Risk factors for protracted postoperative length of stay after lower extremity bypass for critical limb ischemia

Abstract

Background: Compared with other common chronic conditions, admissions for management of peripheral arterial disease (PAD) are associated with prolonged hospitalizations. Length of stay (LOS) is one of many metrics receiving increased attention in the current focus on efficient healthcare delivery. Our objective was to characterize LOS among patients with severe PAD, those undergoing surgical bypass for critical limb ischemia (CLI), and identify risk factors for protracted postoperative LOS.

Methods: Patient data from the 2007 to 2009 American College of Surgeons National Surgical Quality Improvement Program were used to develop a database consisting of patients undergoing bypass surgery for CLI (n = 4,894). Protracted postoperative LOS was defined as the top quartile of days hospitalized from surgery to discharge. Preoperative risk factors with significant association (Pearson chi-squared test; P < 0.05) were used to develop a logistic regression model for protracted postoperative LOS.

Results: Average postoperative LOS was 7.5 days (median 6 days). The top quartile of postoperative LOS, >8 days, was used to define protracted LOS. Independent preoperative risk factors for protracted postoperative LOS included demographic characteristics (advanced age and non-Caucasian race), comorbidities, and medical history (e.g., obesity, dialysis dependence, severe cardiac and pulmonary disease, and bleeding disorders). Indicators of PAD severity (e.g., distal target sites, open wounds or gangrene, and prior arterial surgery) were also independent predictors of protracted LOS after surgery. The greatest predictors of extended postoperative LOS were prolonged preoperative hospitalization (OR 2.2 [95% CI: 1.8-2.6], P < 0.001) and preoperative dependent functional status (OR 2.0 [95% CI: 1.7-2.3], P < 0.001 for partial dependence; OR 2.8 [95% CI: 1.8-4.3], P < 0.001 for totally dependent status), where OR and CI stand for odds ratio and confidence interval.

Conclusions: Here, we identify preoperative risk factors for protracted postoperative LOS after infrainguinal bypass for CLI. These findings provide an important evidence basis for ongoing efforts to reduce healthcare spending and facilitate provision of efficient health care. Future efforts will include prospective identification of patients at high risk for protracted postoperative LOS and targeted multidisciplinary efforts to reduce associated costs without sacrificing healthcare quality.