Fatigue and Sleep-related Impairment as Predictors of the Effect of Nonpharmacological Therapies for Active duty Service Members With Chronic Pain: A Secondary Analysis of a Pragmatic Randomized Clinical Trial.

Introduction: First-line treatments for chronic pain include selected complementary and integrative health therapies, including spinal manipulation, acupuncture, yoga, and massage; and standard rehabilitative care, including physical and occupational therapies. This study aimed to uncover critical factors that contribute to pain impact and the effectiveness of complementary and integrative health therapies and standard rehabilitative care among people with chronic pain, with a focus on the role of sleep-related impairment.

Materials and methods: We conducted a secondary analysis of data from a pragmatic randomized clinical trial of 280 U.S. active duty service members with chronic pain.

Results: Our study's multiple mediation analysis examined the indirect effect of complementary and integrative health therapies on pain impact through fatigue (β = - 0.43; 95% CI, -0.99 to -0.07). When stratified by sleep-related impairment, participants with T scores above the median of 62 demonstrated a significant negative indirect effect of complementary and integrative health therapies through fatigue (β = - 0.80; 95% CI, -2.31 to -0.14). This negative indirect effect was not significant for participants with sleep-related impairment T scores below the median (β = - 0.64; 95% CI, -1.48 to 0.07).

Conclusion: These findings suggest that complementary and integrative health therapies are particularly effective in reducing pain impact for individuals with higher levels of sleep-related impairment, and that the effect of complementary and integrative health therapies is supported primarily by reducing fatigue.