Cost-effectiveness of 3HP Lay Summary

This study assessed the cost-effectiveness of 3HP as a treatment of latent tuberculosis infection (LTBI) or sleeping disease. 3HP combines two drugs – rifapentine and isoniazid – given once weekly for 12 weeks. We did this by analyzing the cost-effectiveness of local practices for LTBI treatment using a mathematical model. We created a model that introduced 3HP to hypothetical patients (not real patients) with LTBI. We compared the cost-effectiveness of 3HP to the existing standard of care in the region; 9 months of twice-weekly isoniazid (9H) given by directly observed therapy. To measure the effectiveness, we used measures of quality of life (quality-adjusted life years (QALYs) and used information we had collected in our previous study in Iqaluit about how many people start and complete treatment.  The costs were measured in 2019 US dollars, obtained primarily from costs obtained in Iqaluit.  We considered costs from the perspective of the Nunavut healthcare system. Secondary health outcomes included estimated TB cases and TB deaths that were avoided using 3HP versus 9H.

All factors considered, we found that the 3HP program was less costly than 9H. The costs were lower (US$628 vs US$924/person), and the health outcomes improved slightly (20.14 vs 20.13 QALYs/person). In comparison to 9H, 3HP treatment resulted in fewer TB cases (27.89 vs 30.16/1000 persons) and fewer TB deaths (2.29 vs 2.48/1000 persons). 3HP completion, initiation and risk of fatal adverse events were the primary drivers of cost-effectiveness

In summary, in Iqaluit, using 3HP instead of 9H for LTBI treatment may result in cost savings and similar or improved health outcomes.