Mortality effects of timing alternatives for hip fracture surgery

BACKGROUND: The appropriate timing of hip fracture surgery remains a matter of debate. We sought to estimate the effect of changes in timing policy and the proportion of deaths attributable to surgical delay.

METHODS: We obtained discharge abstracts from the Canadian Institute for Health Information for hip fracture surgery in Canada (excluding Quebec) between 2004 and 2012. We estimated the expected population-average risks of inpatient death within 30 days if patients were surgically treated on day of admission, inpatient day 2, day 3 or after day 3. We weighted observations with the inverse propensity score of surgical timing according to confounders selected from a causal diagram.

RESULTS: Of 139 119 medically stable patients with hip fracture who were aged 65 years or older, 32 120 (23.1%) underwent surgery on admission day, 60 505 (43.5%) on inpatient day 2, 29 236 (21.0%) on day 3 and 17 258 (12.4%) after day 3. Cumulative 30-day in-hospital mortality was 4.9% among patients who were surgically treated on admission day, increasing to 6.9% for surgery done after day 3. We projected an additional 10.9 (95% confidence interval [CI] 6.8 to 15.1) deaths per 1000 surgeries if all surgeries were done after inpatient day 3 instead of admission day. The attributable proportion of deaths for delays beyond inpatient day 2 was 16.5% (95% CI 12.0% to 21.0%).

INTERPRETATION: Surgery on admission day or the following day was estimated to reduce postoperative mortality among medically stable patients with hip fracture. Hospitals should expedite operating room access for patients whose surgery has already been delayed for nonmedical reasons.

In Canada, hospitals admit 30 000 older adults with hip fracture annually.1 These patients face an increased risk of death, with up to 5% of women and 10% of men dying within 30 days.2,3 It is generally accepted that early operative intervention improves survival by reducing patients’ exposure to immobilization and inflammation.4 In 2005, the federal, provincial and territorial governments established a benchmark of 48 hours from admission for 90% of hip fracture surgeries to prevent potentially harmful delays.5 However, delays to hip fracture surgery remain common.6 Patients who are medically stable at presentation may have to wait until a surgeon or an operating room becomes available.7,8

There has been considerable debate about the point at which delaying hip fracture surgery for nonmedical reasons worsens mortality.9–25 This uncertainty leads to prioritization without benefit to the patient or underuse of expeditious surgery that could prevent deaths. Some have argued that understanding the effects of policy change should guide reorganization of operating room resources26 and prioritization in the presence of competing demand.7,27–29 In this paper, we offer 2 new estimates: the effect of possible changes in surgical timing policy in the same population of patients, and the proportion of in-hospital deaths attributable to surgical delays.