Cost-effectiveness of injectable opioid treatment<i>v</i>. oral methadone for chronic heroin addiction

Abstract

BACKGROUND: Despite evidence of the effectiveness of injectable opioid treatment compared with oral methadone for chronic heroin addiction, the additional cost of injectable treatment is considerable, and cost-effectiveness uncertain. AIMS: To compare the cost-effectiveness of supervised injectable heroin and injectable methadone with optimised oral methadone for chronic refractory heroin addiction. METHOD: Multisite, open-label, randomised controlled trial. Outcomes were assessed in terms of quality-adjusted life-years (QALYs). Economic perspective included health, social services and criminal justice resources. RESULTS: Intervention costs over 26 weeks were significantly higher for injectable heroin (mean £8995 v. £4674 injectable methadone and £2596 oral methadone; P<0.0001). Costs overall were highest for oral methadone (mean £15 805 v. £13 410 injectable methadone and £10 945 injectable heroin; P = n.s.) due to higher costs of criminal activity. In cost-effectiveness analysis, oral methadone was dominated by injectable heroin and injectable methadone (more expensive and less effective). At willingness to pay of £30 000 per QALY, there is a higher probability of injectable methadone being more cost-effective (80%) than injectable heroin. CONCLUSIONS: Injectable opioid treatments are more cost-effective than optimised oral methadone for chronic refractory heroin addiction. The choice between supervised injectable heroin and injectable methadone is less clear. There is currently evidence to suggest superior effectiveness of injectable heroin but at a cost that policy makers may find unacceptable. Future research should consider the use of decision analytic techniques to model expected costs and benefits of the treatments over the longer term.