Cost-effectiveness of a primary care intervention for depressed females

To date, there is little information about the differential impact of primary care interventions by gender. We conducted an exploratory cost-effectiveness analysis by gender of an intervention to improve recognition and guideline-concordant treatment of depression in primary care.

Primary care practices that did not employ an onsite mental healthcare specialist were randomized to enhanced (intervention) versus usual care. All subjects met study criteria for current major depression. Medical Outcomes Study SF-36 scores were converted into quality-adjusted life years (QALYs) to compare the 1-year effectiveness of enhanced versus usual care by gender. Based on results of previous studies, antidepressant acceptors beginning a new depression treatment episode were the focus of the analysis. Statistical analyses included multivariate regression models controlling for sociodemographic and clinical covariates.

In the main analysis, enhanced care for females was more expensive and more effective than usual care, at an additional cost of $5244 per QALY. For males, enhanced care was essentially cost and outcome neutral compared to usual care. The cost-effectiveness ratio estimates were robust to sensitivity analyses. Psychological side effects to the intervention may partially explain the limited effect of the intervention on outcomes for males.

We consider these results exploratory because the SF-36 to quality-adjusted life year conversion formula is preliminary and because of the relatively small sample size.

The estimated cost-effectiveness ratio of this depression intervention is within the acceptable range for females, but not males. If replicated, these exploratory findings suggest that interventions to improve primary care depression treatment may need to be modified to improve their effectiveness in males while maintaining their effectiveness in females.