(223) Risk of post-surgical persistent opioid use and fractures in patients undergoing major surgery in England

Background: Opioids remain a cornerstone of post-surgical pain management. However, long-term use of opioids does not provide any additional analgesic benefit and may lead to unwanted harm.

Objectives: This study examined the risk of post-surgical persistent opioid use (PPOU) and fractures in patients following major surgery in England.

Methods: This retrospective cohort study used electronic health records from the Clinical Practice Research Datalink GOLD, linked with Hospital Episode Statistics from January 2000 to March 2020. Adults (aged ≥18 years) who underwent six major surgical procedures were followed from the date of the first opioid prescription in primary care within 30 days after discharge to the end of follow-up, date of death or transfer out of practice. A multi-dimension algorithm was employed in the first patient year to identify PPOU, using the ‘wide’, ‘intermediate’ and ‘strict’ criteria based on the annual dose in oral morphine equivalent dose, the annual number of quarters covered with an opioid prescription and number of opioid prescriptions received. Multivariable logistic regression was used to identify factors associated with PPOU. The incidence of severe adverse events, i.e. risk of fractures and the time to the first event, were calculated.

Results: Of the 294,519 patients who underwent major surgery, 91,528 (31%) received an opioid prescription within 30 days post-discharge. The average patient follow-up was 5.3 years (95%CI: 5.28, 5.33). The one-year prevalence of PPOU was 0.28% (95%CI: 0.25%, 0.32%), 0.04% (95%CI: 0.03%, 0.06%) and 0.01% (95%CI: 0.005%, 0.02%) post-discharge, according to the ‘wide’, ‘intermediate’ and ‘strict’ criteria. Factors significantly associated with first-year PPOU included baseline co-morbidity, pre-operative opioid use, long-acting opioid, gabapentinoid, benzodiazepine use and Z-drug use.
Patients on opioids pre-operatively or long-acting formulations had 2.69 and 5.16 times higher odds of PPOU, respectively. Patients on higher daily oral morphine equivalent doses (≥50 mg/day) were at a 5.61 increased odds of PPOU. There was an association between morphine equivalent dose category and fracture events with an incident rate ratio of 1.26 (95%CI: 1.12, 1.42). The average time to a fracture event was 56.6 months (95%CI: 52.9, 60.4).

Conclusions: Identifying factors associated with PPOU and its associated harm informs developing interventions to predict high-risk individuals and effective risk reduction strategies. Future research is needed to investigate other PPOU-related harm and associated factors further.