Economic evaluation for first-line anti-hypertensive medicines: applications for the Philippines

BACKGROUND: Medicines to control hypertension, a leading cause of morbidity and mortality, are a major component of health expenditures in the Philippines. This study aims to review economic studies for first line anti-hypertensive medical treatment without co-morbidities; and discuss practical, informational and policy implications on the use of economic evaluation in the Philippines. METHODS: A systematic literature review was performed using the following databases: MEDLINE, EMBASE, BIOSIS, PubMed, The Cochrane Library, Health Economics Evaluations Database (HEED) and the Centre for Reviews and Dissemination – NHS NICE. Six existing economic analytical frameworks were reviewed and one framework for critical appraisal was developed. RESULTS: Out of 1336 searched articles, 12 fulfilled the inclusion criteria. The studies were summarized according to their background characteristics (year, journal, intervention and comparators, objective/study question, target audience, economic study type, study population, setting and country and source of funding/conflict of interest) and technical characteristics (perspective, time horizon, methodology/modeling, search strategy for parameters, costs, effectiveness measures, discounting, assumptions and biases, results, cost-effectiveness ratio, endpoints, sensitivity analysis, generalizability, strengths and limitations, conclusions, implications and feasibility and recommendations). The studies represented different countries, perspectives and stakeholders. CONCLUSIONS: Diuretics were the most cost-effective drug class for first-line treatment of hypertension without co-morbidities. Although the Philippine Health Insurance Corporation may apply the recommendations given in previous studies (i.e. to subsidize diuretics, ACE inhibitors and calcium channel blockers), it is uncertain how much public funding is justified. There is an information gap on clinical data (transition probabilities, relative risks and risk reduction) and utility values on hypertension and related diseases from middle- and low- income countries. Considering the national relevance of the disease, a study on the costs of hypertension in the Philippines including in-patient, out-patient, out-of-pocket, local government and national government expenditure must be made. Economic evaluation may be incorporated in health technology assessment, planning, proposal development, research, prioritization and evaluation of health programmes. The approaches will vary depending on the policy questions. The information gap calls for building strong economic evaluative capacity in growing economies.