ORIGINAL ARTICLE
Health Care Burden of Anterior Cervical Spine Surgery National Trends in Hospital Charges and Length of Stay, 2000–2009 Hassan Alosh, MD, David Li, BS, Lee H. Riley, III, MD, and Richard L. Skolasky, ScD
Study Design: A retrospective review. Objective: Our goals were: (1) to document national trends in total hospital charges and length of stay (LOS) associated with anterior cervical spine procedures from 2000 through 2009 and (2) to evaluate how those trends relate to demographic factors. Summary of Background Data: Since 2000, the number of anterior cervical spine procedures has increased dramatically in the United States. Materials and Methods: We reviewed 86,622,872 hospital discharge records (2000–2009) from the Nationwide Inpatient Sample and used ICD-9-CM codes to identify anterior cervical spine procedures (927,103). We assessed those records for outcomes (total hospital charges, LOS) and covariates (age, sex, race/ethnicity, insurance status, geographic location, comorbidities, presence of traumatic cervical spine injury on admission) of interest and determined (with multivariable linear regression models) the independent effects of covariates on outcomes (significance, P < 0.05). Results: From 2000 through 2009, yearly charges significantly increased ($1.62 billion to $5.63 billion, respectively) and LOS significantly decreased (2.23 ± 0.043 d to 2.20 ± 0.045 d, respectively). The average hospital charges increased yearly after adjustment for covariates. All covariates but age were significant, independent predictors of hospital charges and LOS. Conclusions: To our knowledge, this investigation is the first to identify the significant demographic predictors of hospital charges and LOS associated with anterior cervical spine surgery. Key Words: anterior cervical spine surgery, length of stay, hospital charges, disparity (J Spinal Disord Tech 2015;28:5–11)
T
he United States spends more on health care than any other Western nation.1 Rising health care charges
Received for publication March 28, 2013; accepted August 27, 2013. From the Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD. The authors declare no conflict of interest. Reprints: Richard L. Skolasky, ScD, c/o Elaine P. Henze, BJ, ELS, Medical Editor and Director, Editorial Services, Department of Orthopaedic Surgery, The Johns Hopkins University/Johns Hopkins Bayview Medical Center, 4940 Eastern Ave., #A665, Baltimore, MD 21224-2780 (e-mail: [email protected]). Copyright r 2013 Wolters Kluwer Health, Inc. All rights reserved.
J Spinal Disord Tech
Volume 28, Number 1, February 2015
have recently garnered national attention, prompting physician and public debate over how to manage more judiciously the expenditures associated with certain specialties, such as spine care.2,3 Anterior cervical spine surgery is the preferred treatment for degenerative spine disease in the United States,4,5 and the rising number of these procedures has been accompanied by increases in patient diversity, age, and number of comorbidities.6 Disparities in hip and knee arthroplasty [eg, hospital charges and length of stay (LOS)] along such demographic factors have been documented.7–11 In addition, disparities in access to treatment and in outcomes have been shown among patients with idiopathic scoliosis.12 However, to our knowledge, no study has investigated how such factors relate to associated charges and LOS of anterior cervical spine surgery. Our goals were: (1) to document national trends in total hospital charges and LOS associated with anterior cervical spine procedures from 2000 through 2009 and (2) to evaluate how those trends relate to the demographic factors of age, sex, race/ethnicity, insurance status, geographic location, comorbidities, and the presence of traumatic cervical spine injury on hospital admission.
MATERIALS AND METHODS Data Source We analyzed all 86,622,872 hospital discharge records from 2000 through 2009 from the Nationwide Inpatient Sample (NIS) for discharge data. NIS is the largest all-payer inpatient database in the United States and approximates a 20% sample of all United States community hospitals, stratified by geographic region, ownership, metropolitan location, teaching status, and size to ensure broad representation. Every entry in the database represents a single hospitalization record.
Data Selection We used criteria based on the ICD-9-CM International Classification of Diseases, Ninth Revision, Clinical Modification13 (Appendix) to select the NIS for hospital discharge records of patients 18 years or older that contained a primary diagnosis code of cervical spine disk disease and an ICD-9-CM procedure code for anterior cervical spine procedure (N = 927,103).6,14 www.jspinaldisorders.com |
5
Alosh et al
J Spinal Disord Tech
Outcomes of Interest
Patient Demographic Data
The outcomes of interest were total hospital charges for an anterior cervical spine procedure, which were adjusted for inflation using the Bureau of Labor Statistics’ Consumer Price Index for Medical Care, and LOS per admission for that procedure (Fig. 1). Hospital charges include inpatient charges, surgical charges, instrumentation charges, and charges for supplementation. All references to total hospital charges reflect the value of total hospital charges in United States dollars for the year 2009.15
The mean age and CCI score of patients undergoing anterior cervical spine surgery increased during the period of observation, as did the proportion of women and nonwhite patients. Patients with primary insurance coverage by private insurance comprised most of the patient population, and most procedures were performed in the South, followed by the West, the Northeast, and the Midwest (Table 1).
Secondary Outcomes Covariates of interest were age, sex, race/ethnicity, insurance status, geographic location, comorbidities, and the presence of traumatic cervical spine injury on hospital admission. Race/ethnicity was classified into 3 categories based on United States Census definitions: white (nonHispanic), black (non-Hispanic), and Hispanic. Other racial categories were not considered in this analysis because of concern for bias from underrepresentation of these groups in the NIS data. Insurance status was categorized as Medicare, Medicaid, or private. The NIS classifies additional insurance status to include self-pay, no charge, other, and missing. “Other” refers to worker’s compensation, CHAMPUS, CHAMPVA, Title V, and other government programs.16 For the sake of clarity, we did not include these additional insurance status classifications. Geographic location was defined per the United States Census criteria into Northeast, Midwest, South, and West. We determined comorbidity status using a modified Charlson Comorbidity Index (CCI)17,18 score and examined for the presence of traumatic cervical spine injury on hospital admission using the ICD-9-CM selection criteria.
Volume 28, Number 1, February 2015
Statistical Analysis We performed all data analysis with a standard statistical software package (Stata 10SE, StataCorp LP, College Station, TX). Statistical significance was set at a P-value
Health Care Burden of Anterior Cervical Spine Surgery National Trends in Hospital Charges and Length of Stay, 2000–2009 Hassan Alosh, MD, David Li, BS, Lee H. Riley, III, MD, and Richard L. Skolasky, ScD
Study Design: A retrospective review. Objective: Our goals were: (1) to document national trends in total hospital charges and length of stay (LOS) associated with anterior cervical spine procedures from 2000 through 2009 and (2) to evaluate how those trends relate to demographic factors. Summary of Background Data: Since 2000, the number of anterior cervical spine procedures has increased dramatically in the United States. Materials and Methods: We reviewed 86,622,872 hospital discharge records (2000–2009) from the Nationwide Inpatient Sample and used ICD-9-CM codes to identify anterior cervical spine procedures (927,103). We assessed those records for outcomes (total hospital charges, LOS) and covariates (age, sex, race/ethnicity, insurance status, geographic location, comorbidities, presence of traumatic cervical spine injury on admission) of interest and determined (with multivariable linear regression models) the independent effects of covariates on outcomes (significance, P < 0.05). Results: From 2000 through 2009, yearly charges significantly increased ($1.62 billion to $5.63 billion, respectively) and LOS significantly decreased (2.23 ± 0.043 d to 2.20 ± 0.045 d, respectively). The average hospital charges increased yearly after adjustment for covariates. All covariates but age were significant, independent predictors of hospital charges and LOS. Conclusions: To our knowledge, this investigation is the first to identify the significant demographic predictors of hospital charges and LOS associated with anterior cervical spine surgery. Key Words: anterior cervical spine surgery, length of stay, hospital charges, disparity (J Spinal Disord Tech 2015;28:5–11)
T
he United States spends more on health care than any other Western nation.1 Rising health care charges
Received for publication March 28, 2013; accepted August 27, 2013. From the Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD. The authors declare no conflict of interest. Reprints: Richard L. Skolasky, ScD, c/o Elaine P. Henze, BJ, ELS, Medical Editor and Director, Editorial Services, Department of Orthopaedic Surgery, The Johns Hopkins University/Johns Hopkins Bayview Medical Center, 4940 Eastern Ave., #A665, Baltimore, MD 21224-2780 (e-mail: [email protected]). Copyright r 2013 Wolters Kluwer Health, Inc. All rights reserved.
J Spinal Disord Tech
Volume 28, Number 1, February 2015
have recently garnered national attention, prompting physician and public debate over how to manage more judiciously the expenditures associated with certain specialties, such as spine care.2,3 Anterior cervical spine surgery is the preferred treatment for degenerative spine disease in the United States,4,5 and the rising number of these procedures has been accompanied by increases in patient diversity, age, and number of comorbidities.6 Disparities in hip and knee arthroplasty [eg, hospital charges and length of stay (LOS)] along such demographic factors have been documented.7–11 In addition, disparities in access to treatment and in outcomes have been shown among patients with idiopathic scoliosis.12 However, to our knowledge, no study has investigated how such factors relate to associated charges and LOS of anterior cervical spine surgery. Our goals were: (1) to document national trends in total hospital charges and LOS associated with anterior cervical spine procedures from 2000 through 2009 and (2) to evaluate how those trends relate to the demographic factors of age, sex, race/ethnicity, insurance status, geographic location, comorbidities, and the presence of traumatic cervical spine injury on hospital admission.
MATERIALS AND METHODS Data Source We analyzed all 86,622,872 hospital discharge records from 2000 through 2009 from the Nationwide Inpatient Sample (NIS) for discharge data. NIS is the largest all-payer inpatient database in the United States and approximates a 20% sample of all United States community hospitals, stratified by geographic region, ownership, metropolitan location, teaching status, and size to ensure broad representation. Every entry in the database represents a single hospitalization record.
Data Selection We used criteria based on the ICD-9-CM International Classification of Diseases, Ninth Revision, Clinical Modification13 (Appendix) to select the NIS for hospital discharge records of patients 18 years or older that contained a primary diagnosis code of cervical spine disk disease and an ICD-9-CM procedure code for anterior cervical spine procedure (N = 927,103).6,14 www.jspinaldisorders.com |
5
Alosh et al
J Spinal Disord Tech
Outcomes of Interest
Patient Demographic Data
The outcomes of interest were total hospital charges for an anterior cervical spine procedure, which were adjusted for inflation using the Bureau of Labor Statistics’ Consumer Price Index for Medical Care, and LOS per admission for that procedure (Fig. 1). Hospital charges include inpatient charges, surgical charges, instrumentation charges, and charges for supplementation. All references to total hospital charges reflect the value of total hospital charges in United States dollars for the year 2009.15
The mean age and CCI score of patients undergoing anterior cervical spine surgery increased during the period of observation, as did the proportion of women and nonwhite patients. Patients with primary insurance coverage by private insurance comprised most of the patient population, and most procedures were performed in the South, followed by the West, the Northeast, and the Midwest (Table 1).
Secondary Outcomes Covariates of interest were age, sex, race/ethnicity, insurance status, geographic location, comorbidities, and the presence of traumatic cervical spine injury on hospital admission. Race/ethnicity was classified into 3 categories based on United States Census definitions: white (nonHispanic), black (non-Hispanic), and Hispanic. Other racial categories were not considered in this analysis because of concern for bias from underrepresentation of these groups in the NIS data. Insurance status was categorized as Medicare, Medicaid, or private. The NIS classifies additional insurance status to include self-pay, no charge, other, and missing. “Other” refers to worker’s compensation, CHAMPUS, CHAMPVA, Title V, and other government programs.16 For the sake of clarity, we did not include these additional insurance status classifications. Geographic location was defined per the United States Census criteria into Northeast, Midwest, South, and West. We determined comorbidity status using a modified Charlson Comorbidity Index (CCI)17,18 score and examined for the presence of traumatic cervical spine injury on hospital admission using the ICD-9-CM selection criteria.
Volume 28, Number 1, February 2015
Statistical Analysis We performed all data analysis with a standard statistical software package (Stata 10SE, StataCorp LP, College Station, TX). Statistical significance was set at a P-value
