Preoperative predictors of unplanned emergency department visits following total hip arthroplasty

Unplanned emergency department (ED) visits following total hip arthroplasty (THA) can be a substantial cost burden for the patient and may adversely affect reimbursements in bundled payment models. Identifying preoperative risk factors that predispose patients to visit the ED could influence patient optimization. Adult patients who underwent THA between 2018-2024 were included in this retrospective cohort study. ED utilization within 90 days of surgery was quantified and their underlying reasons were categorized. Patient demographics, hospital-related outcomes, and patient-reported outcome measures (PROMs) were compared. Backward logistic regression was performed to identify preoperative parameters that were predictive of ED visits. Among 1,688 included patients, the mean age was 67.9 years, 53.4% were female, and mean BMI was 30.0kg/m2. In total, 170 (10.1%) patients visited the ED within 90 days of their THA, commonly due to musculoskeletal pain/swelling (24.8%), cardiovascular/respiratory concerns (18.4%), or infections (16.8%). Preoperatively, ED users had higher mean BMI, comorbidities, Medicare insurance utilization, preoperative narcotics use history, and preoperative assistive device use and fall history; they also had lower employment rates and often lacked care partners (p<0.05). ED users were comparable with regards to length of stay, rehab discharge, outpatient services utilization, and time off work (p>0.05). ED users also had worse PROMs, including VAS pain, PROMIS Overall, Physical, and Mental, and HOOS Jr, both preoperatively and 1-year postoperatively (p<0.05). Regression analysis identified unemployment (OR=1.5, 95%CI=1.0-2.2), heart disease (OR=1.8, 95%CI=1.0-3.0), depression (OR=1.6, 95%CI=1.0-2.6), and low PROMIS mental scores (OR=1.1, 95%CI=0.9-1.0) as independent predictors of ED utilization (p<0.05). One in ten patients require ED services following THA, commonly due to joint pain/swelling, cardiovascular/respiratory concerns, or infections. Unemployment, history of heart disease or depression, and worse preoperative PROMIS Mental scores predicted ED utilization. Careful identification and optimization of these patients prior to THA may reduce healthcare utilization.