Introduction: Preventive therapy is essential for reducing tuberculosis (TB) burden among people living with HIV (PLWH) in high-burden settings. Short-course preventive therapy regimens, such as three-month weekly rifapentine and isoniazid (3HP) and one-month daily rifapentine and isoniazid (1HP), may help facilitate uptake of preventive therapy for latently infected patients, but the comparative cost-effectiveness of these regimens under different conditions is uncertain.
Methods: We used a Markov state-transition model to estimate the incremental costs and effectiveness of 1HP versus 3HP in a simulated cohort of patients attending an HIV clinic in Uganda, as an example of a low-income, high-burden setting in which TB preventive therapy might be prescribed to PLWH. Our primary outcome was the incremental cost-effectiveness ratio, expressed as 2019 US dollars per disability-adjusted life year (DALY) averted. We estimated cost-effectiveness under different conditions of treatment completion and efficacy of 1HP versus 3HP, latent TB prevalence and rifapentine price.
Results: Assuming equivalent clinical outcomes using 1HP and 3HP and a rifapentine price of $0.21 per 150 mg, 1HP would
cost an additional $4.66 per patient treated. Assuming equivalent efficacy but 20% higher completion with 1HP versus 3HP,
1HP would cost $1,221 per DALY averted relative to 3HP. This could be reduced to $18 per DALY averted if 1HP had 5%
greater efficacy than 3HP and the price of rifapentine were 50% lower. At a rifapentine price of $0.06 per 150 mg, 1HP
would become cost-neutral relative to 3HP.
Conclusions: 1HP has the potential to be cost-effective under many realistic circumstances. Cost-effectiveness depends on rifapentine
price, relative completion and efficacy, prevalence of latent TB and local willingness-to-pay.
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