Opioid Misuse by Adults with Chronic Pain: The Impact of Illness and Medication Beliefs.

Background: Why do some adults with chronic pain misuse their prescription opioids when others do not? Based on the extended Common-Sense Model, the study evaluated whether adults' beliefs about their pain have an indirect effect on risk of opioid misuse through beliefs about opioids when controlling for depression.

Methods: The sample included 297 adult participants in the U.S. recruited from Prolific, an online crowdsourcing website. Study measures included the Illness Perception Questionnaire-Revised (IPQ-R; protective and threat-related illness beliefs about chronic pain), the Beliefs about Medicines Questionnaire-Specific subscale (BMQ-Specific; concern and necessity medication beliefs about prescription opioids), and the Current Opioid Misuse Measure (COMM; risk of current opioid misuse). This cross-sectional parallel mediation analysis was conducted using MPlus.

Results: After controlling for depression, the indirect effect of protective illness beliefs on opioid misuse risk through concern medication beliefs (b = -0.01, 95% CI (-0. 038, -0.001), and the indirect effect of threat-related illness beliefs on opioid misuse risk through necessity medication beliefs (b = 0.02, 95% CI (0.004, 0.036) were significant. The full model explained 35% of the variance of opioid misuse risk.

Conclusions: Adults with chronic pain with stronger protective beliefs about pain were less likely to have concerns about their opioids and were at lower risk for opioid misuse, while those with greater threat-related beliefs about pain were more likely to believe that their opioids were necessary and be at greater risk for opioid misuse. Results have implications for medical and mental health providers and future research.