Marleen E. Hendriks

Hypertension in Sub-Saharan Africa: Cross-Sectional Surveys in Four Rural and Urban Communities

Background Cardiovascular disease (CVD) is the leading cause of adult mortality in low-income countries but data on the prevalence of cardiovascular risk factors such as hypertension are scarce, especially in sub-Saharan Africa (SSA). This study aims to assess the prevalence of hypertension and determinants of blood pressure in four SSA populations in rural Nigeria and Kenya, and urban Namibia and Tanzania. Methods and Findings We performed four cross-sectional household surveys in Kwara State, Nigeria; Nandi district, Kenya; Dar es Salaam, Tanzania and Greater Windhoek, Namibia, between 2009–2011. Representative population-based samples were drawn in Nigeria and Namibia. The Kenya and Tanzania study populations consisted of specific target groups. Within a final sample size of 5,500 households, 9,857 non-pregnant adults were eligible for analysis on hypertension. Of those, 7,568 respondents ≥18 years were included. The primary outcome measure was the prevalence of hypertension in each of the populations under study. The age-standardized prevalence of hypertension was 19.3% (95%CI:17.3–21.3) in rural Nigeria, 21.4% (19.8–23.0) in rural Kenya, 23.7% (21.3–26.2) in urban Tanzania, and 38.0% (35.9–40.1) in urban Namibia. In individuals with hypertension, the proportion of grade 2 (≥160/100 mmHg) or grade 3 hypertension (≥180/110 mmHg) ranged from 29.2% (Namibia) to 43.3% (Nigeria). Control of hypertension ranged from 2.6% in Kenya to 17.8% in Namibia. Obesity prevalence (BMI ≥30) ranged from 6.1% (Nigeria) to 17.4% (Tanzania) and together with age and gender, BMI independently predicted blood pressure level in all study populations. Diabetes prevalence ranged from 2.1% (Namibia) to 3.7% (Tanzania). Conclusion Hypertension was the most frequently observed risk factor for CVD in both urban and rural communities in SSA and will contribute to the growing burden of CVD in SSA. Low levels of control of hypertension are alarming. Strengthening of health care systems in SSA to contain the emerging epidemic of CVD is urgently needed.

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.

Step-by-step guideline for disease-specific costing studies in low- and middle-income countries: a mixed methodology

Background Disease-specific costing studies can be used as input into cost-effectiveness analyses and provide important information for efficient resource allocation. However, limited data availability and limited expertise constrain such studies in low- and middle-income countries (LMICs). Objective To describe a step-by-step guideline for conducting disease-specific costing studies in LMICs where data availability is limited and to illustrate how the guideline was applied in a costing study of cardiovascular disease prevention care in rural Nigeria. Design The step-by-step guideline provides practical recommendations on methods and data requirements for six sequential steps: 1) definition of the study perspective, 2) characterization of the unit of analysis, 3) identification of cost items, 4) measurement of cost items, 5) valuation of cost items, and 6) uncertainty analyses. Results We discuss the necessary tradeoffs between the accuracy of estimates and data availability constraints at each step and illustrate how a mixed methodology of accurate bottom-up micro-costing and more feasible approaches can be used to make optimal use of all available data. An illustrative example from Nigeria is provided. Conclusions An innovative, user-friendly guideline for disease-specific costing in LMICs is presented, using a mixed methodology to account for limited data availability. The illustrative example showed that the step-by-step guideline can be used by healthcare professionals in LMICs to conduct feasible and accurate disease-specific cost analyses.Background Disease-specific costing studies can be used as input into cost-effectiveness analyses and provide important information for efficient resource allocation. However, limited data availability and limited expertise constrain such studies in low- and middle-income countries (LMICs). Objective To describe a step-by-step guideline for conducting disease-specific costing studies in LMICs where data availability is limited and to illustrate how the guideline was applied in a costing study of cardiovascular disease prevention care in rural Nigeria. Design The step-by-step guideline provides practical recommendations on methods and data requirements for six sequential steps: 1) definition of the study perspective, 2) characterization of the unit of analysis, 3) identification of cost items, 4) measurement of cost items, 5) valuation of cost items, and 6) uncertainty analyses. Results We discuss the necessary tradeoffs between the accuracy of estimates and data availability constraints at each step and illustrate how a mixed methodology of accurate bottom-up micro-costing and more feasible approaches can be used to make optimal use of all available data. An illustrative example from Nigeria is provided. Conclusions An innovative, user-friendly guideline for disease-specific costing in LMICs is presented, using a mixed methodology to account for limited data availability. The illustrative example showed that the step-by-step guideline can be used by healthcare professionals in LMICs to conduct feasible and accurate disease-specific cost analyses.

Improving Maternal Care through a State-Wide Health Insurance Program: A Cost and Cost-Effectiveness Study in Rural Nigeria.

Background While the Nigerian government has made progress towards the Millennium Development Goals, further investments are needed to achieve the targets of post-2015 Sustainable Development Goals, including Universal Health Coverage. Economic evaluations of innovative interventions can help inform investment decisions in resource-constrained settings. We aim to assess the cost and cost-effectiveness of maternal care provided within the new Kwara State Health Insurance program (KSHI) in rural Nigeria. Methods and Findings We used a decision analytic model to simulate a cohort of pregnant women. The primary outcome is the incremental cost effectiveness ratio (ICER) of the KSHI scenario compared to the current standard of care. Intervention cost from a healthcare provider perspective included service delivery costs and above-service level costs; these were evaluated in a participating hospital and using financial records from the managing organisations, respectively. Standard of care costs from a provider perspective were derived from the literature using an ingredient approach. We generated 95% credibility intervals around the primary outcome through probabilistic sensitivity analysis (PSA) based on a Monte Carlo simulation. We conducted one-way sensitivity analyses across key model parameters and assessed the sensitivity of our results to the performance of the base case separately through a scenario analysis. Finally, we assessed the sustainability and feasibility of this program’s scale up within the State’s healthcare financing structure through a budget impact analysis. The KSHI scenario results in a health benefit to patients at a higher cost compared to the base case. The mean ICER (US

Costs of cardiovascular disease prevention care and scenarios for cost saving: a micro-costing study from rural Nigeria.

46.4/disability-adjusted life year averted) is considered very cost-effective compared to a willingness-to-pay threshold of one gross domestic product per capita (Nigeria, US

Target organ damage among hypertensive adults in rural Nigeria: a cross-sectional study

2012, 2,730). Our conclusion was robust to uncertainty in parameters estimates (PSA: median US

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

49.1, 95% credible interval 21.9–152.3), during one-way sensitivity analyses, and when cost, quality, cost and utilization parameters of the base case scenario were changed. The sustainability of this program’s scale up by the State is dependent on further investments in healthcare. Conclusions This study provides evidence that the investment made by the KSHI program in rural Nigeria is likely to have been cost-effective; however, further healthcare investments are needed for this program to be successfully expanded within Kwara State. Policy makers should consider supporting financial initiatives to reduce maternal mortality tackling both supply and demand issues in the access to care.

Costs and Cost-Effectiveness of Hypertension Screening and Treatment in Adults with Hypertension in Rural Nigeria in the Context of a Health Insurance Program.

Objective: To assess the costs of cardiovascular disease (CVD) prevention care according to international guidelines, in a primary healthcare clinic in rural Nigeria, participating in a health insurance programme. Methods: A micro-costing study was conducted from a healthcare provider perspective. Activities per patient per year (e.g. consultations, diagnostic tests) were based on clinical practice in the study clinic. Direct (e.g. staff, drugs) and indirect cost items (overheads) for each activity were measured. A cohort study, patient and staff observations, and interviews in the study clinic provided patient resource utilization data. Univariate sensitivity analyses were performed. Scenario analyses evaluated cost-saving options. The main outcome was the costs of CVD prevention care per patient per year. Results: The costs of CVD prevention care were United States dollars (USD) 144 (range 130–158) per patient per year. Direct costs were USD 82 and indirect costs were USD 62. The main cost drivers were drugs (USD 39) and diagnostic tests (USD 36). The costs of hypertension care were USD 118 (107–132) and that of diabetes care USD 263 (236–289) per patient per year. A combination of task-shifting from doctors to nurses, reduction of appointment frequencies, and minimal organ damage screening would result in a direct cost reduction of 42%. Conclusion: This is the first study to report the costs of CVD prevention care in sub-Saharan Africa, based on prospectively collected operational data. The costs observed in our study are unaffordable in many countries in sub-Saharan Africa, highlighting the need for innovative financing mechanisms to fund CVD prevention care.

Feasibility and quality of cardiovascular disease prevention within a community-based health insurance program in rural Nigeria: An operational cohort study

Objectives: To study the prevalence of target organ damage (TOD) in hypertensive adults in a general population in rural Nigeria, to assess determinants of TOD and the contribution of TOD screening to assess eligibility for antihypertensive treatment. Methods: All adults diagnosed with hypertension (n = 387) and a random sample (n = 540) out of all nonhypertensive adults, classified during a household survey in 2009, had a blood pressure measurement and were invited for TOD (myocardial infarction, left ventricular hypertrophy, angina pectoris, kidney disease) screening in 2011. Results: Participation in TOD screening was 51% (n = 196) in respondents with hypertension and 33% (n = 179) in those without hypertension. TOD prevalence in hypertensive and nonhypertensive adults was 32 and 15%, respectively. Hypertension severity was a strong determinant for TOD [grade 1 odds ratio (OR) 2.66, 95% confidence interval (CI)1.04–6.84; grade 2 OR 3.82, 95% CI 1.41–10.36]. Out of 196 hypertensive patients, 151 were untreated, of whom all grade 2 hypertensive patients (n = 71) were eligible for treatment. Screening revealed TOD in 19 out of 80 grade 1 hypertensive respondents (24%), therefore also classifying them as eligible for treatment. TOD screening hypertensive nonrespondents had more severe hypertension than hypertensive respondents, which may have resulted in an underestimation of the true prevalence of TOD among adults with hypertension. Conclusion: A high prevalence of 32% TOD in hypertensive adults in rural Nigeria was observed. Almost a quarter of respondents with grade 1 hypertension were eligible for antihypertensive treatment based on TOD screening findings. As TOD screening is mostly unavailable in sub-Saharan Africa, we propose antihypertensive treatment for all patients with hypertension.

The effect of health insurance and health facility-upgrades on hospital deliveries in rural Nigeria: a controlled interrupted time-series study

BACKGROUND Hypertension is a leading risk factor for death in sub-Saharan Africa. Quality treatment is often not available nor affordable. We assessed the effect of a voluntary health insurance program, including quality improvement of healthcare facilities, on blood pressure (BP) in hypertensive adults in rural Nigeria. METHODS We compared changes in outcomes from baseline (2009) to midline (2011) and endline (2013) between non-pregnant hypertensive adults in the insurance program area (PA) and a control area (CA), through household surveys. The primary outcome was the difference between the PA and CA in change in BP, using difference-in-differences analysis. RESULTS Of 1500 eligible households, 1450 (96.7%) participated, including 559 (20.8%) hypertensive individuals, of which 332 (59.4%) had follow-up data. Insurance coverage increased from 0% at baseline to 41.8% at endline in the PA and remained under 1% in the CA. The PA showed a 4.97 mm Hg (95% CI: -0.76 to +10.71 mm Hg) greater decrease in systolic BP and a 1.81 mm Hg (-1.06 to +4.68 mm Hg) greater decrease in diastolic BP from baseline to endline compared to the CA. Respondents with stage 2 hypertension showed an 11.43 mm Hg (95% CI: 1.62 to 21.23 mm Hg) greater reduction in systolic BP and 3.15 mm Hg (-1.22 to +7.53 mm Hg) greater reduction in diastolic BP in the PA compared to the CA. Attrition did not affect the results. CONCLUSION Access to improved quality healthcare through an insurance program in rural Nigeria was associated with a significant longer-term reduction in systolic BP in subjects with moderate or severe hypertension.