Initiation of an Opioid Prescription for Chronic Musculoskeletal Pain and Associated Factors: a Retrospective Cohort Study Using the Quebec Integrated Chronic Disease Surveillance System

Chronic musculoskeletal pain (CMP) is a common indication for pain medications, however opioids are not clearly recommended for this condition. We aimed at describing the trend of opioid initiation for CMP among adults covered by the Quebec public drug insurance between 2006 and 2021 and identifying their associated factors. We performed a retrospective cohort study. Opioid naïve population with 18 years and over was defined for each fiscal year between 2006 and 2021. Clinical indication of their new opioid prescription was first identified using an adapted hierarchical algorithm of Pasricha,2018. CMP was identified using administrative data codes. His age-standardized incidence was estimated. We performed a negative binomial poisson regression to estimate the adjusted annual percentage change (APC) of this incidence and to identify associated factors. This incidence decreased from 70 to 9 per 10,000 persons between 2006 and 2021. The most important decrease was observed between 2015 and 2018: APC=-25.0% [95CI%: -27.1% to -24.3%]. The factors statistically associated with opioid initiation for CMP were being female (RR= 1.17 [95%CI: 1.15 to 1.19]), age (RR=1.39 [95%CI: 1.34 to 1.44] for ≥75 years compared to 18 to 34 years) and prescriber’s specialty (RR= 2.05 [95%CI: 2.00 to 2.09] for family physicians and RR= 2.71 [95%CI: 2.64 to 2.79] for medical specialists compared to surgeons). This study shows that opioid initiation for CMP decreased substantially between 2006 and 2021 in Quebec, and that these drugs were more frequently prescribed by medical specialists, among women and those aged >75 years.