Introduction: Prolonged length of stay (LOS) after surgery is associated with increased health care costs. Accurate prediction of LOS following elective lumbar fusion may help optimize the utilization of resources, and assist with framing physician and patient expectations. This study aims to elucidate preoperative and perioperative variables that are predictive of prolonged LOS.
Methods: This is a post-hoc analysis of a prospective randomized controlled trial comparing the efficacy of intrathecal morphine versus placebo for postoperative pain following elective lumbar fusion. The primary outcome was prolonged LOS defined as >5 days. Preoperative variables including patient age, sex, BMI, Oswestry Disability Index (ODI), and visual analogue scale (VAS) for pain were collected. Perioperative variables including number of level fused, length of operation time (prolonged surgery defined as >265min) and presence of perioperative adverse events were recorded. ODI and VAS were dichotomized to severe disability (ODI score >40) and severe pain (VAS>70mm).
Results: 150 patients underwent elective lumbar fusion surgery. The mean age was 62.0 years old (SD: 12.0) and 64 (42.7%) were male. The mean preoperative ODI and VAS for pain was 37.6 (SD: 13.6) and 54.3mm (SD: 22.0) respectively. The mean LOS was 4.9 days (SD: 2.2), and 41 (39.0%) patients had LOS>5 days. Multivariable logistic regression showed age >70 years (OR 4.7 [95%CI 1.8-12.1], p=0.002), severe disability on ODI (OR 4.7 [95%CI 1.9-11.8], p=0.001), multilevel fusion (OR 3.2 [95%CI 1.3-7.9], p=0.01), and presence perioperative adverse event (OR 5.9 [95%CI 1.7-20.9], p=0.006) predicted prolonged LOS.
Conclusions: Prolonged LOS was significantly influenced by older age, severe disability, multilevel fusion, and presence perioperative adverse event. Findings from this study can be used for patient counselling and to anticipate patient trajectory after surgery.
Patient Care: In part due to the aging demography, rates of lumbar spine fusion are increasing. Prolonged length of stay (LOS) after surgery is associated with increased health care costs. The results from this study will allow improved prediction of length of stay following elective lumbar fusion, help optimize the utilization of resources, and assist with framing physician and patient expectations.
Learning Objectives: By the conclusion of this session, participants should be able to 1) describe the risk factors for prolonged length of stay following elective open lumbar fusion surgery and 2) identify preoperative severe disability as a novel predictor for prolonged length of stay.