Cost-effectiveness of a randomized trial to treat depression among Latinos

Rising mental health costs have brought with them the pressing need to identify cost-effective treatments. Identifying cost-effective treatments for depression among Latinos is particularly relevant given substantial disparities in access to depression treatment for Latinos compared to non-Latino whites.

The goal of this paper is to (i) compare the cost-effectiveness of telephone and face-to-face cognitive behavioral therapy (CBT) for depression to usual care received in primary care; (ii) compare the cost-effectiveness of telephone CBT directly to face-to-face CBT.

As part of a randomized trial study, primary care patients with depression were randomized into three groups: usual care, telephone CBT and face-to-face CBT. Incremental cost-effectiveness ratios (ICER) between respective groups are computed by dividing the incremental difference in mental health care costs by the incremental difference in mental health outcomes. Mental health care costs are computed as the sum of intervention costs (cost of administering sessions) and non-intervention costs (cost of mental health services used that are not part of the intervention). Prices for different types of mental health services are taken from the 2010 Medical Expenditure Panel Survey. Mental health costs are estimated using two-part models. Mental health outcomes are measured by two depression scales: Patient Health Questionnaire (PHQ-9) and Hopkins Symptom Checklist (HSCL), and are estimated using multiple linear regression models. The standard errors for ICERs are computed using 1000 bootstrapped samples and the delta method.

Each CBT intervention group is significantly more costly compared to usual care in terms of mental health care costs. Face-to-face CBT patients cost USD732 more than usual care, and phone CBT patients cost USD237 more than usual care. In terms of effectiveness, both intervention groups are associated with significantly reduced (improved) scores in PHQ9 and HSCL compared to usual care. Comparing the phone therapy directly to the same treatment offered face-to-face, we find that phone CBT is significantly less costly (by USD501) and more cost-effective than face-to-face when effectiveness is measured by improvement in PHQ9 scores. Specifically, for the phone CBT group, one score reduction in PHQ9 costs USD634 less than face-to-face.

One limitation is that we observe the mental health service use of patients for only four months. Phone CBT might potentially lead to substantial savings or even cost-offset in the long-run. Additional studies with long-run service use data are needed to establish these findings.

The finding that phone-based intervention is able to improve the depressive symptoms of patients just as effectively as face-to-face by spending less is crucial for policy makers and health institutions looking to adopt cost-effective depression treatments.