Methods Evidence from systematic reviews of the clinical effectiveness and cost effectiveness literature provided parameter and cost estimates for the analysis. New data on Health Related Quality of Life (HRQoL) outcomes were estimated from a value of health panel project based on assessment from a sample of the general public. A decision tree model with a one year time horizon was used to synthesise data on retention in each treatment programme and level of drug misuse in order to calculate the incremental cost per QALY of the maintenance therapies. The base case analysis was from a health service perspective.
Results From the health care perspective, the incremental cost-effectiveness ratios for flexible dose MMT and BMT were approximately 14,000 UK Pounds/QALY and 27,000 UK Pounds/QALY respectively when compared to no drug therapy in opiate abusers. A direct comparison of the two treatments resulted in MMT dominating BMT, although the difference in QALYs was very small. Both treatments were dominant compared to no treatment when costs to the criminal justice system were included. These findings were robust to deterministic and probabilistic sensitivity analyses.
Conclusions According to accepted UK thresholds, both types of maintenance therapy were considered cost-effective when compared to no treatment, but MMT was the most cost-effective option. Although this may suggest the sole use of MMT, patient choice is an important factor in maintenance therapy. If MMT is not deemed suitable by the clinician or patient, BMT is a cost-effective alternative if the alternative is continued drug misuse. This analysis, based on meta-analyses of the of the best available effectiveness evidence to date on these treatments for drug abuse, should help policy makers both in the UK and internationally.