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