J Shoulder Elbow Surg (2014) 23, 1860-1866
www.elsevier.com/locate/ymse
Factors affecting hospital charges after total shoulder arthroplasty: an evaluation of the National Inpatient Sample database Daniel E. Davis, MDa,*, E. Scott Paxton, MDb, Mitchell Maltenfort, PhDa, Joseph Abboud, MDa a b
Department of Orthopaedic Surgery, The Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, PA, USA Department of Orthopaedic Surgery, Warren Alpert Medical School of Brown University, Providence, RI, USA Background: The number of total shoulder arthroplasties (TSA) performed in the United States increases yearly. At the same time, cost containment in health care continues to be a major concern. Therefore, it is imperative to identify specific variables that affect the cost of shoulder arthroplasty. Methods: The U.S. National Inpatient Sample database was queried (1993-2010) to evaluate total hospital charges for shoulder arthroplasty. Etiology of arthritis, multiple medical comorbidities, and patient and hospital demographics were evaluated for their effect on total inpatient hospital charges by a multivariate analysis. Results: Hospital charges for TSA increased from 1993 to 2010. Gender, race, and obesity were not associated with these differences in hospital charges. Post-traumatic and rheumatoid arthritis resulted in increased hospital charges; however, osteoarthritis resulted in decreased charges from the baseline. Multiple comorbidities (diabetes, lung disease, heart disease, and kidney disease) resulted in increased hospital charges after TSA. Regionally, the western and southern United States had the highest total charges above baseline. Larger hospitals and private urban hospitals also showed charges above baseline. Conclusions: The factors related to increased hospital charges after TSA are multifactorial and include medical comorbidities, patient demographics, and regionalization. As the future of health care continues to evolve, it is important for practitioners, legislators, insurance administrators, and hospitals to recognize factors that increase costs. Level of evidence: Level III, Cross-Sectional Design, Epidemiology Study. Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Total shoulder arthroplasty; hospital charges; medical comorbidities; regional variation; patient demographics; hospital size
Institutional Review Board approval is not applicable to this manuscript. *Reprint requests: Daniel E. Davis, MD, Department of Orthopaedic Surgery, The Rothman Institute, Thomas Jefferson University Hospital, 1025 Walnut St, 516 College Building, Philadelphia, PA 19107, USA. E-mail address: [email protected] (D.E. Davis).
Total shoulder arthroplasty (TSA) is becoming an increasingly common method of relieving the pain and disability associated with shoulder degeneration.18 This surgery has been shown to result in significant improvements in overall quality of life as well as in shoulder-specific pain
1058-2746/$ - see front matter Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2014.04.002
Hospital charges for total shoulder arthroplasty and function.6 That coupled with the increased aging of our population has led to an increased number of shoulder arthroplasties being performed in the United States each year.9 A steady increase in TSA has been shown in a populationbased study from 1976 to 2000.1 These data have been reinforced by multiple evaluations of the National Inpatient Sample (NIS) database. The NIS is a database that was created as part of the Healthcare Cost and Utilization Project.14 It is the largest all-payer inpatient database and evaluates more than 7 million hospital stays at more than 1000 hospitals, including rural and urban community and academic centers. The database approximates a 20% sample of hospitals in the United States. One evaluation of the database showed a steady rate of increase from 11 to 14 TSAs per 100,000 persons between 1990 and 2000.17 A subsequent study showed a significant increase in the number of shoulder arthroplasties performed beginning in the early 2000s,18 thought to be associated with the Food and Drug Administration approval of reverse shoulder arthroplasty in the United States. Day et al showed evidence that the rate of TSA is growing faster than the rate of total hip or total knee arthroplasties,9 which will likely lead to an increased revision burden as well as increased overall cost to the health care system. Regardless of these concerns related to revision arthroplasty, primary TSA and reverse TSA have been shown to be costeffective methods of treating glenohumeral arthritis compared with shoulder hemiarthroplasty.7,21 The purposes of this study were to use the NIS database to evaluate trends in patients undergoing TSA, to evaluate the effect that the etiology of arthritis and any associated medical comorbidities have on total hospital charges after TSA, and to analyze whether patient demographics (age, gender, and race) and hospital characteristics are factors in hospital charges after TSA. We hypothesized that significant medical comorbidities would lead to an increase in hospital cost after TSA. In addition, we hypothesized that there would be broad variability in charges based on patient demographics and hospital characteristics.
Materials and methods In the NIS database, TSA cases were flagged with the code 81.80, which has consistently been the code used to identify both anatomic and reverse TSA, in any of the procedure fields for NIS records. Diagnostic codes were used to identify the etiology of shoulder arthritis: osteoarthritis (715.91), post-traumatic arthritis (716.11), and rheumatoid arthritis (714.0). Comorbidity diagnostic codes were identified of patients with obesity (278.00), morbid obesity (278.01), diabetes (250.00), hypertension (401.0), chronic kidney disease (CKD) (585.0), chronic obstructive pulmonary disease (COPD) (496.0), congestive heart failure (CHF) (428.0), and coronary artery disease (CAD) (414.01). An additional analysis was performed holding diabetes and obesity constant to evaluate the combined effect. Finally, codes identifying complications due to surgical procedure, medical care, or not otherwise specified (996.x, 997.x, 998.x, 999.x) during the hospital stay were evaluated.
1861 Although the NIS database provides race in several categories, this variable was recorded as white and nonwhite for clearer comparisons because of a disproportionate number of white patients as discussed later. Patient age and gender were also queried from the database. Hospital size (large, medium, small) was defined by the Healthcare Cost and Utilization Project on the basis of bed number, region, and location. This value was based on the number of beds and was specific to the hospital’s region, location, and teaching status. About one third of the hospitals in a given region, location, and teaching status combination fall within each bed size category (small, medium, or large). The NIS uses different size cutoff points for rural, urban nonteaching, and urban teaching hospitals because hospitals in those categories tend to be small, medium, and large, respectively. Hospital types were defined as urban (nonrural) in a major metropolitan area (>1 million residents), small metropolitan (
www.elsevier.com/locate/ymse
Factors affecting hospital charges after total shoulder arthroplasty: an evaluation of the National Inpatient Sample database Daniel E. Davis, MDa,*, E. Scott Paxton, MDb, Mitchell Maltenfort, PhDa, Joseph Abboud, MDa a b
Department of Orthopaedic Surgery, The Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, PA, USA Department of Orthopaedic Surgery, Warren Alpert Medical School of Brown University, Providence, RI, USA Background: The number of total shoulder arthroplasties (TSA) performed in the United States increases yearly. At the same time, cost containment in health care continues to be a major concern. Therefore, it is imperative to identify specific variables that affect the cost of shoulder arthroplasty. Methods: The U.S. National Inpatient Sample database was queried (1993-2010) to evaluate total hospital charges for shoulder arthroplasty. Etiology of arthritis, multiple medical comorbidities, and patient and hospital demographics were evaluated for their effect on total inpatient hospital charges by a multivariate analysis. Results: Hospital charges for TSA increased from 1993 to 2010. Gender, race, and obesity were not associated with these differences in hospital charges. Post-traumatic and rheumatoid arthritis resulted in increased hospital charges; however, osteoarthritis resulted in decreased charges from the baseline. Multiple comorbidities (diabetes, lung disease, heart disease, and kidney disease) resulted in increased hospital charges after TSA. Regionally, the western and southern United States had the highest total charges above baseline. Larger hospitals and private urban hospitals also showed charges above baseline. Conclusions: The factors related to increased hospital charges after TSA are multifactorial and include medical comorbidities, patient demographics, and regionalization. As the future of health care continues to evolve, it is important for practitioners, legislators, insurance administrators, and hospitals to recognize factors that increase costs. Level of evidence: Level III, Cross-Sectional Design, Epidemiology Study. Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Total shoulder arthroplasty; hospital charges; medical comorbidities; regional variation; patient demographics; hospital size
Institutional Review Board approval is not applicable to this manuscript. *Reprint requests: Daniel E. Davis, MD, Department of Orthopaedic Surgery, The Rothman Institute, Thomas Jefferson University Hospital, 1025 Walnut St, 516 College Building, Philadelphia, PA 19107, USA. E-mail address: [email protected] (D.E. Davis).
Total shoulder arthroplasty (TSA) is becoming an increasingly common method of relieving the pain and disability associated with shoulder degeneration.18 This surgery has been shown to result in significant improvements in overall quality of life as well as in shoulder-specific pain
1058-2746/$ - see front matter Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2014.04.002
Hospital charges for total shoulder arthroplasty and function.6 That coupled with the increased aging of our population has led to an increased number of shoulder arthroplasties being performed in the United States each year.9 A steady increase in TSA has been shown in a populationbased study from 1976 to 2000.1 These data have been reinforced by multiple evaluations of the National Inpatient Sample (NIS) database. The NIS is a database that was created as part of the Healthcare Cost and Utilization Project.14 It is the largest all-payer inpatient database and evaluates more than 7 million hospital stays at more than 1000 hospitals, including rural and urban community and academic centers. The database approximates a 20% sample of hospitals in the United States. One evaluation of the database showed a steady rate of increase from 11 to 14 TSAs per 100,000 persons between 1990 and 2000.17 A subsequent study showed a significant increase in the number of shoulder arthroplasties performed beginning in the early 2000s,18 thought to be associated with the Food and Drug Administration approval of reverse shoulder arthroplasty in the United States. Day et al showed evidence that the rate of TSA is growing faster than the rate of total hip or total knee arthroplasties,9 which will likely lead to an increased revision burden as well as increased overall cost to the health care system. Regardless of these concerns related to revision arthroplasty, primary TSA and reverse TSA have been shown to be costeffective methods of treating glenohumeral arthritis compared with shoulder hemiarthroplasty.7,21 The purposes of this study were to use the NIS database to evaluate trends in patients undergoing TSA, to evaluate the effect that the etiology of arthritis and any associated medical comorbidities have on total hospital charges after TSA, and to analyze whether patient demographics (age, gender, and race) and hospital characteristics are factors in hospital charges after TSA. We hypothesized that significant medical comorbidities would lead to an increase in hospital cost after TSA. In addition, we hypothesized that there would be broad variability in charges based on patient demographics and hospital characteristics.
Materials and methods In the NIS database, TSA cases were flagged with the code 81.80, which has consistently been the code used to identify both anatomic and reverse TSA, in any of the procedure fields for NIS records. Diagnostic codes were used to identify the etiology of shoulder arthritis: osteoarthritis (715.91), post-traumatic arthritis (716.11), and rheumatoid arthritis (714.0). Comorbidity diagnostic codes were identified of patients with obesity (278.00), morbid obesity (278.01), diabetes (250.00), hypertension (401.0), chronic kidney disease (CKD) (585.0), chronic obstructive pulmonary disease (COPD) (496.0), congestive heart failure (CHF) (428.0), and coronary artery disease (CAD) (414.01). An additional analysis was performed holding diabetes and obesity constant to evaluate the combined effect. Finally, codes identifying complications due to surgical procedure, medical care, or not otherwise specified (996.x, 997.x, 998.x, 999.x) during the hospital stay were evaluated.
1861 Although the NIS database provides race in several categories, this variable was recorded as white and nonwhite for clearer comparisons because of a disproportionate number of white patients as discussed later. Patient age and gender were also queried from the database. Hospital size (large, medium, small) was defined by the Healthcare Cost and Utilization Project on the basis of bed number, region, and location. This value was based on the number of beds and was specific to the hospital’s region, location, and teaching status. About one third of the hospitals in a given region, location, and teaching status combination fall within each bed size category (small, medium, or large). The NIS uses different size cutoff points for rural, urban nonteaching, and urban teaching hospitals because hospitals in those categories tend to be small, medium, and large, respectively. Hospital types were defined as urban (nonrural) in a major metropolitan area (>1 million residents), small metropolitan (
