Examining the burden of diabetes and hypertension in Zimbabwe

Background: In the context of the epidemiologic transition, type 2 diabetes and hypertension are part of the ten leading causes of morbidity and mortality in Zimbabwe. However, data on the burden of these conditions in Zimbabwe are to a large extent lacking. This thesis aims to assess the mortality and economic burden of diabetes, hypertension and their associated complications in Zimbabwe using secondary data. Information generated provides preliminary evidence for policy design and developing effective prevention and management programmes for type 2 diabetes and hypertension nationwide. Methods: The thesis consists of five studies. As a starting point, the prevalence of type 2 diabetes and hypertension in Zimbabwe were estimated through 2 systematic reviews with meta-analyses. Study 3 used national mortality data to assess the burden of cardiometabolic diseases (comprised of type 2 diabetes, hypertension and associated metabolic disorders), and model a projection of mortality to 2040. Study 4 examined patient medical records to determine the sociodemographic and clinical characteristics of patients with type 2 diabetes and/or hypertension attending a public hospital and private clinic in Harare. Study 5 utilized public hospital financial statements and inpatient medical records to examine the burden (hospitalization cost and indirect cost) of complications associated with type 2 diabetes and hypertension from a narrow societal perspective (patient and healthcare provider). Main findings: The overall pooled prevalence for type 2 diabetes in Zimbabwe was 5.7%, and 30% for hypertension. Cardiometabolic diseases (CMD) attributed 8.2% (95%CI: 7.7% - 8.7%) of all deaths during 1996 to 2007 (p=0.005). During this period CMD mortality increased by 33.9%. CMD mortality is predicted to increase from 9.6% to 13.7% for males, and from 11.6% to 16.2% in females from 2015 to 2040. Patients with T2DM and/or HTN were mainly overweight and obese (>50%) and did not exercise (>80%). The most common comorbidity in all patients was peripheral neuropathy. Likelihood of patients developing comorbid T2DM and HTN increased with age, family history, abdominal obesity, presence high blood pressure and hyperglycaemia and higher educational attainment. Hospitalization costs increased with complications, and the top three causes of death were renal failure, heart failure and stroke. Average costs (US dollars) for hypertensive patients with no complications were $611 (95%CI: 465 – 8.3), one complication $847 (95%CI: 766 – 936) and two complications $1173 (95%CI: 944 – 1459). Average costs for diabetic patients with one complication were $901 (95%CI: 820 – 989), and two complications $1248 (95%CI: 1009 – 1543). Factors affecting total hospitalization costs included hypertension, having one complication, cardiovascular disease, amputation, dialysis and length of stay. Conclusion Intensive preventive measures directed to reduce obesity, improve management of blood pressure and glucose in patients are urgently required and can result in the reduction of comorbidity and complications associated with T2DM and HTN, thereby decreasing healthcare and patient costs. Interventions targeting patients at high risk of heart failure, stroke and renal failure event would assist in reducing the mortality burden.