Authors: Matthew A. Parmenter II, MS Joyce M. Harary, BA Zaid Al Nassir, MS Kevin A. Sonn, MD Leonard T. Buller, MD Evan R. Deckard, BSE R. Michael Meneghini, MD
Abstract
Background
The tenets of value based care in total hip and knee arthroplasty (THA,TKA) are to improve quality, patient’s safety, and patient care, while reducing cost by minimizing costly complications and readmissions. While readmission rates are well-studied with isolated comorbidities, data regarding the effect of cumulative “stacked” patient comorbidities are lacking. This study aimed to evaluate the effect of cumulative patient comorbidities on readmission rates within 90-days of surgery.
Methods
A retrospective review of 3,058 primary THAs and TKAs at a single institution was performed. Fifty-two possible comorbidities were manually collected from within a state-wide electronic medical record. A summation of the total number of comorbidities per patient were correlated to readmission rates within 90-days. Statistical analysis was conducted at a significance level of 0.05.
Results
Overall, the 90-day readmission rate was 4.1%. The mean number of comorbidities per patient was 1.8 (range, 0 to 9). Readmission rates increased as the number of comorbidities per patient increased (range, 2.7-25.0% per group). Patients who had 6 comorbidities demonstrated a significantly higher readmission rate within 90-days compared to those with 5 or less comorbidities (17.1 versus 3.8%, P<0.001), consistent within both THA and TKA procedures, respectively (THA 18.2% versus 4.1%, P=0.013; TKA 16.7% versus 3.5%, P<0.001). In multivariate analysis, the presence of 6 comorbidities (OR 3.4, 95% CI, 1.7-6.9, P<0.001) was the strongest predictor of readmission followed by the presence of stable coronary artery disease (OR 2.5, 95% CI, 1.5-4.2, P<0.001).
Conclusion
This data demonstrates that cumulative “stacked” comorbidities in patients who are medical optimized is a greater predictor of readmission after THA and TKA rather than one single comorbidity alone. As alternative payment and bundled care models continue to be mandated, this data is helpful for surgeons and institutions to succeed and thrive in value based care.