Diltiazem in Non-Q-Wave Myocardial Infarction

To the Editor: The Diltiazem Reinfarction Study Group has conducted a well-designed prospective clinical trial comparing diltiazem with placebo in non-Q-wave myocardial infarction (Aug. 14 issue).¹ Although the data were interpreted to indicate a beneficial effect of diltiazem, the analysis employed may not be appropriate to the question asked. The primary end point chosen was the occurrence of reinfarction during a 14-day period. The type of hypothesis examined (no difference between drug groups) can be tested by a chi-square test. Instead, the authors employed life-table analysis, a technique appropriate when both the presence or absence of an end point and…