Persistence with opioids post discharge from hospitalisation for surgery in Australian adults: a retrospective cohort study.

Objective: To determine time to opioid cessation post discharge from hospital in persons who had been admitted to hospital for a surgical procedure and were previously naïve to opioids.

Design, Setting And Participants: Retrospective cohort study using administrative health claims database from the Australian Government Department of Veterans' Affairs (DVA). DVA gold card holders aged between 18 and 100 years who were admitted to hospital for a surgical admission between 1 January 2014 and 30 December 2015 and naïve to opioid therapy prior to admission were included in the study. Gold card holders are eligible for all health services that DVA funds.

Main Outcome Measures: The outcome of interest was time to cessation of opioids, with follow-up occurring over 12 months. Cessation was defined as a period without an opioid prescription that was equivalent to three times the estimated supply duration. The proportion who became chronic opioid users was defined as those who continued taking opioids for greater than 90 days post discharge. Cumulative incidence function with death as a competing event was used to determine time to cessation of opioids post discharge.

Results: In 2014-2015, 24 854 persons were admitted for a surgical admission. In total 3907 (15.7%) were discharged on opioids. In total 3.9% of those discharged on opioids became chronic users of opioids. The opioid that the patients were most frequently discharged with was oxycodone; oxycodone alone accounted for 43%, while oxycodone with naloxone accounted for 8%.

Conclusions: Opioid initiation post-surgical hospital admission leads to chronic use of opioids in a small percentage of the population. However, given the frequency at which surgical procedures occur, this means that a large number of people in the population may be affected. Post-discharge assessment and follow-up of at-risk patients is important, particularly where psychosocial elements such as anxiety and catastrophising are identified.