Association between time to surgery and 90-day mortality after hip fracture: A retrospective cohort study of 1734 cases.

Background: It remains unclear whether early surgical intervention can reduce mortality after surgery in hip fracture patients. The aim of this study was to investigate the association between time from injury to surgery and mortality rate within 90 days after hip fracture surgery.

Methods: We retrospectively identified 1827 patients who underwent hip fracture surgery in a tertiary care center in Japan between April 2007 and March 2017. After applying exclusion criteria (patients with spontaneous fracture, multiple fractures, revision surgery, total hip arthroplasty, or a refusal to participate), 1734 patients were included. We extracted data concerning patients' age, race, sex, operative procedure, American Society of Anesthesiologists (ASA) score, days from injury to surgery (injury-surgery days), and days from admission to surgery (admission-surgery days), which could affect 90-day mortality after surgery. Variables associated with 90-day mortality were determined using multivariate logistic regression analysis.

Results: The 90-day postoperative mortality rate was 3.5% (60 of 1734). Multivariable analysis showed that injury-surgery days were not associated with 90-day mortality (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.80 to 1.05; P = 0.19), and that older age (OR, 1.06; 95% CI, 1.02 to 1.10; P = 0.005), male sex (OR, 3.62; 95% CI, 1.86 to 7.03; P < 0.001) and high ASA score (OR, 2.10; 95% CI, 1.06 to 4.18; P = 0.034) significantly increased 90-day mortality. In addition, admission-surgery days were not associated with 90-day mortality (OR, 0.95; 95% CI, 0.83 to 1.09; P = 0.45).

Conclusion: Our results demonstrated that time from injury to surgery was not associated with mortality within 90 days after surgery after adjusting for age, sex, operative procedure, and ASA score.