Misleading meta-analysis

Abstract

The table compares the meta-analyses of trials of magnesium and streptokinase after myocardial infarction. Trials were cumulatively included until the treatment effect was significant at P<0.001. For magnesium, seven small trials whose results were published in the 1980s were sufficient to establish the effect. Although trials were larger in the case of fibrinolytic treatment, twice as many studies and two decades were necessary to reach the same level of significance. Until recently it could …