Abstract
PURPOSE: The current study aims to investigate the possible independent association between 30-day mortality rate and the length of waiting time in older people who underwent underwent surgery for hip fractures. METHODS: This is a retrospective cohort study. Data were collected from 818 individuals aged 65 years and above who underwent surgery for hip fractures between January 2017 and July 2022 at the Affiliated Kunshan Hospital of Jiangsu University. The exposure variable was the length of waiting time, while the outcome variable was the 30-day mortality rate following hip fracture surgery. Potential covariates were analyzed including month of admission to hospital, week of admission to hospital, hip fracture category, body mass index (BMI), American Society of Anesthesiologists (ASA) score, age, surgery, gender, operation time and laboratory data. The association was finally analyzed using logistic regression models. RESULTS: Our findings revealed a positive association between 30-day mortality rate and waiting time in older people who underwent surgery for hip fractures. The obtained results showed an increase in the 30-day mortality by 13.6% (OR, 1.136; 95% CI, 1.027 to 1.256; P-value = 0.0136) when there was an addition of 10 h of waiting time after the adjustment of the covariates. The results showed a nonlinear relationship of the 30-day mortality and waiting time, while the inflection point for the waiting time in the smoothed curve was observed at 42. 428 h. Furthermore, when waiting time was < 42. 428 h, we did not detect an increase in the probability of 30-day mortality. However, a waiting time of more than 42. 428 h may increase the risk of 30-day mortality. CONCLUSIONS: Our study provides evidence of a clear positive association between waiting time before hip fracture surgery and 30-day mortality risk in older individuals. The waiting time of 42. 428 h may represent a threshold for higher risk of mortality.