0393 Baseline Pain Severity as a Moderator of the Effect of CBTi on Sleep and Pain Outcomes in Patients with Fibromyalgia

Abstract

Introduction: CBTi improves sleep and pain in patients with chronic pain, but significant pain effects are rarely found in individual trials - possibly due to floor effects as trials rarely screen for baseline pain intensity (bPI). The present study examines whether bPI moderates the effect of CBTi on sleep and pain in adults with FM. Methods: Adults (N=64, Mage=53.2, SD=13.7) with FM and chronic insomnia were randomized to 8-week CBT-I or waitlist control. Participants completed the McGill Pain Questionnaire (MPQ) and 14 daily diaries recording PI (0-none, 100-worst), SOL, WASO, TWT, and sleep quality (1-very good, 5-very poor) at baseline, post-treatment, and 6-month follow-up. Multiple regressions determined whether average bPI predicted changes in sleep (SOL, WASO, TWT, sleep quality) and pain (MPQ total score), controlling for age, sleep/pain medication, TST, and depression. Results: bPI moderated the impact of CBTi on SOL (t=2.42, p=.02) and TWT (t=2.02, p=.05). Specifically, moderate (53.32, SOL t=2.43, p=.02; TWT t=3.18, p