OP3-3 - New and persistent benzodiazepine use associated with surgery

Introduction:

The use of benzodiazepines (BZD) has increased with subsequent rising incidence of BZD-associated complications and harm. Understanding the pattern of BZD use is important. Perhaps some of new and new persistent use is among patients who begin using BZD perioperatively or following surgery. Our aim was to describe BZD dispensing patterns and determine the incidence of new and new persistent BZD use among patients undergoing surgery.

Methods:

This retrospective single-center population-based cohort study included all individuals, 18 years or older, undergoing surgery at Landspítali–The National University Hospital, Reykjavík, Iceland, in 2006 through 2018, with a year of follow-up for dispensed medications. Data for filled anxiolytic BZD (ATC class N05BA) prescriptions and the following definitions were used to determine incidence of new and new persistent BZD use. BZD-naïvety was defined as not filling any prescriptions for anxiolytic BZD (N05BA) from365 days through 31 days preceding surgery. New BZD use was defined as BZD-naïvety followed by dispensing at least 1 prescription from 30 days before through 14 days after surgery. Finally, new persistent BZD use was defined as new BZD use followed by filling at least 1 prescription from 15 days through 365 days following surgery. Additionally, the subcohorts were compared with regards to: BZD filling patterns on a continuous timescale, patient- and procedural characteristics, and outcomes. Multivariable logistic regression was used to assess variables associated with new and new persistent use of BZD. Data was analyzed from February to June 2022.

Results:

This study included 55997 patients (median [IQR] age, 55 [39, 69] years), of those 86.7% (95% CI, 86.4%-87.0%; n=48558) were BZD-naïve. New use among BZD-naïve patients was 2.7% (95% CI, 2.6%-2.8%; n=1311), of whom 43.7% (95% CI, 41.0%-46.5%; n=571) filled criteria for new persistent BZD use. Among patients with new use roughly 10% dispensed a BZD prescription within every 30-day running window during the year following surgery. Female sex, age 40-69 years, preoperative diagnosis of malignant neoplasm or anxiety, higher comorbidity (quantified by the Elixhauser comorbidity score), and preoperative use of serotonin specific reuptake inhibitors and opioids were independently associated with increased odds of new use. Major frailty risk score was associated with decreased odds. Furthermore, preoperative diagnosis of malignant neoplasm, mood disorders or anxiety and an intermediate comorbidity burden were associated with increased odds of new persistent use. Patients with new use had a longer primary hospital stay and both patients with new and new persistent use had more frequent 30-day readmissions and rate of an adverse drug event diagnosis both before and after surgery.

Conclusion:

A small proportion of patients undergoing surgery begin using BZD in the perioperative period. However, almost half subsequently go on to persistent BZD use. This indicates that short-term perioperative use serves as a potential gateway into long-term use. Therefore, it is important to identify approaches to reduce new and persistent use among surgical patients.