https://www.selleckchem.com/products/ak-7.html The opioid overdose crisis underscores the need for health services among people who use drugs (PWUD) with concurrent pain. Investigating the effect of pain on barriers to accessing health services among PWUD. Prospective cohort study. A setting of universal access to no-cost medical care in Vancouver, Canada from June 2014 to May 2016. PWUD who completed at least one study interview. Data derived from interviewer-administered questionnaires were used for multivariable generalized linear mixed-effects multiple regression (GLMM) analyses. Among 1,348 PWUD, 469 (34.8%) reported barriers to accessing health services at least once during the study period. The median average pain severity was 3 (IQR 0-6) out of 10. A dose-response relationship was observed between greater pain and increased odds of reporting barriers to accessing health services (adjusted odds ratio [AOR] 1.59, 95% confidence interval [CI] 1.15-2.21,p = .005 for mild versus no pain; AOR 1.76, 95% CI 1.30-2.37,p < .001 for moderate versus no pain; AOR 2.55, 95% CI 1.92-3.37,p < .001 for severe versus no pain). Common barriers included poor treatment by health professionals, socio-structural barriers such as transportation or mobility, and long wait lists or wait times. Pain may be a significant risk factor associated with increased barriers to accessing health services among PWUD. Attention to pain management may improve access to health services, and reducing barriers to health services may conversely improve pain management and its related risks and harms. Pain may be a significant risk factor associated with increased barriers to accessing health services among PWUD. Attention to pain management may improve access to health services, and reducing barriers to health services may conversely improve pain management and its related risks and harms. This study aimed to explore parental attitudes toward children's pain and analgesic drugs and parental self-effic