COST EFFECTIVENESS OF TENOFOVIR AGAINST ENTECAVIR IN THE TREATMENT OF HEPATITIS B VIRUS INFECTION IN PERU

To compare the cost-effectiveness of tenofovir (TDF) against entecavir (ETV) in the treatment of Hepatitis B virus chronic infection (HBV) in Peru. We developed a Markov model from the perspective of the Peruvian Ministry of Health. We considered a 10 year time horizon, one-year Markov cycles, a 3% discount rate and quality adjusted life years (QALY) as a measure of effectiveness. Costs were calculated in 2015 Peruvian Soles (S/.) and converted to U.S. Dollars (US$). We calculated cost-effectiveness ratios for each treatment and incremental cost-effectiveness ratios (ICER) for TDF compared to ETV. To assess model uncertainty, we conducted one-way sensitivity analyses to evaluate individual cost drivers and probabilistic sensitivity analysis using Monte Carlo simulations. We considered a willingness to pay (WTP) threshold equal to the annual Peruvian Gross Domestic Product (GDP) per-capita (US$ 6 660). Finally, we calculated the net monetary benefit (NMB) considering a WTP range between zero and three times GDP per-capita. We used TreeAge 2015 for the analysis. Treatment with TDF is more effective and less expensive than ETV. Therefore, ETV is dominated by TDF. The cost per QALY with TDF treatment was S/. 1 526 (US$ 448) compared to S/. 4 482 (US$1 314) for ETV. Probabilistic analysis showed that, in 79% of simulations, TDF was more effective, less costly and had an ICER below the WTP threshold. The one-way sensitivity analysis showed that the discount rate was the only influential variable in the model. The NMB was higher for TDF and increased across ranges of WTP. TDF is a dominant strategy compared to ETV in the treatment of HBV chronic infection. A budget impact analysis would be of importance for policy leaders and public health decision-makers to better understand the affordability of implementing this strategy at a national level.