The Length of Stay and Readmissions of THA and TKA Patients: A Longitudinal Analysis Using a Nationwide Readmissions Data

Aim Analyze readmission trends of Total Hip Arthroplasty (THA)/Total Knee Arthroplasty (TKA) patients and examine the impact of LOS on the likelihood of hospital readmission, with an emphasis on discharge disposition and patients underlying conditions.Background Demand and cost of THA/TKA have increased over the years. However, length of stay (LOS) has decreased due to fewer after-surgery complications and advances in pain management. Overall, healthcare cost is on an upward trajectory, and the cost of unplanned readmissions constitutes a large portion of it, so it is vital to examine the relationship between LOS and unplanned readmissions.Methods and Results We use a linear probability model. LOS decreased steadily during the sampled period. Readmitted patients were more likely to be under Medicare/Medicaid and had more significant medical comorbidities. Readmission increases with LOS, but patients with fewer comorbidities are less likely to be readmitted. Patients discharged under ‘routine’ disposition were less likely to be readmitted, while those discharged against medical advice were more likely to be readmitted.Conclusion LOS impacts THA/TKA readmission rates; however, patient characteristics such as medical comorbidity and discharge disposition are essential in determining the readmission status and, therefore, necessary inputs in the decision-making processes.