Objective: To determine the incremental cost-effectiveness of a quality improvement depression intervention (enhanced care) in primary care settings relative to usual care.
Design: Following stratification, we randomized 12 primary care practices to enhanced or usual care conditions and followed patients for 12 months.
Setting: Primary care practices located in 10 states across the United States.
Patients/participants: Two hundred eleven patients beginning a new treatment episode for major depression.
Interventions: Training the primary care team to assess, educate, and monitor depressed patients during the acute and continuation stages of their depression treatment episode over 1 year.
Measurements and main results: Cost-effectiveness was measured by calculating incremental (enhanced minus usual care) costs and quality-adjusted life years (QALYs) derived from SF-36 data. The mean incremental cost-effectiveness ratio in the main analysis was US dollars 15463 per QALY. The mean incremental cost-effectiveness ratios for the sensitivity analyses ranged from US dollars 11341 (using geographic block variables to control for pre-intervention service utilization) to US dollars 19976 (increasing the cost estimates by 50%) per QALY.
Conclusions: This quality improvement depression intervention was cost-effective relative to usual care compared to cost-effectiveness ratios for common primary care interventions and commonly cited cost-effectiveness ratio thresholds for intervention implementation.