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

Abstract

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.

LAY ABSTRACT
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 use of opioid treatments in Swedish patients with chronic non-cancer pain is unknown. Hence, the current study aimed to assess the frequency of opioid use in a population with complex chronic non-cancer pain. The study population comprised 1,613 patients referred to a Swedish specialized pain rehabilitation unit during 2015–17. Data for 1 year prior to assessment were extracted from the Swedish Quality Registry for Pain Rehabilitation and Swedish Prescribed Drug Register. Milligram morphine equivalents per day for dispensed opioids were analysed for short-term prevalence and long-term opioid therapy. In conclusion, the 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.