Relation of coronary heart disease incidence and total mortality to plasma cholesterol reduction in randomised trials: use of meta-analysis

The first randomised trials designed to test the effect of plasma cholesterol reduction came out in the mid-sixties and were largely carried out on patients who already had coronary heart disease. The trials were small and had relatively few new incidents of coronary heart disease in the treatment groups. Even in these high risk populations no general agreement on the benefit of cholesterol lowering was reached, and there was even the suggestion of an excess of non-cardiac related deaths in the treated groups. The first meta-analysis of randomised trials of cholesterol lowering, however, found no indication of an excess of cancer or total mortality in the groups treated by diet