 -To perform an economic evaluation, comparing the costs and clinical benefits of methadone and morphine. Researchers will perform an evaluation that incorporates both treatment and potential downstream costs, as well as an examination of clinical benefits that incorporate preferences, to perform an appropriate economic comparison. We postulate that methadone and its associated costs will be cheaper than morphine. However, if one strategy is both more expensive and clinically superior than the other, researchers are prepared to perform an incremental cost-effectiveness analysis. In that case, researchers expect to show that the greater pharmaceutical costs involved with morphine will make its use not be a cost-effective strategy. 