The relative contribution of pain and psychological factors to opioid misuse: A 6-month observational study.

There is a pressing need to better understand the factors contributing to prescription opioid misuse among patients with chronic pain. Cross-sectional studies have been conducted in this area, but longitudinal studies examining the determinants of prescription opioid misuse repeatedly over the course of opioid therapy have yet to be conducted. The main objective of this study was to examine the relative contribution of pain and psychological factors to the occurrence of opioid misuse among patients with chronic pain prescribed opioids. Of particular interest was to examine whether pain intensity and psychological factors were more strongly associated with certain types of opioid misuse behaviors. Patients with chronic pain (n = 194) prescribed long-term opioid therapy enrolled in this longitudinal observational cohort study. Patients completed baseline measures and were then followed for 6 months. Opioid misuse was assessed once a month using self-report measures, and urine toxicology screens complemented patients' reports of opioid misuse. Heightened pain intensity levels were associated with a greater likelihood of opioid misuse (p = .014). However, pain intensity was no longer significantly associated with opioid misuse when controlling for psychological factors (i.e., negative affect, catastrophizing). Subsequent analyses revealed that higher levels of catastrophizing were associated with a greater likelihood of running out of opioid medication early, even after controlling for patients' levels of pain intensity and negative affect (p = .016). Our findings provide new insights into the determinants of prescription opioid misuse and have implications for the nature of interventions that may be used to reduce specific types of opioid misuse behaviors. (PsycInfo Database Record (c) 2020 APA, all rights reserved).