The association between corticosteroid therapy and subsequent infections was calculated by pooling data from 71 controlled clinical trials. The overall rate of infectious complications was 12.7% in the 2,111 patients randomly allocated to systemic corticosteroids and 8.0% in the 2,087 controls (relative risk [RR], 1.6; 95% confidence interval [CI], 1.3-1.9; P 1; P = .03) diseases. The rate was not increased in patients given a daily dose of <10 mg or a cumulative dose of <700 mg of prednisone. With increasing doses the rate of occurrence of infectious complications increased in patients given corticosteroids as well as in patients given placebo, a finding suggesting that not only the corticosteroid but also the underlying disease state account for the steroid-associated infectious complications observed in clinical practic