Clinical relevance of the gap between pre-marketing trials and medical practice: the case of the cardiovascular drugs.

OBJECTIVES/

backgroundThe external validity of trial results of new cardiovascular drugs is limited, because the short-term studies are performed with relatively small, highly selected populations. Using qualitative methods, we examined the clinical relevance of under-representation of subgroups of patients, and the underlying arguments.

methodsInterviews with 47 physicians and pharmacists involved in the pre- or post-marketing evaluation of cardiovascular drugs, addressing the issue in general and for two new drugs, losartan and atorvastatin, in particular.

resultsThe respondents were generally familiar with the under-representation of elderly patients, female patients, and patients with comorbidity in pre-marketing trials, but less familiar with details of representation in the cases of losartan and atorvastatin. In particular under-representation of patients with comorbidity was considered relevant. Arguments to confirm or refute the relevance referred to trial methodology, applicability of trial results or aspects of patient treatment. Conditional arguments referred to the aim of the trial, population size, therapeutic drug class or the timing of trials prior to or after drug registration.

conclusionsTo optimise the connection between pre-marketing clinical research and practice, trials should focus more on patient groups relevant to medical practice. If such research is not feasible prior to registration, it should be conducted afterwards. Drug information should allow practitioners to determine variations in the relative effects between subpopulations.