HIV drug resistance (HIVDR) has significantly increased in Thailand. However, a new generation integrase inhibitor, dolutegravir, has not yet been included in the country's National List of Essential Medicines (NLEM). Since these drugs are high in costs, an economic evaluation is needed to support the decision. This study aims to assess the cost-utility analysis of dolutegravir for HIV-1 infection in Thailand.

A Markov model was developed to evaluate the cost-utility as follows: (i) the current practice of darunavir/ritonavir (DRV/r) + tenofovir (TDF) + lamivudine (3TC); (ii) DRV/r + etravirine (ETR) + TDF + 3TC; (iii) DRV/r + raltegravir (RAL) + TDF + 3TC; (iv) DRV/r + RAL + ETR; and (v) DRV/r + RAL + maraviroc (MVC); (vi) DRV/r + dolutegravir (DTG) + MVC; (vii) DRV/r + DTG + ETR; (viii) DRV/r + DTG + TDF + 3TC. The model incorporated cost data adjusted for 2017 using the consumer price index, and effectiveness data from a review of published studies. Outcomes were measured in life years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs), and future costs and outcomes were discounted at 3 percent per annum. Finally, a probabilistic sensitivity analysis was conducted to deal with uncertainties around the parameters.

All alternative treatment regimens for HIV patients resistant to first- and second-line antiretroviral therapies (ARTs) in Thailand were found to be not cost-effective at the willingness-to-pay (WTP) of THB 160,000/QALY (USD 5,197/QALY). However, the eighth regimen of DRV/r + DTG + TDF + 3TC had the lowest lifetime cost at THB 5.3 million (USD 172,145) while increasing QALY by approximately 14 QALYs.

At a societal WTP of THB 160,000 per QALY gained (USD 5,197 per QALY gained), dolutegravir for HIV patients resistant to first- and second-line ARTs in Thailand was found to be not cost-effective.