Waiting time to surgery is correlated with an increased risk of serious adverse events during hospital stay in patients with hip-fracture: A cohort study.

BACKGROUND: Hip fractures are common in the elderly and are associated with a high adverse event and mortality rate. Time to surgery is one of the major modifiable risk factors influencing adverse outcomes in hip-fracture patients. National guidelines and recommendations have been introduced which advocate specific time frames in which surgery should be performed i.e. within 24-48h. These time constraints have been arbitrarily set without being modelled on the linear assumption i.e. that risk increases continually over time and not within specific cut-off times.

OBJECTIVES: To investigate how waiting time to surgery influenced the risk of serious adverse events in hip-fracture patients during the hospital stay and to examine how the risk increased over time.

DESIGN: An observational single cohort study Participants 576 patients (72.4% females, mean [SD] age 82 [10]) years, with a hip fracture were included in the cohort study.

METHODS: The outcomes of the study were the occurrence of serious adverse events during hospital stay, length of stay and one-year mortality. A structured medical record review was carried out to identify outcomes and mortality data was obtained from the Swedish National Death Registry. Waiting time to surgery was used as the exposure variable and age, sex, type of fracture, comorbidities using the American Society of Anaesthesiologists classification score and the presence of cognitive dysfunction were identified as confounders. A logistic regression analysis was performed to identify risk factors influencing outcomes.

RESULTS: A total of 119 patients (20.6%) suffered 397 (range 1-5) serious adverse events during hospital stay. Every 10h of waiting time to surgery increased the risk of serious adverse events by 12% (odds ratio 1.12 [95% confidence interval 1.02-1.23]). We found no optimal cut-off times for waiting time to surgery. For every 24h of waiting time, the length of stay from surgery was increased by 0.6days (95% CI 0.1-1.1). We found no correlation between waiting time to surgery and one-year mortality.

CONCLUSIONS: A large proportion of patients suffered from at least one serious adverse event after hip-fracture surgery and there are no safe limits for waiting time to surgery for hip-fracture patients. As the risk increases with every hour of waiting time, patients with higher American Society of Anesthesiologists classification scores, males and those with subtrochanteric fractures should be prioritized for surgery.