Representation of patients with a migration background in studies on antithrombotic treatment. An analysis of recruitment data from a cluster randomized controlled trial

BACKGROUND: The health status, health awareness and health behavior of persons with a migration background often differ from the autochthonous population. Little is known about the proportion of patients with a migration background (PMB) that participate in primary care studies on oral antithrombotic treatment (OAT) in Germany, and whether the quality of their antithrombotic care differs from patients without a migration background. The aim of this paper was to use the results of a cluster-randomized controlled trial (PICANT) to determine the proportion of PMB at different stages of recruitment, and to compare the results in terms of sociodemographic characteristics and antithrombotic treatment. METHODS: This study used screening and baseline data from the PICANT trial on oral anticoagulation management in GP practices. For this analysis, we determined the proportion of PMB during the recruitment period at stage 1 (screening of potentially eligible patients), stage 2 (eligible patients invited to participate in the trial), and stage 3 (assessment of baseline characteristics of patients participating in the PICANT trial). In addition, we compared patients in terms of sociodemographic characteristics and quality of anticoagulant treatment. Statistical analysis comprised descriptive and bivariate analyses. RESULTS: The proportion of PMB at each recruitment stage declined from 9.1% at stage 1 to 7.9% at stage 2 and 7.3% at stage 3). A lack of German language skills led to the exclusion of half the otherwise eligible PMB. At stages 1 and 3, PMB were younger (stage 1: 70.7 vs. 75.0 years, p<0.001; stage 3: 70.2 vs. 73.5 years, p = 0.013), but did not differ in terms of gender. The quality of their anticoagulant care was comparable (100.0% vs. 99.1% were receiving appropriate OAT, 94.4% vs. 95.7% took phenprocoumon, or warfarin, and the most recent INR measurement of 60.8% vs. 69.3% was within their individual INR range). CONCLUSIONS: In the potentially eligible population and among participants at baseline, the quality of anticoagulant care was high in all groups of patients, which is reassuring. To enable the inclusion of more PMB, future primary care research on OAT in Germany should address how best to overcome language barriers. This will be challenging, particularly because the heterogeneity of PMB means the resulting sample sizes for each specific language group are small. TRIAL REGISTRATION: Current Controlled Trials ISRCTN41847489.