Prevalence of analgesic use in patients with chronic pain referred to a multidisciplinary pain centre and its correlation with patient-reported outcome measures: A cross-sectional, registry-based study

Chronic pain is prevalent in Sweden, nearing 20% in the adult population. Treatment often requires a multimodal approach, with medication, physical therapy and psychological interventions. However, the frequency of medication in patients with chronic pain in Sweden, and its correlation with patient-reported outcome measures (PROMs), are currently unknown. To investigate the frequency of use of analgesics and other medication in patients with chro-nic pain referred to a multidisciplinary pain centre, and how opioid treatment relates to PROMs. Cross-sectional, registry-based study. New referral visits (n = 1,275) to the Pain and Rehabilitation Center in Linköping, Sweden in 2015. 441 patients had complete medication and PROM data. Patient-reported analgesic and other medications were matched with patient PROM data from the Swedish Quality Registry for Pain Rehabilitation. Univariate analysis was conducted with IBM Statistical Package for the Social Sciences (SPSS; IBM Corporation, Somers, NY, USA) version 24.0, and multivariate analysis with SIMCA-P+ (version 13, Umetrics AB, Umeå, Sweden), with a special emphasis on opioids. n = 132 (30%) patients used opioids daily, and this group differed from other patients on many PROMs, with medium effect sizes for pain severity, interference, health-related quality of life, activity engagement, and satisfaction with social life. Multivariate analysis identified four groups and showed that daily use of opioids was significantly correlated with high pain intensity and low physical functioning. Prevalence of daily opioid use was 30% and daily opioid use did not correlate with better outcome of PROMs. Longitudinal studies are warranted (e.g. on the clinical effect of tapering), as are studies that can better explain the medication variability in patients with complex chronic pain.