TABLE 4. Methods of allocating subjects in randomized controlled trials.

METHOD	LEVEL
COIN TOSSING	*
COLORED BEADS	*
ALTERNATE ALLOCATION	**
EVEN/ODD BIRTHDATE	**
EVEN/ODD MEDICAL RECORD	**
SEALED ENVELOPES	***
SEALED ENVELOPES / THIRD PARTY	***
NUMBERED PLAIN AMPOULES	****
LOCAL COMPUTER	****
FAX / TELEX	****
TELEPHONE	*****

* less rigorous; ***** more rigorous