Patient Factors and Cost Associated with 90-Day Readmission Following Total Hip Arthroplasty.

This study sought to identify specific costs for 90-day readmissions following total hip arthroplasty in a bundled payment system. Hospital billing records revealed 139 readmissions (8.93%) in 1781 patients. Mean costs for surgical readmissions were greater (P=0.002) compared with medical reasons, but similar for Medicare/Medicaid and private payers (P=0.975). Costs for imaging, laboratory workup, medication and transfusions, and hospital cost correlated with increasing SOI (P<0.05). Patients transferred from outside hospitals or rehabilitation had higher hospital (P=0.006) and operating room costs (P=0.001) compared to patients admitted from ED or clinic. Hospitals that care for complex patients with Medicare/Medicaid may experience increased costs for unplanned 90-day readmissions highlighting considerations for payer mix.