Objective: The Improving Mood-Promoting Access to Collaborative Treatment (IMPACT) trial [randomized controlled trial (RCT)] found that collaborative care management of depression in older primary care patients was significantly more effective than the usual care. We examined how an adapted version of IMPACT is working in the "real-world" setting of an HMO 3 years after the conclusion of the trial.
Method: Two hundred ninety-seven adults treated according to IMPACT protocol "poststudy" (PS) at a large group model HMO were compared to the 141 participants (historical control) in the intervention arm of the RCT at the same site. The Patient Health Questionnaire (PHQ-9) was used to compare depression severity at baseline and 6 months. We also compared treatment contacts, use of antidepressants and psychotherapy and total health care costs.
Results: The RCT and PS groups were equivalent regarding baseline depression scores (14.5 vs. 14.2, P=.72), 6-month scores (5.6 vs. 6.3, P=.28) and percent experiencing 50% improvement in depression (68% vs. 70%, P=.83). Antidepressant use was similar (85% and 90%, P=.57). Treatment contacts were fewer in PS than RCT (14 vs. 20, P<.001).
Conclusions: An adapted version of the IMPACT program implemented at a large HMO achieved similar clinical improvements in depression as the clinical trial despite a lower number of intervention contacts.