Outcome Differences Between General and Neuraxial Anesthesia for Hip Fracture by Frailty and Age in the Elderly: A Retrospective Cohort Study.

Abstract

BACKGROUND Frailty and age are major outcome drivers in hip fracture surgery, but their interaction has not been considered in neuraxial versus general anesthesia comparisons. Using the Hospital Frailty Risk Score (HFRS), we examined this interaction. METHODS In this retrospective cohort study (2016-2023, Premier Healthcare Database), adults undergoing hip fracture surgery with neuraxial or general anesthesia were included and stratified by age quantiles (≤71, 72-86, ≥87 years) and HFRS (low, intermediate/high). The primary outcome was an in-hospital composite of mortality and major system complications. Intensive care unit (ICU) admission and high opioid use or prolonged length of stay (LOS) ≥75th percentile were also assessed. We used mixed-effects models and reported odds ratios (OR) and 95% confidence intervals (CIs). RESULTS Among 623,122 patients, neuraxial (versus general) anesthesia was associated with lower odds of the composite outcome in patients ≥87 years with intermediate/high frailty (OR, 0.88 and 95% CI, 0.83-0.94; P < .001). Overall, neuraxial anesthesia was linked to higher odds of respiratory complications (OR, 1.06 and 95% CI, 1.01-1.10; P = .03), driven by patients ≤71 years with intermediate/high frailty, and lower odds of renal failure (OR, 0.87 and 95% CI, 0.83-0.92; P < .001), primarily among those ≥72 years with intermediate/high frailty. Neuraxial anesthesia was also associated with higher cardiac complication odds (OR, 1.07 and 95% CI, 1.02-1.12; P = .008), particularly in patients aged 72 to 86 years with intermediate/high frailty. Mortality odds were lower overall (OR, 0.83 and 95% CI, 0.74-0.93; P = .003), driven by patients ≥87 years with intermediate/high frailty. Neuraxial anesthesia was associated with higher odds of prolonged LOS in patients aged 72 to 86 years with low frailty (OR, 1.16 and 95% CI, 1.04-1.31; P = .035), but lower odds in those ≥87 years with intermediate/high frailty (OR, 0.92 and 95% CI, 0.87-0.97; P = .012). It was associated with lower odds of high opioid use overall and within each subgroup. ICU admission odds were higher in patients ≤71 years with intermediate/high frailty (OR, 1.16 and 95% CI, 1.05-1.29; P = .019) but lower in those ≥87 years with intermediate/high frailty (OR, 0.82 and 95% CI, 0.75-0.90; P < .001). Neuraxial anesthesia was linked to higher odds of discharge home (OR, 1.08 and 95% CI, 1.04-1.12; P < .001), except among ≥87-year-old intermediate/high frailty patients, where odds were lower (OR, 0.90 and 95% CI, 0.81-0.99; P = .041). CONCLUSIONS Neuraxial versus general anesthesia showed modest overall benefits after hip fracture, varying by age-frailty subgroup, supporting frailty-guided anesthetic decisions clinically.Level of evidence: III. Retrospective cohort study.