What Are the Rates and Causes of Hospital Readmission After ... : Clinical Orthopaedics and Related Research® (original) (raw)
Symposium: 2013 Knee Society Proceedings
What Are the Rates and Causes of Hospital Readmission After Total Knee Arthroplasty?
Schairer, William W. BA1; Vail, Thomas P. MD1; Bozic, Kevin J. MD, MBA1, a
1 Department of Orthopaedic Surgery, University of California San Francisco, 500 Parnassus Avenue, MU 320W, 94143-0728, San Francisco, CA, USA
a e-mail; [email protected]; e-mail; [email protected]
One of the authors (TPV) certifies that he has received or may receive payments or benefits, during the study period, an amount in excess of USD 10,000 from DePuy Orthopaedics, Inc (Warsaw, IN, USA). The institution of one or more of the authors (KJB) has received, during the study period, funding from the Orthopaedic Research and Education Foundation (Rosemont, IL, USA).
All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request.
Each author certifies that institution where the work was performed approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.
Abstract
Background
Total knee arthroplasty (TKA) and related interventions such as revision TKA and the treatment of infected TKAs are commonly performed procedures. Hospital readmission rates are used to measure hospital performance, but risk factors (both medical and surgical) for readmission after TKA, revision TKA, and treatment for the infected TKA have not been well characterized.
Questions/purposes
We measured (1) the unplanned hospital readmission rate in primary TKA and revision TKA, including antibiotic-spacer staged revision TKA to treat infection. We also evaluated (2) the medical and surgical causes of readmission and (3) risk factors associated with unplanned hospital readmission.
Methods
This retrospective cohort study included a total of 1408 patients (1032 primary TKAs, 262 revision TKAs, 113 revision of infected TKAs) from one institution. All hospital readmissions within 90 days of discharge were evaluated for timing and cause. Diagnoses at readmission were categorized as surgical or medical. Readmission risk was assessed using a Cox proportional hazards model that incorporated patient demographics and medical comorbidities.
Results
The unplanned readmission rate for the entire cohort was 4% at 30 days and 8% at 90 days. At 90 days postoperatively, revision of an infected TKA had the highest readmission rate, followed by revision TKA, with primary TKA having the lowest rate. Approximately three-fourths of readmissions were the result of surgical causes, mostly infection, arthrofibrosis, and cellulitis, whereas the remainder of readmissions were the result of medical causes. Procedure type (primary TKA versus revision TKA or staged treatment for infected TKA), hospital stay more than 5 days, discharge destination, and a fluid/electrolyte abnormality were each associated with risk of unplanned readmission.
Conclusions
Patients having revision TKA, whether for infection or other causes, are more likely to have an unplanned readmission to the hospital than are patients having primary TKA. When assessing hospital performance for TKA, it is important to distinguish among these surgical procedures.
Level of Evidence
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
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