RESEARCH ARTICLE The Impact and Cost-Effectiveness of a Four- Month Regimen for First-Line Treatment of Active Tuberculosis in South Africa

Background A 4-month first-line treatment regimen for tuberculosis disease (TB) is expected to have a direct impact on patient outcomes and societal costs, as well as an indirect impact onMyco-bacterium tuberculosis transmission. We aimed to estimate this combined impact in a high TB-burden country: South Africa. Method An individual basedM. tb transmission model was fitted to the TB burden of South Africa using a standard TB natural history framework. Wemeasured the impact on TB burden from 2015–2035 of introduction of a non-inferior 4-month regimen replacing the standard 6-month regimen as first-line therapy. Impact was measured with respect to three separate baselines (Guidelines, Policy and Current), reflecting differences in adherence to TB and HIV treatment guidelines. Further scenario analyses considered the variation in treatment-related parame-ters and resistance levels. Impact was measured in terms of differences in TB burden and Disability Adjusted Life Years (DALYs) averted. We also examined the highest cost at whic