active control), or placebo, used as a reference in a clinical trial.
  • Comparison groups
    • The groups being compared in the randomized trial. Also referred to as "study groups", "treatment groups", "the arms" of a trial, or by individual terms such as treatment and control groups.
  • Compassionate use
    • Wikipedia
      A method of providing experimental therapeutics prior to final FDA approval for use in humans. This procedure is used with very sick individuals who have no other treatment options. Often, case-by-case approval must be obtained from the FDA for "compassionate use" of a drug or therapy.
  • Compassionate use trial
    • MeSH - Wikipedia
      A way to provide an investigational therapy to a patient who is not eligible to receive that therapy in a clinical trial, but who has a serious or life-threatening illness for which other treatments are not available. Compassionate use trials allow patients to receive promising but not yet fully studied or approved therapies when no other treatment option exists. Also called expanded access trial.
  • Complete follow-up
    • The investigators are aware of the outcome in every patient who participated in a study.
  • Completed fertility rate
    • The number of children born per woman to a cohort of women by the end of their childbearing years.
  • Completeness
    • Wikipedia
      Completeness considers whether the research evidence provides all the information that is required. For example, when evaluating evidence on public health interventions, reviewers need descriptive information on the intervention strategies that were adopted; the implementation of the intervention and how well it was done; the setting and circumstances in which it was implemented; whom the intervention reached (or did not reach); and how the intervention was received. Reviewers should also seek information on the unanticipated intervention effects, effect modification, and the potential harms of intervention.
  • Completeness of reporting
    • Proportion of surveillance reports (or forms) received irrespective of when the reports were submitted. Proportion of reports received based on expected reporting units (if the system includes zero reporting).
  • Completer analysis
    • Analysis of data from only those participants who remained at the end of the study.
  • Compliance
    • MeSH - Wikipedia
      Compliance (or adherence, or concordance) is a medical term that means the degree to which a patient correctly follows medical advice.
      Adherence to all the trial-related requirements, good clinical practice (GCP) requirements, and the applicable regulatory requirements.
      Voluntary cooperation of the patient in following a prescribed regimen.
      Also called patient compliance, patient adherence.
  • Composite endpoint
    • When investigators measure the effect of treatment on an aggregate of endpoints of various importance. Inferences from composite endpoints are strongest in the rare situations in which (1) the component endpoints are of similar patient-importance, (2) the endpoints that are more important occur with at least similar frequency to those that are less important, and (3) strong biologic rationale supports results that, across component endpoints, show similar relative risks with sufficiently narrow confidence intervals.
  • Computer-assisted decision making
    • MeSH
      Use of an interactive computer system designed to assist the physician or other health professional in choosing between certain relationships or variables for the purpose of making a diagnostic or therapeutic decision.
  • Computer decision support system
    • Wikipedia
      A strategy for changing clinician behavior. Computer-based information systems used to integrate clinical and patient information and provide support for decision making in patient care. In clinical decision support systems (CDSSs) that are computer based, detailed individual patient data are entered into a computer program and are sorted and matched to programs or algorithms in a computerized database, resulting in the generation of patient-specific assessments or recommendations. CDSSs can have the following purposes: alerting, reminding, critiquing, interpreting, predicting, diagnosing, and suggesting.
  • Concealment
    • Randomization is concealed if the person who is making the decision about enrolling a patient is unaware of whether the next patient enrolled will be entered in the intervention or control group (using techniques such as central randomization or sequentially numbered opaque, sealed envelopes). If randomization is not concealed, patients with better prognoses may tend to be preferentially enrolled in the active intervention arm, resulting in exaggeration of the apparent benefit of intervention (or even falsely concluding that the intervention is efficacious).
  • Conditional probability
    • Wikipedia
      The probability that an event A occurs given event B, usually written p(A|B). An example of a conditional probability is the probability of a positive screening mammogram given breast cancer, which is around 0.9.
  • Condom use at higher risk sex among young people aged 15-24 years
    • Percentage of young people aged 15-24 years reporting the use of a condom during the last sexual intercourse with a non-regular partner among those who had sex with a non-regular partner in the last 12 months.
  • Condom use during higher-risk sex
    • Percentage of women and men aged 15–49 who have had more than one sexual partner in the past 12 months who report the use of a condom during their last sexual intercourse.
  • Confidence interval
    • MeSH - Wikipedia
      A measure of the uncertainty around the main finding of a statistical analysis. Estimates of unknown quantities, such as the odds ratio comparing an experimental intervention with a control, are usually presented as a point estimate and a 95% confidence interval. This means that if someone were to keep repeating a study in other samples from the same population, 95% of the confidence intervals from those studies would contain the true value of the unknown quantity. Alternatives to 95%, such as 90% and 99% confidence intervals, are sometimes used. Wider intervals indicate lower precision; narrow intervals, greater precision. (Also called CI.)
      A range of values for a variable of interest, e.g., a rate, constructed so that this range has a specified probability of including the true value of the variable.
  • Confidence limits
    • Wikipedia
      The upper and lower boundaries of a confidence interval.
  • Confidentiality
    • MeSH - Wikipedia
      Refers to information, often of a private or sensitive nature, which a person has chosen to reveal but which is protected from being revealed to others. Confidential information should not be shared with anyone without consent except when there is a clear ethical justification (for example, approval by a human subjects research review panel), or a legal requirement (for example, regulations to protect children). Research use of identifiable data without consent requires showing importance of the research, minimal risk to those whose information is used, promise of benefit to society, and an obligation to maintain the confidentiality of the information.
      The privacy of information and its protection against unauthorized disclosure.
  • Confidentiality regarding trial participants
    • Wikipedia
      Refers to maintaining the confidentiality of trial participants including their personal identity and all personal medical information. The trial participants' consent to the use of records for data verification purposes should be obtained prior to the trial and assurance must be given that confidentiality will be maintained.
      Prevention of disclosure, to other than authorized individuals, of a sponsor's proprietary information or of a subject's identity.
  • Conflict of interest
    • MeSH
      A statement by a contributor to a report or review of personal, financial, or other interests that could have influenced someone.
      A situation in which the private interests of someone involved in the assessment or evaluation process (e.g. interviewer, rater, scorer, evaluator) have an impact (either positive or negative) on the quality of the evaluation activities, the accuracy of the data or the results of the evaluation.
      Conflict of interest relates to the fact that sponsoring from industry has been associated with restricted or selective publication of data. Thus, such studies may introduce bias if industry-sponsored studies tend to more often report positive results (which they actually do) and withhold data from studies showing no or harmful effects. Thus, studies may introduce the bias of overestimating the effectiveness of the technology.
      A situation in which an individual might benefit personally from official or professional actions. It includes a conflict between a person's private interests and official responsibilities in a position of trust. The term is not restricted to government officials. The concept refers both to actual conflict of interest and the appearance or perception of conflict.
  • Confounded comparison
    • A comparison between two treatment groups that will give a biased estimate of the effect of treatment due to the study design. For a comparison to be unconfounded, the two treatment groups must be treated identically apart from the randomized treatment. For instance, to estimate the effect of heparin in acute stroke, a trial of heparin alone versus placebo would provide an unconfounded comparison. However, a trial of heparin alone versus aspirin alone provides a confounded comparison of the effect of heparin.
  • Confounding variable
    • MeSH Wikipedia
      In statistics, a confounding variable (also confounding factor, lurking variable, a confound, or confounder) is an extraneous variable in a statistical model that correlates (positively or negatively) with both the dependent variable and the independent variable.
      A characteristic that may be distributed differently between the study and control groups and that can effect the outcome being assessed.  Confounding may be due to chance or bias.
      A factor that is associated with both an intervention (or exposure) and the outcome of interest. For example, if people in the experimental group of a controlled trial are younger than those in the control group, it will be difficult to decide whether a lower risk of death in one group is due to the intervention or the difference in ages. Age is then said to be a confounder, or a confounding variable. Randomization is used to minimize imbalances in confounding variables between experimental and control groups. Confounding is a major concern in non-randomized studies.
      Factors that can cause or prevent the outcome of interest, are not intermediate variables, and are not associated with the factor(s) under investigation. They give rise to situations in which the effects of two processes are not separated, or the contribution of causal factors cannot be separated, or the measure of the effect of exposure or risk is distorted because of its association with other factors influencing the outcome of the study.
  • Congresses
    • MeSH
      Conferences, conventions or formal meetings usually attended by delegates representing a special field of interest.
      Congresses [MeSH - publication type]: published records of the papers delivered at or issued on the occasion of individual congresses, symposia, and meetings; abstracts of papers delivered at such congresses; reports of the officers and delegates of such congresses; combinations of the foregoing; or proceedings of the conference of a society if they are not limited to matters of internal organization.
  • Conjoint analysis
    • Wikipedia
      A method of “estimating the relative importance of different aspects of (health) care, the trade-offs between these aspects, and the total satisfaction or utility that respondents derive from health care services”. The most common method entails asking respondents to choose between a series of paired descriptions of alternative service configurations, from which the importance of the different attributes of each service can be estimated. The technique is now referred to as discrete choice experimentation.
  • Consecutive case series
    • Wikipedia
      A clinical study that includes all eligible patients identified by the researchers during the study registration period. The patients are treated in the order in which they are identified. This type of study usually does not have a control group.
  • Consecutive sample
    • A sample in which all potentially eligible patients seen over a period of time are enrolled.
  • Consecutive sampling
    • A sampling procedure in which subjects are selected by taking every individual that presents over a specified period of time.
  • Consensus
    • MeSH
      General agreement or collective opinion; the judgment arrived at by most of those concerned.
  • Consensus building
    • The process by which a group reaches agreement about the best solution to a problem or the best choice among alternative options.
  • Consensus development conference
    • MeSH
      Presentations of summary statements representing the majority agreement of physicians, scientists, and other professionals convening for the purpose of reaching a consensus--often with findings and recommendations--on a subject of interest. The Conference, consisting of participants representing the scientific and lay viewpoints, is a significant means of evaluating current medical thought and reflects the latest advances in research for the respective field being addressed.
      Consensus development conference [MeSH - publication type]: a work that consists of summary statements representing the majority and current agreement of physicians, scientists, and other professionals meeting to reach a consensus on a selected subject.
  • Consistency
    • If two sections in clinical evidence address the same question then we attempt to avoid repetition of the evidence, but aim instead to provide a cross reference.
      Consistency means the results are replicated in studies in different settings or using different methods and thus the measured association is consistent.
  • Construct validity
    • Wikipedia
      A construct is a theoretically derived notion of the domain(s) we wish to measure. An understanding of the construct will lead to expectations about how an instrument should behave if it is valid. Construct validity therefore involves comparisons between measures and examination of the logical relationships, which should exist between a measure and characteristics of patients and patient groups.
  • Consumer health information
    • MeSH
      Information intended for potential users of medical and healthcare services. There is an emphasis on self-care and preventive approaches as well as information for community-wide dissemination and use.
  • Consumer participation
    • MeSH
      Community or individual involvement in the decision-making process.
  • Consumer satisfaction
    • MeSH
      A measurement that obtains reports or ratings from consumers about services received from an organization; in this context, this often means from a hospital, physician or health care provider.
      Customer satisfaction or dissatisfaction with a benefit or service received.
  • Contact tracing
    • MeSH - Wikipedia
      In epidemiology, contact tracing is the identification and diagnosis of persons who may have come into contact with an infected person.
      Identification of those persons (or animals) who have had such an association with an infected person, animal, or contaminated environment as to have had the opportunity to acquire the infection. Contact tracing is a generally accepted method for the control of sexually transmitted diseases.
  • Contamination
    • In a controlled trial: the inadvertent application of the intervention being evaluated to people in the control group; or inadvertent failure to apply the intervention to people assigned to the intervention group. Fear of contamination is one motivation for performing a cluster randomized trial.
  • Content validity
    • Wikipedia
      The extent to which a variable (e.g. a rating scale) measures what it is supposed to measure.
  • Context
    • The conditions and circumstances that are relevant to the application of an intervention, for example the setting (in hospital, at home, in the air); the time (working day, holiday, night-time); type of practice (primary, secondary, tertiary care; private practice, insurance practice, charity); whether routine or emergency.
  • Contingency planning
    • Wikipedia
      The process of establishing program objectives, approaches and procedures to respond to situations or events that are likely to occur, including identifying those events and developing likely scenarios and appropriate plans to prepare and respond to them in an effective manner.
  • Contingency table
    • Wikipedia
      A table of frequencies or counts. In a two-way contingency table, sub-categories of one characteristic are indicated horizontally (in rows) and subcategories of another characteristic are indicated vertically (in columns). Tests of association between the characteristics can be readily applied. The simplest two-way contingency table is the 2x2 table, which is used in clinical trials to compare dichotomous outcomes, such as death, for an experimental intervention and control group.
      A two-variable table with cross-tabulated data.
  • Contingent valuation
    • Wikipedia
      Is a method of valuing the benefits of health services based on estimates of the maximum amount that people would be willing to pay for the availability of a service or the minimum amount that they would accept as compensation for not having the service available.
  • Continuous data
    • Data with a potentially infinite number of possible values within a given range. Height, weight and blood pressure are examples of continuous variables.
  • Continuous variable
    • Wikipedia
      A variable that can theoretically take any value and in practice can take a large number of values with small differences between them (e.g., height). Continuous variables are also sometimes called interval data.
      Data which are measured on a continuous scale. They are numbers that can be added, subtracted, multiplied and divided.
  • Contraception
    • MeSH
      Prevention of conception by blocking fertility temporarily, or permanently (sterilization, reproductive). Common means of reversible contraception include natural family planning methods; contraceptive agents; or contraceptive devices.
  • Contraceptive agents
    • MeSH
      Chemical substances that prevent or reduce the probability of conception.
      Also called contraceptives.
  • Contraceptive methods
    • MeSH
      Contraceptive methods include clinic and supply (modern) methods and non-supply (traditional) methods. Clinic and supply methods include female and male sterilization, intrauterine devices (IUDs), hormonal methods (oral pills, injectables, and hormone-releasing implants, skin patches and vaginal rings), condoms and vaginal barrier methods (diaphragm, cervical cap and spermicidal foams, jellies, creams and sponges). Traditional methods include rhythm, withdrawal, abstinence and lactational amenorrhea.
  • Contraceptive prevalence
    • The percentage of women aged 15-49 years, married or in-union, who are currently using, or whose sexual partner is using, at least one method of contraception, regardless of the method used.
      Contraceptive prevalence rate is the proportion of women of reproductive age who are using (or whose partner is using) a contraceptive method at a given point in time.
      Percentage of couples currently using a contraceptive method.
  • Contract
    • MeSH - Wikipedia
      A written, dated, and signed agreement between two or more involved parties that sets out any arrangements on delegation and distribution of tasks and obligations and, if appropriate, on financial matters. The protocol may serve as the basis of a contract.
      Agreements between two or more parties, especially those that are written and enforceable by law.
  • Contract research organization
    • Wikipedia
      A person or an organization (commercial, academic, or other) contracted by the sponsor to perform one or more of a sponsor's trial-related duties and functions.
  • Contraindication
    • Wikipedia
      A specific circumstance when the use of certain treatments could be harmful.
  • Control
    • In a controlled trial: a participant in the arm that acts as a comparator for one or more experimental interventions. Controls may receive placebo, no treatment, standard treatment, or an active intervention, such as a standard drug.
      In a case-control study: a person in the group without the disease or outcome of interest.
      In statistics: to adjust for, or take into account, extraneous influences or observations.
  • Control animal
    • An animal in a study that does not receive the treatment being tested. Comparing the health of control animals with the health of treated animals allows researchers to evaluate the effects of a treatment more accurately.
  • Control event rate
    • Wikipedia
      In epidemiology and biostatistics, the control event rate (CER) is a measure of how often a particular statistical event (such as response to a drug, adverse event or death) occurs within the scientific control group of an experiment.
  • Control group
    • MeSH - Wikipedia
      The standard by which experimental observations are evaluated. In many clinical trials, one group of patients will be given an experimental drug or treatment, while the control group is given either a standard treatment for the illness or a placebo.
      In a controlled trial: the arm that acts as a comparator for one or more experimental interventions. (Also called comparison group.)
      In a case-control study: the group without the disease or outcome of interest. (Also called comparison group.)
      Groups that serve as a standard for comparison in experimental studies. They are similar in relevant characteristics to the experimental group but do not receive the experimental intervention.
  • Control program
    • In communicable (infectious) diseases: programs aimed at reducing or eliminating the disease.
  • Controlled before and after study
    • A non-randomized study design where a control population of similar characteristics and performance as the intervention group is identified. Data are collected before and after the intervention in both the control and intervention groups.
  • Controlled clinical trial
    • MeSH - Wikipedia
      A clinical study that includes a comparison (control) group. The comparison group receives a placebo, another treatment, or no treatment at all.
      An experiment or clinical trial that includes a comparison (control) group.
      Clinical trials involving one or more test treatments, at least one control treatment, specified outcome measures for evaluating the studied intervention, and a bias-free method for assigning patients to the test treatment. The treatment may be drugs, devices, or procedures studied for diagnostic, therapeutic, or prophylactic effectiveness. Control measures include placebos, active medicines, no-treatment, dosage forms and regimens, historical comparisons, etc. When randomization using mathematical techniques, such as the use of a random numbers table, is employed to assign patients to test or control treatments, the trials are characterized as randomized controlled trials as topic.
      Controlled clinical trial [MeSH - publication type]: work consisting of a clinical trial involving one or more test treatments, at least one control treatment, specified outcome measures for evaluating the studied intervention, and a bias-free method for assigning patients to the test treatment. The treatment may be drugs, devices, or procedures studied for diagnostic, therapeutic, or prophylactic effectiveness. Control measures include placebos, active medicine, no-treatment, dosage forms and regimens, historical comparisons, etc. When randomization using mathematical techniques, such as the use of a random numbers table, is employed to assign patients to test or control treatments, the trial is characterized as a randomized controlled trial.
  • Controlled trial
    • Wikipedia
      A clinical trial that has a control. Such trials are not necessarily randomized.
      Control is a standard against which experimental observations may be evaluated. In clinical trials, one group of participants is given an experimental drug, while another group (i.e., the control group) is given either a standard treatment for the disease or a placebo.
  • Convenience sample
    • A group of individuals being studied because they are conveniently accessible in some way. This could make them particularly unrepresentative, as they are not a random sample of the whole population. A convenience sample, for example, might be all the people at a certain hospital, or attending a particular support group. They could differ in important ways from the people who haven't been brought together in that way: they could be more or less sick, for example.
  • Convenience survey
    • Survey that is not based on a randomly selected, representative sample, but rather on data from households/individuals that can easily be reached or observed (e.g. people standing in a food-distribution queue).
  • Conventional treatment
    • Whatever the standard or usual treatment is for a particular condition at that time.
  • Coordinating committee
    • A committee that a sponsor may organize to coordinate the conduct of a multicenter trial.
  • Coordinating investigator
    • An investigator assigned the responsibility for the coordination of investigators at different centers participating in a multicenter trial.
  • Copyright
    • MeSH - Wikipedia
      A set of exclusive rights granted to the author or creator of an original work, including the right to copy, distribute and adapt the work.
      The exclusive right, granted by law for a certain number of years, to make and dispose of copies of a literary, musical or artistic work. In the United States the copyright is granted for the life of the author plus 50 years. In the case of a joint work, it is for the life of the last joint author to die, plus 50 years. In either case the copyright runs until the end of the calendar year 50 years after the author's death.
  • Corrected and republished article
    • Corrected and republished article [MeSH - publication type]: work that is the republication of an article to correct, amplify, or restore text and data of the originally published article.
  • Correlation
    • Wikipedia
      The strength and direction of the association between two variables. Correlation does not mean causation.
  • Correlation coefficient
    • Wikipedia
      A statistic designed to measure the size and direction of the association between two variables. The value varies between 0 and ± 1 (1 means complete correlation).
  • Cost allocation
    • MeSH - Wikipedia
      A process of attributing cost to particular cost centers.
      The assignment, to each of several particular cost-centers, of an equitable proportion of the costs of activities that serve all of them. Cost-center usually refers to institutional departments or services.
  • Cost-benefit analysis
    • MeSH - Wikipedia
      A type of economic study design in which both costs and benefits of interventions are expressed in monetary units, allowing direct comparison of competing interventions.
      A form of economic evaluation through which questions primarily of allocative efficiency are addressed. Costs and outcomes are valued in a commensurate unit, often money, through techniques such as contingent valuation. This allows one to assess whether an intervention is worthwhile. Cost-benefit analysis provides a broader comparison between alternative claims on limited (societal) resources, enabling such comparisons to be made between treatment options within health care and even with options in other public sectors. Even if not everything can be valued in monetary terms, a cost-benefit framework is still useful as all impacts on costs and benefits can be laid out in a “balance sheet” to highlight where trade offs can be, or are being, made between tangible items (usually costs) and some intangibles.
      A method of comparing the cost of a program with its expected benefits in dollars (or other currency). The benefit-to-cost ratio is a measure of total return expected per unit of money spent. This analysis generally excludes consideration of factors that are not measured ultimately in economic terms. Cost effectiveness compares alternative ways to achieve a specific set of results.
  • Cost control
    • MeSH
      The containment, regulation, or restraint of costs. Costs are said to be contained when the value of resources committed to an activity is not considered excessive. This determination is frequently subjective and dependent upon the specific geographic area of the activity being measured.
  • Cost-effectiveness acceptability curve
    • The cost-effectiveness acceptability is plotted on a graph that relates the maximum one is willing to pay for a particular treatment alternative (e.g., how many dollars one is willing to pay to gain 1 life-year) on the x-axis to the probability that a treatment alternative is cost-effective compared with all other treatment alternatives on the y-axis. The curves are generated from uncertainty around the point estimates of costs and effects in trial-based economic evaluations or uncertainty around values for variables used in decision analytic models. As one is willing to pay more for health outcomes, treatment alternatives that initially might be considered unattractive (e.g., a high cost per life-year saved) will have a higher probability of becoming more cost-effective. Cost-effectiveness acceptability curves are a convenient method of presenting the effect of uncertainty on economic evaluation results on a single figure instead of through the use of numerous tables and figures of sensitivity analyses.
  • Cost-effectiveness analysis
    • Wikipedia
      A type of economic study design in which the net monetary costs of a health care intervention per unit measure of clinical outcome or effectiveness allows direct comparison of competing interventions.
      This form of analysis seeks to determine the costs and effectiveness of surveillance and response strategies and activities. It can be used to compare similar or alternative strategies and activities to determine the relative degree to which they will obtain the desired objectives or outcomes. The preferred strategy or action is one that has the least cost to produce a given level of effectiveness, or provides the greatest effectiveness for a given level of cost.
      A form of economic evaluation applicable strictly only when outcomes are one dimensional and measured in naturally occurring units, such as changes in blood pressure or mortality. Within a given budget, a lower cost effectiveness ratio is better as more health can be produced by implementing that alternative. Where one program is both more expensive and more effective than its comparator, an incremental ratio can be calculated that depicts the extra cost per unit of outcome obtained, in comparing one treatment option to another. In this case, a value judgment will be required to assess whether the extra unit of outcome is worthwhile.
  • Cost-effectiveness efficiency frontier
    • The cost and effectiveness results of each treatment alternative from an economic evaluation can be graphed on a figure known as the cost-effectiveness plane. The cost-effectiveness plane plots cost on the vertical axis (i.e., positive infinity at the top and negative infinity and the bottom) and effects such as life-years on the horizontal axis (i.e., negative infinity at the far left and positive infinity at the far right). One treatment alternative such as usual care is plotted at the origin (i.e., 0, 0), and all other treatment alternatives are plotted relative to the treatment at the origin. Treatment alternatives are considered dominated if they have both higher costs and lower effectiveness relative to any other. Line segments can be drawn connecting the nondominated treatment alternatives and the combination of line segments that join these nondominated treatment alternatives is referred to as the cost-effectiveness efficiency frontier. Constructed in this way, any treatment alternative that lies above the cost-effectiveness efficiency frontier is considered to be inefficient (dominated) by a treatment alternative or combination of alternatives on the efficiency frontier.
  • Cost-minimization analysis
    • Wikipedia
      Cost-minimization is the simplest of the pharmacoeconomics tools and is applied when comparing two drugs of equal efficacy and equal tolerability.
      An economic analysis conducted in situations in which the consequences of the alternatives are identical, and the only issue is their relative costs.
      A specific type of cost effectiveness analysis in which the outcomes of the two (or more) comparators are assumed equal, thereby resulting in an assessment based solely on comparative cost. Making the assumption of equal outcomes can be risky, as such assumptions rarely hold in practice.
  • Cost of illness
    • MeSH
      Total costs incurred by a society due to a specific disease.
      The personal cost of acute or chronic disease. The cost to the patient may be an economic, social, or psychological cost or personal loss to self, family, or immediate community. The cost of illness may be reflected in absenteeism, productivity, response to treatment, peace of mind, quality of life, etc. It differs from health care costs, meaning the societal cost of providing services related to the delivery of health care, rather than personal impact on individuals.
  • Cost-utility analysis
    • Wikipedia
      An economic analysis that expresses effects as overall health improvement and describes how much it costs for some additional utility gain (e.g. cost per additional quality-adjusted life-year).
      A form of economic evaluation that, compared with cost effectiveness or cost minimization analysis, enables broader comparisons to be made between treatments for different disease groups. Multi-dimensional health outcomes are reduced to a single index using health utilities and expressed as quality adjusted life years (QALYs), disability adjusted life years (DALYs) or healthy years equivalents (HYEs). Cost per unit of outcome ratios can then be derived that depict the costs required to obtain one QALY.
  • Coverage
    • Share of population eligible for health care benefits (in-kind) under public programs.
  • Coverage of vital registration of deaths
    • Percentage of estimated total deaths that are 'counted' through vital registration system.
  • Credentialing
    • MeSH - Wikipedia
      The process of establishing the qualifications of licensed professionals, organizational members or organizations, and assessing their background and legitimacy.
      The recognition of professional or technical competence through registration, certification, licensure, admission to association membership, the award of a diploma or degree, etc.
  • Credibility
    • Wikipedia
      In qualitative research, a term used instead of validity to reflect whether the investigators engaged thoroughly and sensitively with the material and whether the investigators’ interpretations are credible. Signs of credibility can be found not only in the procedural descriptions of methodology but also through an assessment of the coherence and depth of the findings reported.
  • Criteria of causation
    • Wikipedia
      Criteria of causation refer to a set of criteria used to assess the strength of a relation between a cause and an effect.
  • Critical appraisal
    • Wikipedia
      The process of assessing and interpreting evidence by systematically considering its validity, results, and relevance.
  • Critical appraisal criteria
    • Critical appraisal criteria are checklists or standards that are used to evaluate research evidence. Critical appraisal criteria can be applied to assess the value of a single study, or they are used to appraise several studies as part of the process of systematic review. Critical appraisal criteria address different variables, depending on the nature and purpose of the research, and the expectations and priorities of the reviewers.
  • Critiquing
    • A strategy for changing clinician behavior. A decision support approach in which the computer evaluates a clinician’s decision and generates an appropriateness rating or an alternative suggestion.
  • Cross-border health risks
    • This term is used to describe risks to human health that cross national borders. Examples include risks from climate change and the illegal drugs trade, as well as cross-border movements of people, which can lead to the spread of communicable diseases such as HIV/AIDS, malaria, TB and influenza.
  • Cross-cultural comparison
    • MeSH
      Comparison of various psychological, sociological, or cultural factors in order to assess the similarities or diversities occurring in two or more different cultures or societies.
  • Crossover randomized trial
    • Wikipedia
      A trial in which participants receive one treatment and have outcomes measured, and then receive an alternative treatment and have outcomes measured again. The order of treatments is randomly assigned. Sometimes a period of no treatment is used before the trial starts and in between the treatments (washout periods) to minimize interference between the treatments (carry over effects). Interpretation of the results from crossover randomized controlled trials (RCTs) can be complex.
  • Crossover study
    • MeSH - Wikipedia
      A type of clinical trial comparing two or more interventions in which the participants, upon completion of the course of one treatment, are switched to another. For example, for a comparison of treatments A and B, the participants are randomly allocated to receive them in either the order A, B or the order B, A. Particularly appropriate for study of treatment options for relatively stable health problems. The time during which the firs interventions is taken is known as the first period, with the second intervention being taken during the second period.
      Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given.
  • Cross-sectional study
    • MeSH - Wikipedia
      An observational study design in which measurements are made on a single occasion.
      A study design that involves surveying a population about an exposure, or condition, or both, at one point in time. It can be used for assessing prevalence of a condition in the population.
      Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with longitudinal studies which are followed over a period of time.
  • Cross-tabulation table
    • Wikipedia
      Frequency distribution tables that examine the relationship between several of the variables at once, for better description of the data or in order to look for differences or relevant associations.
  • Crude birth rate
    • Wikipedia
      The ratio between the number of live births in a population during a given year and the total mid-year population for the same year, usually multiplied by 1,000.
      The number of births over a given period divided by the person-years lived by the population over that period. It is expressed as number of births per 1,000 population. CBR = (births in a period / population of person-years over that period).
  • Crude divorce rate
    • Wikipedia
      The number of divorces per 1,000 population in a given year.
  • Crude marriage rate
    • The number of marriages per 1,000 population in a given year.
  • Crude mortality rate
    • Wikipedia
      Mortality rate among all age groups and due to all causes. Often abbreviated to CMR.
      The ratio between the number of deaths in a population during a given year and the total mid-year population for the same year, usually multiplied by 1,000.
      The number of deaths per 1,000 population in a given year.
      Also called crude death rate.
  • Crude prevalence rate
    • A crude prevalence rate is defined as the number of specified risk factor occurrences (i.e. daily smokers) over a specified period of time (e.g. a year) divided by the total population sampled. Crude prevalence rates are usually expressed as per cent of population sampled and may be calculated for males, females, persons or some other subset of the population. Example: Crude rate of current daily smokers (%) in population X = number of current daily smokers / total population sampled x 100
  • Crude rate
    • Term used when results have not been adjusted for confounding factors.
      Rate of any demographic event computed for an entire population.
  • Cumulative frequency
    • In a frequency distribution, the number or proportion of cases or events with a particular value or in a particular class interval, plus the total number or proportion of cases or events with smaller values of the variable.
  • Cumulative frequency curve
    • A plot of the cumulative frequency rather than the actual frequency for each class interval of a variable. This type of graph is useful for identifying medians, quartiles, and other percentiles.
  • Cumulative incidence
    • Wikipedia
      The probability that a particular event, such as occurrence of a particular disease, has occurred before a given time. It is equivalent to the incidence, calculated using a period of time during which all of the individuals in the population are considered to be at risk for the outcome. It is sometimes also referred to as the incidence proportion.
      Incidence proportion (cumulative incidence) is the proportion of people who develop a condition within a fixed time period. An incidence proportion is synonymous with risk. For example, the proportion of people who develop a condition during their lifespan represents the lifetime risk of disease.
  • Cumulative meta-analysis
    • A meta-analysis in which studies are added one at a time in a specified order (e.g. according to date of publication or quality) and the results are summarized as each new study is added. In a graph of a cumulative meta-analysis, each horizontal line represents the summary of the results as each study is added, rather than the results of a single study.
      A type of meta-analysis in which studies are sequentially pooled by adding each time one new study according to an ordered variable. For instance, if the ordered variable is the year of publication, studies will be ordered by it; then, a pooling analysis will be done every time a new article appears. It shows the evolution of the pooled estimate according to the ordered variable. Other common variables used in cumulative meta-analysis are the study quality, the risk of the outcome in the control group, the size of the difference between the groups, and other covariates (for example, mean time to treatment).
  • Curriculum
    • MeSH - Wikipedia
      In formal education, a curriculum is the set of courses, and their content, offered at a school or university.
      A course of study offered by an educational institution.