Subgroup analyses of the major clinical endpoints in the program on the surgical control of the hyperlipidemias (POSCH): Overall mortality, atherosclerotic coronary heart disease (ACHD) mortality, and ACHD mortality or myocardial infarction

The Program on the Surgical Control of the Hyperlipidemias (POSCH) was a secondary atherosclerosis intervention trial employing partial ileal bypass surgery as the intervention modality. For this report, we analyzed 105 subgroups in 35 variables in POSCH, chosen predominantly for their potential relationship to the risk of atherosclerotic coronary heart disease (ACHD). We defined potential differential effects as those with: (1) an absolute z-value ⩾2.0 for the subgroup, if the absolute z-value for the overall effect was