Behavioral pain interventions improve sleep via reduced pain interference and catastrophizing: Secondary longitudinal mediation analysis.

Sleep and pain problems commonly co-occur yet few treatments address both. Behavioral pain interventions can improve sleep even when sleep is not explicitly targeted, but how these effects occur remains unclear. We conducted a secondary analysis of a 3-arm randomized trial (N = 223) of 8-session cognitive behavioral therapy (CBT; n = 76), 1-session Empowered Relief (ER; n = 78), 1-session health education (HE; n = 69) in chronic low back pain. We tested whether changes in pain intensity, interference, catastrophizing, and self-efficacy explain sleep improvement using self-report measures from baseline, 1, 2, and 3 months. Latent growth curve mediation models were used to estimate indirect effects (CBT or ER vs. no-skills → mediator → sleep). Preliminary mediation analyses showed similar indirect effects for CBT and ER; thus, both were pooled into a skills-based treatment group and compared with the no-skills HE for primary analyses. Reductions in pain interference and catastrophizing, but not pain intensity, were associated with significant indirect pathways to improved sleep disturbance, whereas improvements in pain self-efficacy contributed a partial indirect pathway. These findings suggest that improving pain interference and pain-related cognitions may explain how skills-based pain interventions improve sleep. Targeting pain interference and pain-related cognitions may yield cross-domain benefits for both sleep and pain. PERSPECTIVE: This study identifies candidate pathways through which behavioral pain interventions improve sleep despite minimal sleep-specific content. Reductions in pain interference and catastrophizing may help explain these effects, rather than reduction in pain intensity alone. Targeting functional and cognitive-emotional aspects of pain may offer meaningful benefits across sleep and pain domains.