Prolonged care management for depression: a case-controlled study of those enrolled for more than one year

Collaborative care management (CCM) for the treatment of depression has been shown to be an effective therapy. CCM can be seen as a resource intensive treatment. Early identification of patients who would not be effectively treated with CCM could allow for alteration of therapy or change in modality.

A retrospective case-controlled study used 132 patients with prolonged enrollment (>1 year) in CCM (cases) and 396 randomized CCM patients who achieved remission within 6 months (controls). The hypothesis was that by studying the epidemiology of patients in prolonged care management (PCM), characteristics could be determined to help define this group.

With regression modeling, the odds of a patient having PCM at 1 year was highly significant for those unmarried patients (odds ratio [OR] = 1.736, confidence interval [CI] = 1.115-2.703, P = .015) with dysthymia (OR = 2.362, CI = 1.104-5.052, P = .027) and severe depression (OR = 2.856, CI = 1.551-5.260, P = .001). The adjusted baseline Patient Health Questionnaire-9 (PHQ-9) score showed a difference of 16.0 for the cases versus 14.8 for the controls (P < .001). By 10 weeks, the difference is much larger at (10.7 vs 4.9, P < .001). At 26 weeks, the control group had an adjusted average PHQ-9 score of 2.0, whereas the case group was still elevated at 10.2 (P < .001).

Case-controlled analysis of PCM patients demonstrated independent predictors (such as unmarried status, diagnosis of dysthymia or severe depression), however, no baseline data was of sufficient clarity to suggest changes in clinical practice. The trend of the patient's PHQ-9 over time was strongly suggestive of allowing differentiation between the groups.