Clinically Important Change in Insomnia Severity After Chronic Pain Rehabilitation

Abstract

Objectives: Insomnia is a common problem for people with chronic pain. It is unclear, however, whether interdisciplinary treatment centered on pain management, rather than sleep, confers a benefit in reducing insomnia symptoms. In this study, we examined clinically important change in insomnia severity following participation in an interdisciplinary chronic pain rehabilitation program.

Methods: A total of 140 patients (43 men and 97 women) completed a 4-week outpatient day program for interdisciplinary rehabilitation that incorporated psychoeducation about pain, physical fitness, and group psychotherapy. The Insomnia Severity Index (ISI) was included as an outcome, along with measures of pain, mood, and function.

Results: On the ISI before treatment, 20 patients (14.3%) reported no insomnia, 36 (25.7%) had a mild or subthreshold problem, and 84 (60%) had moderate (31.4%) or severe (28.6%) clinical insomnia. After treatment, ISI scores showed a statistically significant improvement overall (P<0.001). Six indices of individual change were examined among those with moderate-severe insomnia at baseline. Depending on the index used, rates of clinically important improvement ranged from 2.4% to 47.6%; however, only 2 patients with insomnia met criteria for full remission. Among patients with no or subthreshold symptoms at baseline, from 0% to 14.3% were worse after treatment, depending on the criterion.

Discussion: Insomnia improves overall following interdisciplinary rehabilitation for chronic pain, but most patients with clinical insomnia continue to have a significant sleep problem after treatment, and some patients may get worse. Interventions to alleviate persistent insomnia comorbid with chronic pain are likely to require a more intensive focus on sleep itself.