Evaluation of a behavioural intervention to reduce perioperative midazolam administration to older adults

Older patients commonly receive benzodiazepines during anaesthesia despite guidelines recommending avoidance. Interventions to reduce perioperative benzodiazepine use are not well studied. We hypothesized an automated electronic medical record alert targeting anaesthesia providers would reduce administration of benzodiazepines to older adults undergoing general anaesthesia.

We conducted a retrospective study of adults who underwent surgery at 5 hospitals within one US academic health system. One of the hospitals received an intervention consisting of provider education and an automated electronic medical record alert discouraging benzodiazepine administration to patients aged 70 years or older. We used difference-in-differences analysis to compare patterns of midazolam use 12-months before and after intervention at the intervention hospital, using the 4 non-intervention hospitals as contemporaneous comparators.

The primary analysis sample included 20,347 cases among patients aged 70 and older. At the intervention hospital, midazolam was administered in 454/4,240 (10.7%) cases pre-alert versus 250/3,750 (6.7%) post-alert (p<0.001). At comparator hospitals, respective rates were 3,186/6,366 (50.0%) versus 2,935/5,991 (49.0%) (p=0.24). After adjustment, the intervention was associated with a 3.2 percentage point (p.p.) reduction in the percentage of cases with midazolam administration (95% CI: (-5.2, -1.1); p=0.002). Midazolam dose was unaffected (adjusted mean difference -0.01 mg, 95% CI: (-0.20, 0.18); p=0.90). In 76,735 cases among patients aged 18-69, the percentage of cases with midazolam administration decreased by 6.9 p. p. (95% CI: (-8.0, -5.7); p<0.001).

Provider-facing alerts in the intraoperative electronic medical record, coupled with education, can reduce midazolam administration to older patients presenting for surgery but may affect care of younger patients.