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Risk Factors for Increased Hospital Cost for Primary Total Knee Arthroplasty
Matthew Goldner1, Hemant P Reddy1, Michael Biskup1
1Montefiore Medical Center/Albert Einstein College of Medicine, Department of Orthopedic Surgery, Bronx, New York.
Insights
Higher medical comorbidity scores, including obesity (body mass index ≥ 35), diabetes, and heart failure, significantly increase the cost of primary total knee arthroplasty (TKA). Understanding these factors is crucial for managing TKA expenses.
Area of Science:
- Orthopedic Surgery
- Health Economics
- Medical Comorbidity Research
Background:
- Patients with complex medical comorbidities incur higher costs for primary total knee arthroplasty (TKA).
- Quantifying the impact of these comorbidities on TKA expenses is essential for cost management.
Purpose of the Study:
- To evaluate and quantify the influence of medical comorbidities on the overall cost of primary TKA.
- Identify specific patient factors that independently increase TKA hospitalization expenses.
Main Methods:
- Retrospective review of 3,077 primary TKA patient billing records (CPT code 27447) from January 2017 to March 2020.
- Analysis of cost data including anesthesia, operating room, surgeon fees, recovery, room and board, physical therapy, and medical supplies.
- Gamma regression analyses to identify associations between patient demographics, comorbidities (e.g., BMI, ASA score, CCI), and increased TKA costs.
Main Results:
- Median TKA cost was $32,129, with medical supplies ($14,966) and room/board ($4,976) as major cost drivers.
- Independent risk factors for increased cost included BMI ≥ 35, American Society of Anesthesiologists (ASA) scores of 3-4, diabetes, congestive heart failure (CHF), and mild liver disease.
- Higher Charlson Comorbidity Index (CCI) scores correlated with increased total costs, with median costs rising from $31,545 (CCI 0-5) to $35,099 (CCI ≥ 5).
Conclusions:
- Elevated BMI (≥ 35), ASA scores (3-4), diabetes, CHF, and mild liver disease are significant independent risk factors for higher costs in primary TKA.
- The overall cost of primary TKA escalates with increasing patient comorbidity burden, as indicated by CCI scores.
Background:
Patients who have more complex medical comorbidities increase the cost of primary total knee arthroplasty (TKA). The goal of this study was to evaluate and quantify the impact of medical comorbidities on the cost of primary TKA.
Methods:
Hospital billing data for 3,077 primary TKA patients (Current Procedural Terminology code 27447) from January 2017 to March 2020 at a high-volume academic medical center were retrospectively reviewed. Cost data included expenses associated with the index procedure: anesthesia, operating room costs, the orthopaedic surgeon, the recovery room, hospital room and board, physical therapy, and medical supplies. Patient demographics, comorbidities, and admission data were collected. Univariate and multivariate gamma regression analyses were performed to identify associations with increased cost during primary TKA admissions.
Results:
The median cost of TKA was $32,129. The highest proportion of cost was attributed to medical supplies, which accounted for $14,966 (46%), followed by room and board at $4,976 (15%) and the operating room at $4,267 ($13%). Body mass index ≥ 35, American Society of Anesthesiologists score of 3 to 4, diabetes, congestive heart failure, and mild liver disease were found to be independent risk factors for increased cost. Total cost increased with increasing Charlson Comorbidity Index (CCI) scores, with a median total cost of $31,545 for CCI scores of 0 to 5 and a median total cost of $35,099 for CCI scores of 5 or more.
Conclusion:
Body mass index ≥ 35, American Society of Anesthesiologists 3 to 4, diabetes, congestive heart failure, and mild liver disease were independent risk factors for increased cost during the index hospitalization for a primary TKA. The cost of primary TKA increased as CCI increased.
