TY - JOUR T1 - Megatrials are based on a methodological mistake. JF - British Journal of General Practice JO - Br J Gen Pract SP - 429 LP - 431 VL - 46 IS - 408 AU - B G Charlton Y1 - 1996/07/01 UR - http://bjgp.org/content/46/408/429.abstract N2 - Despite their prestige, megatrials are founded upon a methodological error. This is the assumption that randomization of very large numbers of subjects can compensate for deliberately reduced levels of experimental control, but there is no trade-off between size and rigour. Randomized trials are not a 'gold standard' because no method is intrinsically valid-there are good and bad trials. Interpretation of megatrials is always difficult and requires considerable clinical and scientific knowledge. Three fundamental parameters should be considered when evaluating the applicability of a trial to clinical practice: rigour of design; representativeness of the trial population; and homogeneity of the recruited subjects. ER -