Use of opioid substitution therapies in the treatment of opioid use disorder: results of a UK cost-effectiveness modelling study.

Aims: This study investigated the cost-effectiveness of buprenorphine maintenance treatment (BMT) and methadone maintenance treatment (MMT) vs no opioid substitution therapy (OST) for the treatment of opioid use disorder, from the UK National Health Service (NHS)/personal social services (PSS) and societal perspectives over 1 year.

Methods: Cost-effectiveness of OST vs no OST was evaluated by first replicating and then expanding an existing UK health technology assessment model. The expanded model included the impact of OST on infection rates of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection.

Results: Versus no OST, incremental cost-effectiveness ratios (ICERs) for BMT and MMT were £13,923 and £14,206 per quality-adjusted life year (QALY), respectively, from a NHS/PSS perspective. When total costs (NHS/PSS and societal) are considered, there are substantial savings associated with adopting OST; these savings are in excess of £14,032 for BMT vs no OST and £17,174 for MMT vs no OST over 1 year. This is primarily driven by a reduction in victim costs. OST treatment also impacted other aspects of criminality and healthcare resource use.

Limitations: The model's 1-year timeframe means long-term costs and benefits, and the influence of changes over time are not captured.

Conclusions: OST can be considered cost-effective vs no OST from the UK NHS/PSS perspective, with a cost per QALY well below the UK's willingness-to-pay threshold. There were only small differences between BMT and MMT. The availability of two or more cost-effective options is beneficial to retaining patients in OST programs. From a societal perspective, OST is estimated to save over £14,032 and £17,174 per year for BMT and MMT vs no OST, respectively, due to savings in victim costs. Further work is required to fully quantify the clinical and health economic impacts of different OST formulations and their societal impact over the long-term.