Factors Predicting Length of Hospital Stay and Extended Care Facility Admission After Hindfoot Arthrodesis Procedures

Abstract

Delayed identification of patients requiring admission to extended care facilities (ECFs) can lead to greater healthcare costs through an increased length of hospital stay (LOHS). Previous studies of hip and knee arthroplasty identified factors associated with a likely discharge to an ECF. These issues have not been extensively studied for major hindfoot procedures. We conducted a retrospective review of 198 cases treated during a 3-year period to identify the risk factors for an extended LOHS and ECF admission after ankle arthrodesis, triple arthrodesis, pantalar arthrodesis, and subtalar arthrodesis. The primary outcomes were LOHS and ECF admission. The independent predictors included age, sex, body mass index, housing status, American Society of Anesthesiologists class, diabetes and/or diabetic neuropathy, health insurance, fixation type, and perioperative infection. Stepwise multiple regression analysis was used to determine which variables were related to a longer LOHS. Nonparametric discriminant function analysis was used to identify the preoperative factors that best predicted ECF admission. A longer LOHS was significantly related to postoperative ECF admission, Centers for Medicare and Medicaid Services (CMS) insurance, diabetic neuropathy, external fixation, and infection. ECF admission was required for 34 of 198 patients (17.2%). Discriminant analysis found that older age, living alone, external fixation, and CMS insurance predicted a greater probability of ECF admission. The function accurately classified 94% of ECF admissions and 80% of non-ECF admission patients. ECF admission and CMS insurance extended the LOHS, likely owing to the administrative process of arranging an ECF discharge. If externally validated, the function we have derived could provide preoperative identification of likely ECF discharge candidates and reduce costs by shortening the LOHS.