The cost-effectiveness and budget impact of Vietnam's methadone maintenance treatment programme in HIV prevention and treatment among injection drug users.

We analysed the cost-effectiveness and budget impact of the methadone maintenance treatment (MMT) programme in HIV prevention and treatment among injection drug users (DUs) in Vietnam. The costs and health outcomes of providing MMT for opioid-dependent DUs versus non-MMT were estimated using a decision analytical model. Probabilistic sensitivity analysis using Monte Carlo simulation was conducted to justify uncertainties of model parameters simultaneously. The incremental cost-effectiveness ratio (ICER) of MMT in HIV prevention was US$3324 per one averted HIV case. The decision model showed that the cost-effectiveness ratio of MMT and non-MMT strategies was US$480 and US$204 per 1 quality-adjusted life year (QALY), equivalent to 0.43 and 0.18 times the gross domestic product per capita (GDPpc). The ICER for MMT versus non-MMT strategy was US$1964, approximately 1.76 times the GDPpc/QALY, classifying MMT as a cost-effective intervention. At the willingness to pay threshold of three times the GDPpc, the probability of MMT and non-MMT strategies being cost-effective was 80.3 and 19.7%, respectively. The budget impact of scaling up MMT from 2011 to 2015 will be US$97 million for 65% coverage or US$49 million for treating 80,000 DUs. The results indicated that MMT was cost-effective in HIV prevention and treatment among DUs who were opioid dependent.