Objective: Major depression is expected to become the second leading contributor to disease burden worldwide by 2020. Only a few studies, however, have compared the cost-effectiveness of a combination of cognitive behavioural therapy and antidepressant therapy versus antidepressant therapy alone. The purpose of the present study was therefore to analyse cost-effectiveness, from the perspective of the health-care system and also from a social perspective, comparing combined cognitive behavioural therapy + antidepressant therapy and antidepressant therapy alone in the Japanese setting.
Method: A formal decision analytical model was constructed. The analyses were performed from both the perspective of the health-care system and the societal perspective. The clinical outcomes were determined from published articles and reports of expert panels. Because no patient-level data were available, deterministic costing of the different treatment strategies was carried out. Cost-effectiveness was assessed first by determining the incremental cost-effectiveness ratio (ICER) per successfully treated patient, and then by the ICER per quality-adjusted life years (QALYs).
Results: The combined therapy increased the rate of successfully treated patients, QALY of severe depression and QALY of moderate depression by 0.15, 0.08 and 0.04, respectively. The combined therapy proved to be more expensive from the health-care system perspective, but the incremental costs were completely offset by the considerable reduction of productivity loss from the social perspective. From the health-care perspective, the ICER per successfully treated patient, ICER per QALY of severe depression and ICER per QALY of moderate depression were JPY 140,418, JPY 268,550 and JPY 537,100, respectively. All the ICERs appeared to be negative from the social perspective.
Conclusion: The combined therapy appeared to be cost-effective from the health-care system perspective and the dominant strategy from the social perspective.