Abstract Introduction Daily fluctuations in sleep disturbances have been shown to shape pain experiences among individuals with chronic pain. Additional biobehavioral factors, such as abuse history, depression, current and long-term anxiety, opioid use, physical functioning, and fatigue, may also affect daily pain outcomes. Yet the extent to which these factors collectively contribute to daily pain intensity and unpleasantness remains insufficiently understood. Methods Using baseline data from the SPINII randomized controlled trial (R01NR017168; McCrae, PI), women with insomnia and fibromyalgia (N = 294, x- age = 40) completed 14 days of sleep diaries assessing sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and pain intensity and unpleasantness (0–100). Additional predictors included abuse history, Beck Depression Inventory (BDI), State–Trait Anxiety Inventory (STAI), and PROMIS-57 physical functioning and social functioning. Linear mixed models examined the effects of sleep and related factors on daily pain. Results Significant predictors of pain intensity included higher between-person SOL (b = 0.08, p .001) and WASO (b = 0.08, p .001), lower between-person TST (b = -0.10, p .001), lower within-person TST (b = −0.03, p .001), opioid use (b = 2.84, p = .029), poorer physical functioning (b = −0.35, p = .008), and higher depression scores (b = 0.20, p = .046). Pain unpleasantness showed nearly identical patterns, with only physical functioning becoming non-significant. Random intercepts and residual variance values were significant in both models (p .001), indicating within- and between-person variation in pain. ICCs of .80-.85 revealed that the majority of variance was between-person, while non-significant autocorrelations (p .05) indicated minimal day-to-day carryover effects beyond stable individual differences. Conclusion Overall sleep quality and emotional health shape pain experience more strongly than daily fluctuations. Although TST offers some next-day relief, chronic contributors are more relevant to daily pain. Effects were largely consistent; between- and within-person TST showed strong effects, and depression had a slightly larger effect on pain unpleasantness than pain sensitivity, reinforcing a multidimensional biopsychosocial pain process. These findings highlight the need for integrated interventions that strengthen sleep, emotional well-being, and physical functioning. Support (if any) NIDA
Holland et al. (Fri,) studied this question.