Costs associated with delirium among older patients undergoing complex spine surgeries

As the number of older adults undergoing spine surgery grows, it is important to better understand the risks of this procedure, including associated costs. The authors recently reported that undergoing more complex spine surgeries is strongly associated with postoperative delirium (POD). The goal of this study was to examine the costs associated with POD among patients undergoing spine surgeries of varying complexity.

Data from a prospective observational cohort study of 256 adults aged ≥ 65 years who underwent spine surgery were analyzed. Preoperative, intraoperative, and postoperative variables were collected. The primary outcome of POD was defined as a positive score on any of three measures (Confusion Assessment Method for the Intensive Care Unit, Nursing Delirium Screening Scale, and chart review). The authors conducted univariable and multivariable analyses to examine factors associated with POD and estimated costs of POD stratified by tier of surgery.

Risk factors associated with POD included age, lower education level, baseline cognitive impairment, American Society of Anesthesiologists class ≥ III, tier 4 surgery, high estimated blood loss, intensive care unit admission, postoperative complications, and hospital length of stay. In multivariable analyses, age, baseline cognitive impairment, postoperative complications, and length of hospitalization remained significantly associated with POD. The mean total costs were significantly higher in the group with delirium versus without delirium ($99,543 vs $67,892). Additionally, more patients who developed delirium required discharge to an acute rehabilitation facility (47.0% vs 21.5%, p < 0.001). In analyses stratified by tier of surgery, the greatest difference in mean costs between those with delirium versus without delirium was observed in tier 4 ($164,902 vs $116,579, p < 0.001).

Spine surgeries with greater complexity are associated with an increased risk of POD, with higher costs and rates of intensive care unit admissions, more postoperative complications, and discharge to acute rehabilitation facilities. Delirium prevention interventions targeted to older adults at high risk for POD have the potential to optimize outcomes and decrease healthcare costs.