Mortality in non‐consenters in a post‐myocardial infarction trial

Abstract. Follow‐up of 270 subjects who declined to participate in a trial of oral anticoagulant therapy after acute myocardial infarction revealed a higher mortality (25.6%) than that for participants in the placebo group (20.2%). The excess mortality in terms of odds ratios was 1.35 (90% confidence interval 1.02‐1.79). Age was the only predictor of death. The event rate from ischaemic cardiovascular disease was lower among non‐consenters than among participants (49.3% vs. 74.8%), as was the rate of death during the first year of follow‐up. In conclusion, the differing mortality and dissimilar patterns of specific causes of death in non‐consenters and placebo‐treated participants emphasize the need for caution in extrapolation of treatment effects to the non‐consenting group. Thus the size of the non‐consenting group has implications for generalization of the overall results. 1990 Blackwell Publishing Ltd