Vaccination is associated with reduced mortality rates after surgery for hip fractures in the setting of recent COVID-19 infection: an observational study from the Kaiser Permanente Northern California Database
DOI:
https://doi.org/10.2340/17453674.2026.45696Keywords:
COVID-19, Fractures, Hip, Hip Fracture, Mortality, Thromboembolism, VaccinationAbstract
Background and purpose: Limited data exist on mortality and venous thromboembolism (VTE) risk in hip-fracture patients with recent COVID-19 infection. We aimed to examine (i) the association between vaccination status and mortality risk, (ii) whether infection timing is associated with mortality risk, and (iii) whether recent infection is associated with an increase in postoperative VTE risk.
Methods: Adult Kaiser Permanente Northern California members undergoing hip-fracture surgery (2020–2022) were identified. Patients with varying vaccination statuses and SARS-CoV-2 infection histories within 6 months preoperatively were analyzed. Multivariable regression models were adjusted for demographics, comorbidities, and COVID-19 status to calculate risk ratios. The primary outcome was 90-day mortality; the secondary outcome was 90-day VTE.
Results: 3,674 patients were included. Unvaccinated or partially vaccinated patients with COVID-19 within 6 months preoperatively had a 4.49-fold higher 90-day mortality risk than fully vaccinated patients (95% confidence interval [CI] 3.72–5.42). Among COVID-positive patients, shortening of the interval from infection to surgery from 6 months to 6 weeks was associated with increased 90-day mortality risk of approximately 53% (CI 1.29–1.97). Additionally, more recent infection (within 6 months) was associated with a 3.14-fold higher postoperative VTE risk (CI 1.10–8.98).
Conclusion: COVID-19 vaccination is associated with a reduction in the mortality risk among hip-fracture patients with recent infection. Shorter infection-to-surgery intervals are associated with increased mortality risk, and recent infection is associated with higher VTE risk.
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Copyright (c) 2026 Aidan T Morrell, Ryland P Kagan, Mackenzie Kelly, Graham J Dekeyser, Andrew L Avins, Lusine X Gigoyan, John S Cox
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