Baseline characteristics in stroke patients with atrial fibrillation: clinical trials versus clinical practice

When applying information gathered from medical research to the clinical setting, it is imperative that the sample of the investigated patients be representative of the clinical population. Because of this fact, it is necessary to closely examine the sample's baseline characteristics in clinical trials.

We analysed baseline data of relevant trials investigating considerable proportions of patients with atrial fibrillation (AF) in the secondary stroke prevention: EAFT, SIFA, Active-W, BAFTA, RE-LY, AVERROES, ARISTOTLE and ROCKET AF. For comparing baseline data stroke patients with AF documented in a statutory stroke registry were considered. In a subgroup of patients (members of a large insurance) data on subsequent prescription for oral anticoagulants (oAK) were available.

In the stroke registry (n = 15,886) the mean age was higher than in the selected clinical trials (mean 77.7 versus 70-72 years). Among insurance members (n = 1,828), those with a prescription for oAK (n = 827) were older than patients recruited in clinical trials (mean 75.1 versus 70-72 years). Results also showed that the male sex was overrepresented in clinical trials (59-63% versus 46%). The distribution of vascular risk factors in recent clinical trials was comparable to proportions in the registry (hypertension: 77-85% versus 80%; diabetes mellitus: 20-26% versus 27%).

The majority of stroke patients with AF in the clinical setting are considerably older than those included in clinical trials. While the distribution of vascular risk factors in clinical trials corresponds to proportions observed in clinical practice, an overrepresentation of the male sex in clinical trials is evident.