# Primary anesthesia provider characteristics and risk factors for intraoperative medication errors: a retrospective cohort study

## TL;DR

This study finds that less experienced anesthesia providers are more likely to make medication errors during surgery, suggesting the need for better supervision and safety systems.

## Contribution

The study identifies anesthesia provider experience and team composition as significant risk factors for intraoperative medication errors.

## Key findings

- Residents and interns under attending supervision had significantly higher odds of medication errors compared to attending anesthesiologists.
- No other patient or procedural factors were statistically associated with error risk after adjustment.
- Sensitivity analyses confirmed the robustness of the findings regarding provider-level risk factors.

## Abstract

Intraoperative medication errors, although uncommon, can result in considerable patient harm. Evidence remains limited regarding anesthesia provider-level and perioperative risk factors. This study aimed to evaluate whether anesthesia provider characteristics—particularly experience level and team composition—are statistically associated with intraoperative medication errors after multivariable adjustment.

We conducted a retrospective observational study of 100,093 surgical cases managed under anesthesia at a university-affiliated tertiary hospital in Japan between August 2011 and December 2023. Data were extracted from an electronic anesthesia record system linked to institutional medical records. Medication errors were mainly identified through anesthesia provider self-reporting, supplemented by reports from operating room nurses. Predictor variables included patient characteristics, procedural details, and the main explanatory variable was anesthesia provider configuration: attending, and resident or intern under the supervision of an attending anesthesiologist. Firth’s penalized logistic regression was used to adjust for confounding variables identified via a directed acyclic graph.

Intraoperative medication errors occurred in 102 of 100,093 procedures (0.10%). Compared with attending anesthesiologists, the odds of medication error—adjusted for the familywise error rate (FWER) using the Holm–Bonferroni method—were significantly higher when care involved residents [OR 2.713; 95% CI, 1.283–6.815; P = 0.007] or interns [OR 3.272; 95% CI, 1.508–8.368; P = 0.003]. After multiplicity adjustment, no other factors—including age, American Society of Anesthesiologists Physical Status (ASA-PS) classification, and surgical urgency—were statistically associated with error risk. Sensitivity analyses confirmed the robustness of the main findings across different covariate sets.

Anesthesia provider characteristics were statistically associated with intraoperative medication error risk. These findings suggest the need for strengthened supervision, structured team roles, and systems-based safeguards in perioperative medication safety.

The online version contains supplementary material available at 10.1186/s12871-025-03539-4.