Community-Based Interventions to Promote Blood Pressure Control in a Developing Country

Context Physician education and community-based interventions to educate people with hypertension may improve hypertension care in resource-poor settings. Contribution Among 1341 patients living in 12 communities in Pakistan that were randomly assigned to general practitioner education, home health visits by trained lay workers, both, or neither, patients in communities assigned to both interventions had the greatest improvements in systolic blood pressure (10.8 mm Hg) after 2 years. Improvements were similar in all other groups (about 5 mm Hg). Caution Twenty-two percent of patients were lost to follow-up. Implication Home visits by trained lay workers plus physician education deserves further study as a way to improve hypertension control in resource-poor settings. The Editors Cardiovascular disease has, in just a few decades, become the leading cause of death in adults worldwide, accounting for 1 in 5 deaths. Hypertension confers the highest attributable risk for death and disease associated with cardiovascular disease (1, 2). Despite the demonstrated benefits of effective drug treatment (3, 4) and the existence of many clinical practice guidelines (5), hypertension prevention, treatment, and control rates remain suboptimal worldwide (6). The situation is particularly acute in developing countries, such as Pakistan, India, and China, where hypertension has reached epidemic proportionsaffecting more than 20% of the adult population (7)yet control rates are less than 6% (8). Poor health literacy and unhealthy lifestyles, compounded by lack of awareness of hypertension (7), are part of the cause. In addition, the health systems in these countries are often dysfunctional: More than 80% of the expenditure for chronic disease care is out-of-pocket; private care general practitioners (GPs), who primarily treat acute conditions, are the front-line service providers; and national programs for preventing and controlling hypertension are inadequate. Serious deficiencies in management of hypertension also have been identified in the knowledge and practice of health care providers. (9) However, evidence for public health interventions to improve hypertension control rates through patient or physician education in Indo-Asian countries is lacking. We conducted the COBRA-1 (Control of Blood Pressure and Risk Attenuation-1) trial in Karachi, Pakistan, to test the effectiveness of 2 community-based strategies: family-based home health education (HHE), delivered by trained community health workers, to improve population-level health literacy and behaviors, and hypertension management training for GPs. We tested the effect of these interventions, alone and in combination, on blood pressure in adults with hypertension. We hypothesized that HHE would be more effective than no education, that the specially trained GPs would provide more effective care than that usually received in Karachi, and that the combined interventions would provide additional benefit. Methods Study Design and Setting We performed a cluster randomized, controlled trial with a 22 factorial design to determine the effect of family-based HHE and special training for GPs on blood pressure in adults 40 years or older with hypertension. We used a cluster approach because our objective was to assess the effectiveness of both HHE and GP training as health system interventions at a population level, and an individual approach would be prone to contamination of interventions and biased outcomes (10). The Aga Khan University Ethics Review Committee granted ethical approval. The sampling frame is described elsewhere (11). In brief, we used a multistage random sampling technique to select 12 of 4200 low- to middle-income, geographic census-based clusters (mean household monthly income, $70; about 250 households in each cluster) in Karachi, the most populous city in Pakistan (about 16 million inhabitants). We ensured at least a 10-km distance between clusters to minimize the risk for contamination by the intervention. Participants Persons 40 years or older who resided in the 12 clusters and had known hypertension or consistently elevated blood pressure on 2 separate visits (mean of 2 of past 3 measurements of systolic blood pressure 140 mm Hg or diastolic blood pressure 90 mm Hg) were eligible for inclusion. We excluded pregnant women, persons who could not give informed consent, and bed-bound persons. Randomization and Intervention We used computer-generated codes to randomly assign 3 clusters each to the following groups: HHE alone, GP alone, HHE and GP combined, and no intervention. Home Health Education We trained 6 community health workers (1 for each cluster) over 6 weeks in methods for using behavior-changing communication strategies to convey standardized health education messages to all households in clusters assigned to receive HHE. The education status of the workers we employed was consistent with the requirements of the government-sponsored Lady Health Workers Programme of Pakistan (8 or preferably 10 years of schooling) (12). Salary scales and assigned workload were similarly consistent. The health messages included information on the deleterious effects of hypertension and nonpharmacologic interventions for preventing and controlling hypertension and cardiovascular disease, as well as advice on the importance of engaging in moderate physical activity; maintaining normal body weight; reducing salt intake; consuming a diet rich in fruit, vegetables, and low-fat dairy products; reducing intake of saturated and total fat (including suggestions on sample recipes for culturally acceptable and economically feasible food products); and smoking cessation (Appendix 1). The importance of achieving blood pressure targets and adhering to medication and physician follow-up was emphasized. The first HHE session, lasting 90 minutes, was held at a time when all members of the household could be present. Follow-up reinforcement visits of 30 minutes were made every 3 months. Appendix 1. Training Manual for Community Health Workers General Practitioner Education We invited all GPs in the 6 study areas assigned to this intervention to receive training, with the aim of training at least two thirds of the GPs in each area. We considered this proportion to be feasible both for future uptake of the strategy and for assessing the effectiveness of training. Training was a 1-day session that focused on standard treatment algorithms for the stepped-care management of hypertension, which were based on the seventh report of the Joint National Committee (3) and the Fourth Working Party of the British Hypertension Society guidelines (4) and modified for the Indo-Asian population (Appendix 2). The course included components on nonpharmacologic (diet, exercise, weight loss, and smoking cessation) and pharmacologic interventions, prescription of low-cost and appropriate generic drugs, preferential use of single-dose drug regimens, scheduled follow-up visits guided by blood pressure, the stepped-care approach for titrating drugs to achieve target blood pressure, and satisfactory consultation sessions for patients, with explanations of treatment and use of appropriate communication strategies. For managing persons with known hypertension, GPs were advised to review medication and blood pressure; simplify regimens; and aim to return to a regimen that was in line, as reasonably as possible, with that recommended for those with newly diagnosed hypertension. The recommended target blood pressure was <140/90 mm Hg for all patients. Although this diverges from recent guidelines for special subgroups (such as diabetic persons or those with end-organ damage), we reasoned that we needed to keep the intervention, guidelines, and targets simple for both patients and practitioners in a setting where blood pressure control rates are less than 3% (7). The training sessions for GPs used a case-based curriculum and were interactive. We provided a certificate of training at the end of the course. Appendix 2. Training Manual for General Practitioner All study participants were advised to consult a local GP. If participants in the clusters randomly assigned to a trained GP group did not already have a preferred GP, we gave them a list of trained GPs in their cluster from which to choose. However, it remained the participant's choice whether they attended a physician on the list. We did not provide for medications or fee-for-health care services. Participants were blinded to intervention status (training of GP). Neither the patients nor the GPs received reimbursement for participation. Screening and Recruitment All households in each cluster were visited, and we obtained informed consent for screening from all adults 40 years and older, whose blood pressure was then measured 3 times with a calibrated automated device (Omron HEM-737 IntelliSense; Omron Healthcare, Vernon Hills, Illinois) in the sitting position after 5 minutes of rest. Those with known hypertension were invited to participate. Those with elevated blood pressure who were not receiving antihypertensive medication were visited again for remeasurement of blood pressure 1 to 4 weeks after the initial visit. If mean blood pressure remained elevated, these persons were also invited to participate. A routine physical examination was performed, and the following information was collected: smoking status, food frequency, and physical activity by questionnaire, the latter by using the international physical activity questionnaire; blood pressure, measured as described above; anthropometric characteristics (height, weight, and waist and hip circumferences); and fasting blood glucose level (Synchron Cx-7/Delta, Beckman Coulter, Fullerton, California) and lipid profile (Hitachi-912, Roche, Basel, Switzerland) (11). Follow-up Procedures Trained outcomes assessors (who were not part of and had no relationship with the community health worker team) evaluated part