Objective: Collaborative care for depression decreases arthritis pain and disability among older adults, above and beyond mood improvement. This study investigates whether depression management is effective for improving arthritis outcomes across a range of pain severity and activity interference.
Methods: A multi-site randomized-controlled trial (Improving Mood, Providing Access to Collaborative Treatment - IMPACT) identified 1001 participants with both depression and arthritis (mostly osteoarthritis). Depression care managers provided 12 months of systematic depression care [antidepressant pharmacotherapy, and/or problem-solving treatment (PST)] for intervention participants in primary care settings. Control patients received care as usual. Baseline and 12-month interviews assessed arthritis pain severity and activity interference as well as depression, analgesic use, overall functional impairment and coexisting medical conditions.
Results: Baseline pain severity showed significant interactions with the intervention on 12-month pain severity (t=2.28, df=68, P=.03) and disability outcomes (t=2.03, df=177, P=.04). Interaction effects of the intervention with baseline activity interference on 12-month pain severity showed a similar trend, but were not statistically significant (t=1.87, df=944, P=.06).
Conclusions: Systematic depression management was more effective than usual care in decreasing pain severity among arthritis patients with lower initial pain severity, but did not have greater benefits than usual care on pain among patients with higher initial pain severity.