Effect of health insurance and facility quality improvement on blood pressure in adults with hypertension in Nigeria: a population-based study.

IMPORTANCE Hypertension is a major public health problem in sub-Saharan Africa, but the lack of affordable treatment and the poor quality of health care compromise antihypertensive treatment coverage and outcomes. OBJECTIVE To report the effect of a community-based health insurance (CBHI) program on blood pressure in adults with hypertension in rural Nigeria. DESIGN, SETTING, AND PARTICIPANTS We compared changes in outcomes from baseline (2009) between the CBHI program area and a control area in 2011 through consecutive household surveys. Households were selected from a stratified random sample of geographic areas. Among 3023 community-dwelling adults, all nonpregnant adults (aged ≥18 years) with hypertension at baseline were eligible for this study. INTERVENTION Voluntary CBHI covering primary and secondary health care and quality improvement of health care facilities. MAIN OUTCOMES AND MEASURES The difference in change in blood pressure from baseline between the program and the control areas in 2011, which was estimated using difference-in-differences regression analysis. RESULTS Of 1500 eligible households, 1450 (96.7%) participated, including 564 adults with hypertension at baseline (313 in the program area and 251 in the control area). Longitudinal data were available for 413 adults (73.2%) (237 in the program area and 176 in the control area). Baseline blood pressure in respondents with hypertension who had incomplete data did not differ between areas. Insurance coverage in the hypertensive population increased from 0% to 40.1% in the program area (n = 237) and remained less than 1% in the control area (n = 176) from 2009 to 2011. Systolic blood pressure decreased by 10.41 (95% CI, -13.28 to -7.54) mm Hg in the program area, constituting a 5.24 (-9.46 to -1.02)-mm Hg greater reduction compared with the control area (P = .02), where systolic blood pressure decreased by 5.17 (-8.29 to -2.05) mm Hg. Diastolic blood pressure decreased by 4.27 (95% CI, -5.74 to -2.80) mm Hg in the program area, a 2.16 (-4.27 to -0.05)-mm Hg greater reduction compared with the control area, where diastolic blood pressure decreased by 2.11 (-3.80 to -0.42) mm Hg (P = .04). CONCLUSIONS AND RELEVANCE Increased access to and improved quality of health care through a CBHI program was associated with a significant decrease in blood pressure in a hypertensive population in rural Nigeria. Community-based health insurance programs should be included in strategies to combat cardiovascular disease in sub-Saharan Africa.