Prevalence of Long-Term Opioid Therapy in a Chronic Non-Cancer Pain Population Attending a University-Based Tertiary Pain Clinic in Sweden: A Cross-Sectional Study.

Background: Opioid therapy is a common treatment for chronic pain, despite accumulating evidence regarding harm and a lack of data to support the efficacy of long-term treatment. The prevalence of opioid therapy in Swedish patients with chronic non-cancer pain is unknown. The aim of this study was to assess a short-term period prevalence of prescribed opioid-use and long-term opioid therapy in a population with complex chronic non-cancer pain.

Methods: The study population comprised 1,613 patients with chronic non-cancer pain referred to a university-based tertiary pain clinic in Sweden during 2015-17. Data from a 360-day period prior to consultation were extracted from the Swedish Quality Registry for Pain Rehabilitation (SQRP) and Swedish Prescribed Drug Register (SPDR). Milligram morphine equivalents per day (MME/day) for dispensed opioids were analysed for a 90-day period preceding consultation, and long-term opioid therapy was determined for the entire 360-day period.

Results: The 90-day prevalence was 38% (95% confidence interval (95% CI) 36.0-40.8%) and 360-day prevalence was 22.3% (n=360, 95% CI 20.4-24.4%).

Conclusion: Prescribing rates of opioids in a Swedish population with complex non-cancer chronic pain were high; 2 in 5 patients were dispensed an opioid within a 90-day period prior to consultation.