Abstract
Introduction
Readmission after Total Hip Arthroplasty (THA) or Total Knee Arthroplasty (TKA) places a great burden on the health care system. As reimbursement systems place increased emphasis on quality measures such as readmission rates, identifying and understanding the most common drivers for readmission becomes increasingly important.
Methods
We queried an electronic database for all patients who underwent THA or TKA at our institution from 2006 through 2010. We identified those who were readmitted within 90 days of discharge from the initial admission and set this as our outcome variable. We then reviewed demographic and clinical data such as age, index procedure, length of stay (LOS), readmission diagnosis, co-morbidities and payer group and set these as our variables of interest. We used chi-square tests to characterize and summarize the patient data and logistic regression analyses to predict the relative likelihood of patient readmission based on our control variables. Statistical significance was defined as p <0.05.
Results
6436 patients underwent THA or TKA during the study period. Patients who were readmitted had a significantly higher mean LOS (4.7 days vs. 3.4 days, p <0.0001). Patients with any co-morbid conditions (e.g., CHF, COPD, diabetes, PE, CAD) had higher readmission rates than those with none (18.7% vs. 7.8%, p =0.0002). Adjusting for patient age, sex, race, payer type, and LOS, those with CHF or CAD were more likely to be readmitted compared to those without CHF or CAD (CHF: odds ratio [OR] =1.71, 95% confidence interval [CI]=1.03–2.84; CAD: [OR] =1.93, 95% CI=1.48–2.53).
Conclusions
In our analysis of patients undergoing THA and TKA between 2006 and 2010, we found significant associations between readmission and higher LOS during initial admission and the presence of co-morbidities. Longer than average LOS and the presence of co-morbidities may be early predictors of readmission and warrant further study.
