Trends in Postoperative Opioid Use in Norway 2011-2018: A Nationwide Registry-Based Study

Little is known about the overall trends in postoperative opioid use in a Nordic setting. We investigated the trends in Norway between 2011 and 2018. We linked the Norwegian Prescription Database, the Norwegian Patient Registry, the Cancer Registry of Norway and the Cause of Death Registry. Postoperative opioid use was defined as the first opioid dispensing per year within 14 days of a NOMESCO Classification of Surgical Procedure code. We excluded patients with cancer or opioid maintenance therapy. We calculated period prevalence (Norwegian population ≥ 15 years as the denominator), substance distribution, initial amount and proportion of long-acting formulations. Among 746 435 postoperative opioid users ≥ 15 years, the period prevalence increased from 27.0/1000 in 2011 to 30.0/1000 in 2018 (long-term use: 2.0 to 3.3/1000). Codeine was most frequent (67%) in 2011, while codeine and tramadol were equally dispensed (41% and 43%) in 2018; oxycodone increased from 3% to 12%. The initial amount increased for opioids as a group but declined for oxycodone (1236 morphine milligram equivalents [MME]/patient to 914 MME/patient) and tramadol (233 MME/patient to 219 MME/patient). Long-acting depot formulations increased from 5% to 12%. Over time, postoperative opioid use increased, with a shift toward more tramadol and oxycodone in lower initial amounts, and increased use of long-acting formulations.