Effects of biopsychosocial complexity and pain-related factors on opioid prescription in patients with chronic musculoskeletal pain.

Opioid prescription is associated with various biopsychosocial (BPS) domains. Explaining how they interact is worth to better understand their role. To assess direct and indirect effects of BPS complexity and pain-related factors on opioid prescription in patients with chronic musculoskeletal pain. We included 3,923 individuals admitted to a tertiary care rehabilitation clinic. Two outcomes were defined: likelihood of opioid prescription at admission (yes/no) and daily morphine equivalent dose (dMED) during rehabilitation. Predictors were sociodemographic factors, injury severity and location, pain-related factors (pain catastrophizing, depressive symptoms, pain severity), and BPS complexity assessed by the INTERMED method. Structural equation modelling was used to assess the direct and indirect effects of BPS complexity on outcomes. Biopsychosocial complexity had a direct effect on opioid prescription (OR 1.20; 95% CI 1.10-1.32) and indirect effects via pain severity (OR 1.09; 95% CI 1.06-1.12) and depressive symptoms (OR 1.02; 95% CI 1.00-1.04). Biopsychosocial complexity also had direct effect on dMED (β = 1.17, 95% CI 1.06-1.28) and an indirect effect via pain severity (exp β = 1.03; 95% CI 1.00-1.07). Pain catastrophizing was indirectly associated with opioid prescription and dose via pain. The likelihood of opioid prescription was associated with female sex, increased education level, and spine trauma; the latter 2 factors were also associated with increased dMED. Our study suggests that BPS complexity is associated with opioid prescription and dose, with direct and indirect effects via pain severity or depressive symptoms. Screening and addressing patients' complexity may help decrease opioid prescriptions and risk of misuse.