Comparing the cost-effectiveness of different standardized tuberculosis treatment regimens in settings with varying prevalence of drug-resistant tuberculosis

Background: There is a growing need to identify appropriate standardized treatment strategies that will adequately treat drug-resistant TB (DR-TB) and prevent multidrug-resistant TB (MDR-TB).;Results: Strengthening retreatment with second-line drugs was highly cost-effective in Ecuador and Brazil. Adding EMB throughout initial treatment prevented acquired drug resistance and TB deaths, but led to excess cases of blindness.;Conclusion: There is growing evidence that the WHO standard retreatment regimen is inadequate and should be strengthened with second-line drugs.;Methods: We built a Markov model comparing treatment-related morbidities, mortality and costs in Ecuador, Brazil and hypothetical settings with varying prevalence of DR-TB. We compared four treatment strategies: 1) standard WHO-recommended treatment strategy; 2) adding EMB throughout 6-month initial treatment; 3) strengthening WHO standard retreatment with 2 nd-line drugs; and 4) treating failures from initial treatment with a standardized MDR regimen. We also compared four combinations of those strategies. Probabilities of tuberculosis outcomes were derived from published literature. Costs were collected using direct surveys.