SOLO study: A single-pill combination strategy in general practice to optimize blood pressure control in a multi-ethnic community

Abstract Background Hypertension is a major modifiable risk factor for cardiovascular disease, yet blood pressure (BP) control remain suboptimal, particularly in socially disadvantaged communities. Guidelines recommend initiating single-pill combination (SPC) therapy to improve adherence and BP control, but uptake in primary care is limited. Objectives To evaluate the SOLO care improvement project, promoting SPC initiation among general practitioners (GPs) in Amsterdam Zuidoost, a disadvantaged, multi-ethnic community in The Netherlands with a high hypertension burden. Methods In a cluster quasi-randomized cluster design, adult hypertensive patients from nine general practices within one health facility were allocated to intervention (IC; n=5) or usual care (UC; n=4). Intervention practices received case-specific guidance on SPC therapy. Outcomes were SPC uptake, changes in systolic and diastolic BP (SBP and DBP), target BP achievement and cardiovascular events. Analyses used intention-to-treat adjusted regression and Cox models, with additional as-treated analysis among SPC users. Results Among 438 patients (mean age 64.5±12.2 years; median follow-up of 367 days [213-467]), SPC initiation was higher in the IC than US (25.1% vs. 9.6%, p