The influence of time-to-surgery on mortality after a hip fracture

The effect of time-to-surgery on mortality in acute hip fracture (AHF) patients has been debated and studies are inconsistent regarding from what time limit mortality starts to increase. At Sahlgrenska University Hospital/Mölndal, surgery is recommended within 24 hours leaving little time for pre-operative optimization. However, internationally the definition of early surgery varies between 24 and 48 hours and over. This retrospective study was initiated to investigate the relation between time-to-surgery and 30-day mortality.

Data of AHF patients from January 2007 through December 2016 were collected. The variables analysed were: age, gender, American Society of Anesthesiologists physical status classification, surgical method (prosthesis or osteosynthesis) and time-to-surgery, along with 30-day mortality. Primary outcome was 30-day mortality related to time-to-surgery divided into groups. Secondary outcome was 30-day mortality related to time-to-surgery analysed hour-by-hour.

From 10,844 eligible patients, 9,270 patients were included into the study. Mean time-to-surgery was 19.4 hours and overall 30-day mortality was 7.6%. Adjusted Cox regression analysis revealed an increased mortality rate in patients with time-to-surgery >48 hours. In the hour-by-hour analysis, significant mortality increase was observed at 39 hours of time-to-surgery. Patients with time-to-surgery >24 hours did not have increased mortality compared to patients with time-to-surgery <24 hours.

In AHF patients, a time-to-surgery exceeding 39-48 hours was associated with increased mortality. Patients with surgeries performed before 39-48 hours did not have increased mortality and this time may, in some patients, be used for optimization prior surgery even if time-to-surgery exceeds 24 hours.