Abstract
Introduction
CMS is now publicly reporting 30-day readmission rates following total joint replacement (TJR) by hospital and is planning the collection of patient-reported function and pain after TJR. Nationally, 5% of patients are readmitted to the hospital after TJR for both medical and orthopedic-related issues. However, the relationship between readmission and functional gain and pain relief after TJR has not been evaluated.
Methods
Clinical data on 2990 CMS patients from over 150 surgeons practicing in 22 US states who elected primary unilateral TJR in 2011–2012 were identified. Measures include pre-operative demographics, BMI, medical and musculoskeletal comorbidities, pain and function (KOOS/HOOS; SF36) and 6 month post-TJR pain and function. Data were merged with CMS claims to verify 30-day readmissions. Descriptive statistics and multivariate models adjusted for covariates and clustering within site were performed.
Results
Overall 4.7% of patients were readmitted; 2.0% due to limb related diagnoses. Readmitted patients had significantly greater number of medical comorbidities; more severe OA in non-operated knees and hips; were more likely to smoke; and have poorer pre-TJR function (all p<0.05). After TJR, a greater proportion of readmitted patients had poor global function (PCS<30= 14% vs. 8%; p<0.008) but knee/hip function was similar in both groups. Joint pain improvement did not differ by readmit status.
Conclusion
In this national representative cohort of CMS patients, patients readmitted within 30 days after TJR had poorer global function but similar joint specific function as non-readmitted patients. Readmitted patients also had significantly more medical comorbidities, more severe osteoarthritis in non-operated knees and hips; were more likely to smoke; and have poorer pre-TJR function.
The overall rate of FORCE-TJR CMS patients readmitted within 30 days (4.7%) is consistent with national CMS analyses (5%). Of interest, in our cohort, readmitted patients had poorer global function after surgery, but similar joint specific (hip/knee) function compared to patients who were not readmitted. They also had poorer pre-THR function, and more severe OA in other joints, which may contribute to their overall lower global function scores.
As CMS moves to use PROs in its bundled payment, these data support the importance of hip/knee-specific PRO measures to assess THR outcomes in quality of care programs and CMS reporting programs.
