Postoperative use of sleep aids and delirium in older adults after major surgery: A retrospective cohort study.

Background: Sleep aids are commonly prescribed to treat sleep disturbance, a modifiable risk factor for postoperative delirium in older patients. The use of melatonin receptor agonists in the postoperative period has been increasing. The comparative safety of melatonin receptor agonists, zolpidem, and temazepam remains uncertain.

Methods: This retrospective study included 22,083 patients ≥65 years old who initiated melatonin receptor agonists, zolpidem, or temazepam after major surgery in the Premier Healthcare Database 2009-2018. We performed propensity score-based overlap weighting and estimated the risk ratio (RR) and risk difference (RD) of postoperative delirium as the primary outcome and a composite of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality as secondary outcomes.

Results: The mean age of the study population was 78 (SD, 7) years and 50% were female. There was no significant difference in the risk of postoperative delirium among patients treated with melatonin receptor agonists (3.4%, reference group), zolpidem (2.9%; RR [95% CI], 0.9 [0.7-1.2]; RD [95% CI] per 100 persons, -0.3 [-1.1 to 0.6]), and temazepam (3.1%; 0.9 [0.7-1.1]; RD [95% CI] per 100 persons, -0.5 [-1.2 to 0.3]). The risks of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality were also similar among all groups.

Conclusions: Melatonin receptor agonists were not associated with a lower risk of postoperative delirium and other adverse outcomes compared with zolpidem and temazepam in older adults after major surgery.