AT(1) receptor blockers - Cost-effectiveness within the South African context

Objectives. Hypertension is a leading chronic disease in South Africa. Sign ificant mortality results from this condition and from stroke and ischaemic heart disease in which hypertension plays a major role: The objective of t his study was to evaluate the evidence for the clinically effective and cos t-effective treatment of hypertension, given that the clinician has decided to administer an AT(1) receptor blocker. Methodology. A cost-effectiveness analysis was undertaken from the perspect ive of the funder of health care in the private sector. A predetermined pro tocol defined the study scope, the comparators (candesartan, losartan, vals artan and irbesartan) and the inclusion criteria for peer-reviewed data. Da ta for the clinical efficacy of the comparators, measured as the reduction (mmHg) in sitting diastolic blood pressure (SDBP) achieved, were extracted, statistically assessed and reported. The combinability of the data from di fferent clinical trials was confirmed using analyses of variance. A pharmac oeconomic model was developed by combining these clinical results with Sout h African retail prices and testing the results at a 95% confidence level. Results. Significant difference in clinical effectiveness was found among t he comparators, with the following mean reductions in SDBP observed: candes artan 10.57, irbesartan 9.07, losartan 8.89 and valsartan 7.11 mmHg. Candes artan was found to be significantly more effective than losartan. Valsartan was found to be less effective than the other 3 comparators. No significan t difference was found between irbesartan and either candesartan or losarta n. The reduction in SDBP per R100 spent indicated that candesartan was more cost-effective than the other comparators, among which there were no signi ficant differences. Incremental savings of R5.0 million annually could be a chieved by the funders of private health care for every 100 000 successfull y treated patients using candesartan. Conclusion. Significant differences exist in both the clinical and cost-eff ectiveness measures used in this study for the comparators. The findings fr om the analysis will be valuable in decision-making processes for both the Funders and providers of health care. This analysis can be enhanced further by the inclusion of additional clinical benefits and long-term health outc omes when the relevant data become available.