A study published online in the journal Arthritis Care & Research suggests that various comorbidity indices offer weak discrimination for the prediction of post-acute discharge settings and hospital readmission for patients following joint arthroplasty. The authors retrospectively reviewed data on 607,349 Medicare beneficiaries who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA). 

They found that 30-, 60-, and 90-day unplanned hospital readmission rates were 5.3 percent, 7.2 percent, and 8.5 percent respectively. The authors note that the C-statistic for the base model in predicting post-acute discharge setting and 30-, 60-, and 90-day readmission in TKA and THA were between 0.63 and 0.67. "Adding Charlson, Elixhauser, or the U.S. Centers for Medicare & Medicaid Services (CMS) risk adjustment model Hierarchical Condition Category increased the C-statistic minimally from the base model for predicting both discharge settings and hospital readmission," they write. Conditions most frequently associated with hospital readmission were diabetes, pulmonary disease, arrhythmias, and heart disease. Learn more...