The Influence of Modifiable, Postoperative Patient Variables on the Length of Stay After Total Hip Arthroplasty

Many studies have examined strategies to reduce length of stay (LOS) after total hip arthroplasty (THA), but few have focused on modifiable patient-specific information in the acute postoperative period. This study investigates the determinants of LOS after THA, with a focus on potentially modifiable factors.

A total of 1278 patients undergoing elective THA from 2012 to 2014 were extracted from our institutional data warehouse at our academic orthopedic specialty hospital. Data were collected on patient demographics, comorbidities, inpatient opioid use, hypotensive events, and abnormalities in laboratory values, all occurring on postoperative day 0 or 1. The main outcome was hospital LOS. Multivariate regression analysis was performed to identify independent risk factors for LOS over 3 days.

The average age of patients undergoing primary total hip arthroplasty in our cohort was 62.3 (standard deviation 10.7) years, and 52.7% were women. Eighty-one (6.3%) of 1278 patients had a LOS more than 3 days. Multivariate regression analysis demonstrated several statistically significant nonmodifiable and modifiable risk factors that influence LOS after THA. Nonmodifiable risk factors included nonwhite race (odds ratio [OR], 1.497), single marital status (OR, 1.724), increasing age (OR, 1.330), and increasing Charlson Comorbidity Index (OR, 1.411). Potentially modifiable risk factors included every 10 mg oral morphine equivalent consumption (1.069), every 5 postoperative hypotensive events (OR, 1.232), low hemoglobin (OR, 3.265), high glucose levels (OR, 1.887), and a high creatinine (OR, 2.874).

This study identifies potentially modifiable factors that are associated with increased LOS after THA, including postoperative opioid use and hypotensive events. Efforts to control narcotic use and initiatives aimed to reduce early postoperative hypotension could aid in reducing LOS. Furthermore, attempts should be made to correct postoperative anemia, high glucose levels, and a high creatinine level when possible.