COST-UTILITY ANALYSIS OF MAINTENANCE TREATMENT FOR RECURRENT DEPRESSION

This paper presents a cost-utility analysis of three maintenance treat ments for recurrent depression: interpersonal therapy (IPT-M), imipram ine drug therapy (Drug), and a combination of the two. We base our ana lysis on the results of the University of Pittsburgh's Controlled Clin ical Trial of Maintenance Therapies for Recurrent Depression. We const ruct a Markovian state-transition model to incorporate clinical effect iveness into cost and quality-of-life impacts; we assign empirical val ues to the parameters of this model; and we then use Monte Carlo analy sis to compare the relative cost effectiveness of the different mainte nance treatments. For the patients who met the eligibility standards f or the study, Drug maintenance treatment is cost-effective in the stro ngest sense of the term compared to either a placebo group or IPT-M: i t both improves expected lifetime health (measured in quality-adjusted life years, or QALYs) and reduces direct medical costs. This is true even when relatively severe side effects of the drug are considered. C ompared to the placebo group, IPT-M and the combination of IPT-M and D rug each improve expected lifetime health, although in neither case ar e expected direct medical costs reduced. Still, the cost of the result ing health improvements, under $5000/QALY, are very reasonable. A simi lar conclusion holds comparing Drug and IPT-M to IPT-M alone. All of t he above conclusions are quite robust to sensitivity analyses.