Validity in a community (with outside verification) of primary prevention studies on hypercholesterolemia

The main objective of this study was to determine the degree of similarity between large primary prevention trials of hypercholesterolemia and our population of patients with dyslipidemia, in order to evaluate the external validity of these studies and their applicability to the general population. Descriptive retrospective study. Tafalla Health Center in Navarra (Northern Spain), serving a population of 11 500 inhabitants.Participants. All patients older than 18 years assigned to our health center who had dyslipidemia with no antecedents of ischemic heart disease. The percentage of patients in our sample who satisfied the inclusion criteria used in large clinical trials ranged from 2.4% to 46%, depending on the study: AFCAPS/TexCAPS 1998, 46.2%; HPS 2002, 46.1%; WOSCOPS 1995, 10.9%; HHS 1987, 10.6%; LRC-CPPT 1984, 2.4%. Many of our patients (54%-97%) with dyslipidemia would not have been eligible for inclusion in earlier studies of hyperlipidemia and primary prevention. The external validity (applicability to the general population) of these studies is questionable. Decision-making in clinical practice for the primary prevention of hypercholesterolemia should be based on the risk/benefit ratio of pharmacological treatment.