Co-morbidity of 'clinical trial' versus 'real-world' patients using cardiovascular drugs.

Purpose: To examine discrepancies between co-morbidity of patients included in pre-marketing clinical trials of cardiovascular drugs and patients from daily practice, representing the actual users after marketing, and to investigate the availability of data regarding co-morbidity in registration files.

Methods: Data were collected from phase III trials of registration files of 16 drugs, registered in the Netherlands in the period 1985 through 1994 for the indications hypertension, angina pectoris or hypercholesterolemia, and from a general practitioners database. Patients were selected who used drugs from the same therapeutic classes for the same indication as the patients in the pre-marketing trials. Prevalences of concomitant cardiovascular, endocrine and metabolic diseases were compared between pre- and postmarketing populations. Discrepancies were defined as more than 10% difference in prevalences.

Results: Data regarding co-morbidity were present in 13 out of 16 registration files and differed in format of reporting. For all indications, coexisting cardiovascular, endocrine and metabolic diseases were less prevalent in the pre-marketing populations, except ischemic heart disease, which was more prevalent coexisting with angina pectoris and hypercholesterolemia. Discrepancies were found for hypertensive disease, heart failure, diabetes mellitus and myocardial infarction.

Conclusions: Phase III trials testing cardiovascular drugs included patients with concomitant cardiovascular, endocrine and metabolic diseases, but discrepancies were present with patients in daily practice. Development of guidelines for uniform collection and reporting of co-morbidity data in pre-marketing trials is recommended, as well as further utilization of data.