Time to Remission for Depression with Collaborative Care Management (CCM) in Primary Care

Collaborative care management (CCM) has been shown to have superior outcomes to usual care (UC) for depressed patients with a fixed end point. This study was a survival analysis over time comparing CCM with UC using remission (9-item Patient Health Questionnaire [PHQ-9] score <5) and persistent depressive symptoms (PDSs; PHQ-9 score ≥10) as end points.

A retrospective cohort study of 7340 patients with depression cared for at 4 outpatient primary care clinics was conducted from March 2008 through June 2013. All adult patients diagnosed with depression (International Classification of Diseases, 9th Revision [ICD-9], codes 296.2-3) or dysthymia (ICD-9 code 300.4) with an initial PHQ-9 score ≥10 were included. CCM was implemented at all clinics between 2008 and 2010. Kaplan-Meyer survival curves for time to remission and PDSs were plotted. A Cox proportional hazards model was used to adjust for expected differences between patients choosing CCM versus UC.

Median time to remission was 86 days (95% confidence interval [CI], 81-91 days) for the CCM group versus 614 days (95% CI, 565-692 days) for the UC group. Likewise, median duration of PDSs was 31 days (95% CI, 30-33 days) for the CCM group versus 154 days (95% CI, 138-182 days) for the UC group. In the Cox proportional hazards model, which controlled for covariates such as age, sex, race, diagnosis, and initial PHQ-9 score, CCM was associated with faster remission (hazard ratio of the CCM group [HRCCM], 2.48; 95% CI, 2.31-2.65).

This study demonstrated that patients enrolled in CCM have a faster rate of remission and a shorter duration of PDSs than patients choosing UC.