Association of delay of urgent or emergency surgery with mortality and use of health care resources: a propensity score-matched observational cohort study

Abstract

Background: Delay of surgery for hip fracture is associated with increased risk of morbidity and mortality, but the effects of surgical delays on mortality and resource use in the context of other emergency surgeries is poorly described. Our objective was to measure the independent association between delay of emergency surgery and in-hospital mortality, length of stay and costs.

Methods: We identified all adult patients who underwent emergency noncardiac surgery between January 2012 and October 2014 at a single tertiary care centre. Delay of surgery was defined as the time from surgical booking to operating room entry exceeding institutionally defined acceptable wait times, based on a standardized 5-level priority system that accounted for surgery type and indication. Patients with delayed surgery were matched to those without delay using propensity scores derived from variables that accounted for details of admission and the hospital stay, patient characteristics, physiologic instability, and surgical urgency and risk.

Results: Of 15 160 patients, 2820 (18.6%) experienced a delay. The mortality rates were 4.9% (138/2820) for those with delay and 3.2% (391/12 340) for those without delay (odds ratio [OR] 1.59, 95% confidence interval [CI] 1.30-1.93). Within the propensity-matched cohort, delay was significantly associated with mortality (OR 1.56, 95% CI 1.18-2.06), increased length of stay (incident rate ratio 1.07, 95% CI 1.01-1.11) and higher total costs (incident rate ratio 1.06, 95% CI 1.01-1.11).

Interpretation: Delayed operating room access for emergency surgery was associated with increased risk of inhospital mortality, longer length of stay and higher costs. System issues appeared to underlie most delays and must be addressed to improve the outcomes of emergency surgery.

Figure 1:

Study flow diagram.

Figure 2:

Spline of risk of in-hospital death as a function of wait time. The adjusted regression spline presents the proportion of acceptable wait time experienced by emergency surgical patients as a function of the odds of in-hospital death. Where the spline and 95% confidence limits are greater than the green line at 1, there is a significantly increased risk of death. CI = confidence interval.