Background: The goal of this randomized clinical trial was to examine the efficacy of a cognitive behavioral stress reduction treatment for reducing disability among veterans with chronic multisymptom illness (CMI).
Method: Veterans (N=128) who endorsed symptoms of CMI were randomized to: usual care (n=43), in-person (n=42) or telephone-delivered cognitive behavioral stress management (n=43). Assessments were conducted at baseline, three months, and twelve months. The primary outcome was limitation in roles at work and home (i.e., 'role physical'). Reductions in catastrophizing cognitions were evaluated as a mechanism of action.
Results: Intent-to-treat analyses showed no statistically significant main effect (F(2, 164)=.58, p=.56) or interaction effect (F(4,164)=.94, p=.45) for role physical. Over time, veterans improved in their physical function (F(2,170)=5.34, p<.01; ὴ2 partial=.06), PTSD symptoms (F(2,170)=9.39, p<.01; ὴ2 partial=.10), depressive symptoms (F(2,170)=10.81, p<.01, ὴ2 partial=.11), and physical symptoms (F(2, 172)=12.65, p<.01; ὴ2 partial=.13), but these improvements did not differ across study arms over time. Completer analyses yielded similar results. There were no differences in catastrophizing between arms.
Conclusion: Findings suggest stress reduction may not be the right target for improving disability among veterans with CMI. Veterans with CMI may need intervention that directly impacts medical self-management to improve disability.
Keywords: chronic multisymptom illness; clinical trial; cognitive behavioral therapy; disability; null results; stress management.