BACKGROUNDA support group care model including self-financing is a promising strategy to improve care for patients with diabetes or hypertension in resource-constrained settings.OBJECTIVESWe investigated the uptake, feasibility, and impact of a self-financing patient support group care model on cardiometabolic parameters among adult patients with uncontrolled diabetes or hypertension in informal settlements in Nairobi, Kenya.METHODSA two-group prospective quasi-experimental study was conducted. The outcomes were changes in mean glycated haemoglobin (HbA1c), systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index, and waist-hip ratio in control versus intervention communities, assessed 6 months after intervention implementation.RESULTSAt baseline, 118 patients with diabetes (intervention, 60; control, 58) and 176 with hypertension (intervention, 87; control, 89) were enrolled. At endline, 81 patients with diabetes and 137 with hypertension were surveyed. In the intervention arm, HbA1c decreased from 10.8% to 9.0% (mean difference [95% CI]: -1.7 [-2.4, -0.9] p < 0.001) and in the control arm from 10.6% to 9.9% (-0.9 [-1.5, -0.3] p = 0.005). Difference-in-difference analysis showed a notably greater reduction in HbA1c in the intervention arm (-0.942 [0.463] p < 0.05). In the intervention arm, SBP decreased from 155.0 mmHg to 148.7 mmHg (-6.3 [-11.7, -0.9] p = 0.022) and in the control arm, from 160.1 mmHg to 152.5 mmHg (-7.6 [-12.9, -2.3] p = 0.005). DBP in the intervention arm changed from 99.1 mmHg to 97.9 mmHg (-1.1 [4.2, 1.9] p = 0.462) and in the control arm from 99.7 mmHg to 94.8 mmHg (-4.9 [7.8, -2.0] p = 0.001).CONCLUSIONSA self-financing patient support group care model is feasible, improves cardiometabolic parameters and can be a strategy to manage diabetes, hypertension, and other chronic diseases in low-resource settings.