Variation in the effectiveness of collaborative care for depression: Does it matter where you get your care?

Randomized controlled trials have demonstrated that the collaborative care model for depression in primary care is more effective than usual care, but little is known about the effectiveness of this approach in real-world settings. We used patient-reported outcome data from 11,303 patients receiving collaborative care for depression in 135 primary care clinics to examine variations in depression outcomes. The average treatment response across this large sample of clinics was substantially lower than response rates reported in randomized controlled trials, and substantial outcome variation was observed. Patient factors such as initial depression severity, clinic factors such as the number of years of collaborative care practice, and the degree of implementation support received were associated with depression outcomes at follow-up. Our findings suggest that the level of implementation support could be an important influence on the effectiveness of collaborative care model programs.