Life Insurance Companies' Institute for Medical Statistics, Ullevål Hospital, Oslo, Norway.
This paper reports on a meta analysis in twenty-two randomized both single and multifactor trials regarding the effect of designed cholesterol reduction on total mortality and CHD incidence. Per cent reduction in CHD incidence was 2.5 for every per cent associated net reduction in total cholesterol, but was only 0.74% for total mortality. Since total net reduction in cholesterol was about 5% in all trials combined, the number of participants was far too small to demonstrate a significant expected reduction of 4% in total mortality. However, the 4% reduction lies just outside the observed 95% confidence limits of the overall estimate of effect on total mortality (OR = 1.02; CL 0.97, 1.07). It is concluded that cholesterol reduction must be much larger than 5% to be able to reduce the relative risk of CHD substantially and total mortality moderately.