The association between surgical start time and spine surgery outcomes

Objective: Neurosurgical operations, including spine surgeries, often occur outside "normal business hours" due to the urgent or emergent nature of cases. This study investigates the association of surgical start time (SST) with spine surgery outcomes. Methods: A retrospective cross-sectional study was performed using electronic health record data from a multihospital academic health system from 2017 to 2024. Eligible patients included adults who underwent spine surgery with a recorded SST. Patients were separated into a regular hours group (7:00 A.M. to 5:00 P.M.) and an afterhours group (SST outside this time window). The association between SST and extended length of stay (greater than 3 days), readmission, and discharge disposition was examined. Results: The sample included 12,658 patients with 10,737 (84.8 %) patients in the regular hours group and 1921 (15.2 %) patients in the afterhours group. Afterhours SST had significantly increased rates of extended length of stay, non-home discharge disposition, and readmission compared to regular hours SST. Adjusting for age, comorbidities, case classification, the time from admission to SST, and surgery type, afterhours SST was significantly associated with non-home discharge disposition (OR 1.27, 95 % CI 1.12 - 1.45, p < 0.001). Conclusion: This is the largest study to examine the association of SST with outcomes of spine surgery. Controlling for potential confounders, afterhours SST was significantly associated with non-home discharge disposition.