Evaluating the outcomes of a community-based health literacy intervention for hypertension and diabetes in Harare, Zimbabwe: a cluster randomized controlled trial

Health literacy interventions delivered by community health workers-(CHWs) can significantly improve lifestyle modification and medication adherence for non-communicable diseases. This study evaluated the outcomes of a CHW-led health literacy intervention among diabetes and hypertension patients in Harare, Zimbabwe. A cluster randomized controlled trial was conducted across six clinics. The intervention included four structured education sessions and monthly home visits and was delivered over six months. Primary outcomes were adherence to lifestyle modifications and medication adherence; secondary outcomes were blood pressure and blood glucose control. Data analysis was done under the intention to treat principle. Differences between groups were compared using chi-square and t-tests. Six hundred and forty-three (643) participants were recruited (intervention = 321; control = 322). At follow-up, adherence to lifestyle modifications was significantly higher in the intervention compared to the control group for weight management (70% vs. 40%,); low-salt diet (65% vs. 36%); low-fat diet (60% vs. 30%); physical activity (80% vs. 50%); alcohol moderation (85% vs. 70%); and fruit/vegetable intake (75% vs. 45%). Medication adherence (59% vs. 36%) and blood pressure control (62% vs. 41%) were higher in intervention compared to control group, but there were no significant differences in blood glucose control and adherence to non-smoking. The CHW-led health literacy intervention was associated with improvements in adherence to recommended lifestyle modifications, medication adherence, and blood pressure control. These findings support the integration of CHWs into NCD care models in urban Zimbabwe and other low resource settings.