Effectiveness of a 3-year community-based intervention for blood pressure reduction among adults: a repeated cross-sectional study with a comparison area.

Raised blood pressure is the leading risk factor for cardiovascular diseases. We aimed to demonstrate the effectiveness of a 3-year community-based healthy lifestyle promotion intervention at a neighbourhood level for blood pressure reduction among adults in the context of a political transition. We conducted repeated cross-sectional surveys including 1880 (940 from each area) participants at baseline and 1977 (1001 in the intervention area; 976 comparison area) participants at follow-up. Data collection was conducted through home visits. Multiple linear regression models were used to identify the intervention effect and factors associated with blood pressure change in each area. The prevalence of hypertension was 4.4% lower (35.8% vs. 31.4%) in the intervention area after 3 years (p = 0.044). The mean systolic and diastolic blood pressures changed significantly in the intervention area, from 132.4 ± 19.2 mmHg at baseline to 130.6 ± 17.7 mmHg at follow-up (p = 0.035) and from 78.7 ± 11.8 mmHg to 76.9 ± 11.1 mmHg (p < 10-3), respectively. In the control group, the mean systolic blood pressure increased from 129.4 ± 17.8 mmHg to 130.4 ± 17.9 mmHg (p = 0.38). A significant protective effect of the intervention on systolic (β = -0.4; 95% CI: -0.76; -0.06) and diastolic blood pressures (β = -0.22; 95% CI: -0.38; -0.07) was found in the intervention area. In the control area, the effect was not significant for systolic blood pressure. Lifestyle intervention at the neighbourhood level, in the context of a sociopolitical transition, was found to be effective for reducing blood pressure in Sousse, Tunisia. This approach could be scaled up and applied in other similar settings. Future research also needs to focus on designing, implementing, and evaluating multisectoral action plans and legislative measures.