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

BackgroundHypertension 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. ObjectivesTo 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. MethodsIn 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. ResultsAmong 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<0.001). SBP/DBP decreased by -15.7/-6.9 mmHg in the IC and -10.4/-4.6 mmHg in the UC. Target BP was more often achieved in the IC (57.3% vs. 48.1%; OR: 1.4, 95%CI:1.0-2.1). Among SPC users, SBP/DBP decreased by -22.4/-10.5 mmHg. ConclusionPromoting SPC therapy improved blood pressure control, supporting local, targeted implementation as a pragmatic strategy to enhance hypertension management. Summary box, bullet points- In the SOLO care improvement project, SPC initiation was increased and improved blood pressure control in routine primary care. - The real-world implementation and cluster-based comparison enhanced practical relevance and reduced contamination between practices. - Although conducted in a large community health center, generalizability cannot be assumed; the non-blinded, non-randomized design allows residual confounding.