To the Editor.
—Gore and Dalen1 state that the combined results of US and British physician studies demonstrate a 33% reduction in nonfatal myocardial infarction in male physicians who took aspirin compared with those who did not take aspirin. I believe combining the results of these two trials is misleading for two reasons.In the US physicians' study, there was a 44% decrease in nonfatal myocardial infarctions among aspirin takers.2 But in the British study, there was no decrease.3 The two trials do not support each other; they contradict each other. Combining results completely obscures this fact and makes it (wrongly) appear that the two trials drew similar conclusions.The treatments used in the two trials were not the same. In the British study, pure aspirin was used. In the US study, aspirin buffered with magnesium was used. The inclusion of magnesium may be significant. Numerous studies