Design, rationale, and baseline characteristics of the Prospective Pravastatin Pooling (PPP) project-A combined analysis of three large-scale randomized trials: Long-Term Intervention With Pravastatin in Ischemic Disease (LIPID), Cholesterol and Recurrent Events (CARE), and West of Scotland Coronary Prevention Study (WOSCOPS)

The Prospective Pravastatin Pooling (PPP) project is a pooled evaluation of 3 large, placebo-controlled, randomized trials of cholesterol-lowering treatment with pravastarin. It is designed to more reliably evaluate the effect of treatment on coronary and all-cause mortality and on total coronary artery disease (CAD) events for specific populations of interest, including women and the elderly. The trials-Long-Term Intervention With Pravastatin in Ischemic Disease trial, the Cholesterol and Recurrent Events trial, and the West of Scotland Coronary Prevention Study-each have common design features, including drug, dose, and duration. The project prospectively defines the objectives, end points, and analytic plans in a protocol developed before results are known of any individual trial. More than 2,000 (or 10%) of the participants in the pooled data set are women, 1,841 are aged ≥70 years at trial entry, and >6,000 have a total cholesterol <5.5 mmol/L (213 mg/dl). The mean low-density lipoprotein cholesterol level is 4.2 mmol/L (162 mg/dl). The mean blood pressure level is 134/81 mm Hg and 20% are current smokers. Half of the PPP participants have had a prior myocardial infarction. More than 7% have a history of diabetes and 26% have a history of hypertension. PPP is projected to have data on about 1,100 CAD deaths, 500 non-CAD deaths, and >1,000 cancers by study completion. Based on a pooled population of 19,768 patients, with approximately 1,600 deaths and 100,000 patient-years of follow-up, PPP should have good power to examine the effects of treatment on total mortality, CAD mortality, and cancer incidence, and ta determine effects on total CAD events in important subgroups including the elderly, women, diabetics, and those with lower serum cholesterol levels (<5.5 mmol/L [213 mg/dl]).