Acute Care Surgery: Defining Mortality in Emergency General Surgery in the State of Maryland Mayur Narayan, MD, MPH, MBA, FACS, Ronald Tesoriero, MD, FACS, Brandon R Bruns, Elena N Klyushnenkova, PhD, Hegang Chen, PhD, Jose J Diaz, MD, CNS, FACS
MD, FACS,
Emergency general surgery (EGS) is a major component of acute care surgery, however, limited data exist on mortality with respect to trauma center (TC) designation. We hypothesized that mortality would be lower for EGS patients treated at a TC vs non-TC (NTC). STUDY DESIGN: A retrospective review of the Maryland Health Services Cost Review Commission database from 2009 to 2013 was performed. The American Association for the Surgery of Trauma EGS ICD-9 codes were used to identify EGS patients. Data collected included demographics, TC designation, emergency department admissions, and All Patients Refined Severity of Illness (APR_SOI). Trauma center designation was used as a marker of a formal acute care surgery program. Primary outcomes included in-hospital mortality. Multivariable logistic regression analysis was performed controlling for age. RESULTS: There were 817,942 EGS encounters. Mean SD age of patients was 60.1 18.7 years, 46.5% were males; 71.1% of encounters were at NTCs; and 75.8% were emergency department admissions. Overall mortality was 4.05%. Mortality was calculated based on TC designation controlling for age across APR_SOI strata. Multivariable logistic regression analysis did not show statistically significant differences in mortality between hospital levels for minor APR_SOI. For moderate APR_SOI, mortality was significantly lower for TCs compared with NTCs (p < 0.001). Among TCs, the effect was strongest for Level I TC (odds ratio ¼ 0.34). For extreme APR_SOI, mortality was higher at TCs vs NTCs (p < 0.001). CONCLUSIONS: Emergency general surgery patients treated at TCs had lower mortality for moderate APR_SOI, but increased mortality for extreme APR_SOI when compared with NTCs. Additional investigation is required to better evaluate this unexpected finding. (J Am Coll Surg 2015;220:762e770. 2015 by the American College of Surgeons)
BACKGROUND:
The evolution of trauma care in the United States has had a significant impact on trauma mortality. Multiple studies have shown that risk of death is considerably lower when care is provided at a trauma center (TC) than a none trauma center (NTC).1 It has also been reported that higher TC patient volume is associated with improvements in mortality and length of stay (LOS).2 These
improvements in outcomes led to the push for regionalized care and the development of well-coordinated trauma systems. MacKenzie and colleagues3 were able to show that regionalization of trauma care not only reduced mortality but was also cost effective. The American College of Surgeons verifies the presence of resources based on TC designation as listed in Resources for Optimal Care of the Injured Patients.4 Level I TCs, maintaining a constant availability of comprehensive surgical services, have become the natural choice for transfer of injured patients from community hospitals that lack such structure and support. Additionally, higher TC designation based on level of care has also been shown to have better survival rates and outcomes than lower-level TCs or NTCs.5 In addition to trauma and surgical critical care, emergency general surgery (EGS) is a major component of the acute care surgery model. Implementation of an acute
Disclosure Information: Nothing to disclose. Presented at the Southern Surgical Association 126th Annual Meeting, Palm Beach, FL, November 30eDecember 3, 2014. Received December 17, 2014; Revised December 17, 2014; Accepted December 17, 2014. From the Division of Acute Care Surgery, Program in Trauma, R Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, MD. Correspondence address: Mayur Narayan, MD, MPH, MBA, FACS, Division of Acute Care Surgery, Program in Trauma, R Adams Cowley Shock Trauma Center, University of Maryland, 22 South Greene St, Office T1R40, Baltimore, MD 21201. email: [email protected]
ª 2015 by the American College of Surgeons Published by Elsevier Inc.
762
http://dx.doi.org/10.1016/j.jamcollsurg.2014.12.051 ISSN 1072-7515/15
Vol. 220, No. 4, April 2015
Narayan et al
Abbreviations and Acronyms
APR_SOI DRG ED EGS HSCRC LOS NTC OR TC
¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼
All Patients Refined Severity of Illness diagnosis related group emergency department emergency general surgery Health Services Cost Review Commission length of stay nonetrauma center odds ratio trauma center
care surgery service is highly resource intensive and requires dedicated support staffing, intensive care, operating room availability, and a skilled surgical workforce.6 Hospitals with dedicated acute care surgery services have reported a shorter LOS and decreased time to operation, along with decreased morbidity for common emergency surgical procedures.7-12 As a result of the improved efficiency and quality of care, some have hypothesized that progression to EGS regionalization seems the logical next step.13,14 Currently, limited data exist defining the overall mortality of the EGS patient population. It is also unclear whether the existence of a designated TC has an impact on EGS outcomes. Given the considerable resources that inherently exist at designated TCs, we hypothesized that mortality would be lower for EGS patients treated at a TC vs NTC.
METHODS A retrospective review of the Maryland Health Services Cost Review Commission (HSCRC) database from 2009 to 2013 was performed. The Maryland HSCRC was created in the 1970s as a result of a waiver by the federal government exempting the state from national Medicare and Medicaid reimbursement principles.15 The HSCRC was mandated to review and approve reasonable hospital rates and publicly disclose information on the costs and financial performance of Maryland hospitals. Since its inception, all payers pay Maryland hospitals on the basis of the rates established by the HSCRC.16 The HSCRC Inpatient Data Set contains discharge medical record abstract and billing data on each of the state’s approximately 800,000 inpatient admissions annually. Hospitals submit data to the HSCRC on a quarterly basis. The HSCRC Research Data File was generated after approval by the HSCRC Review Board and confirmation of the Research Data Use Agreement. Analysis was performed using hospital discharge data from the HSCRC database, which provides information about the index hospital admission and is limited to 30 days
Mortality in Emergency General Surgery
763
of follow-up. The University of Maryland, Baltimore Internal Review Board approved the study. In 2013, the American Association for the Surgery of Trauma published its defined collection of EGS ICD-9 codes.17 From the HSCRC database, a patient was classified as an EGS patient if at least 1 of the 15 ICD-9 diagnosis codes recorded matched an American Association for the Surgery of Trauma EGS ICD-9 code. All adult patients aged 18 years or older were included in the analysis. Other variables collected included age, sex, race, hospital LOS, ICU LOS, emergency department (ED) admission, and All Patients Refined Severity of Illness (APR_SOI). Diagnosis related groups (DRGs), developed at Yale University in the 1960s, are a patient-classification method that provide a means of relating the type of patients a hospital treats (case mix) to costs incurred by that hospital. Three major versions of the DRG are currently in use: Basic DRGs, All Patient DRGs, and All Patient Refined DRGs. The Basic DRGs are used by the Centers for Medicare and Medicaid Services for hospital payment for Medicare beneficiaries. The All Patient DRGs expand on the Basic DRGs and are more representative of non-Medicare populations. The original objective of DRGs was to develop a patient classification system that related the types of patients treated to the resources they consumed. The DRGs focused exclusively on resource intensity. A new classification incorporating patient severity of illness and risk of mortality, in addition to resource use, was developed to enable comparison of hospitals across a wide range of resource and outcome measures. The All Patient Refined DRG incorporates severity of illness subclasses. The APR_SOI is defined by the extent of physiologic decompensation or organ system loss of function. The HSCRC database uses this definition to stratify patients into 4 levels based on severity of illness: minor, moderate, major, and extreme.15-18 Additional data collected included the nature of admission (emergent/urgent, or other). Hospitals were divided into TC vs NTC. The TC designation (Level I, II, or III) was obtained from the Maryland Institute for Emergency Medical Services Systems. Level I TCs are tertiary care facilities that are capable of providing comprehensive care of the trauma patient. These centers also provide prevention and rehabilitation resources. Staffing includes 24-hour in-house coverage by general surgeons and prompt availability of care in specialties such as orthopaedic surgery, neurosurgery, anesthesiology, emergency medicine, radiology, internal medicine, plastic surgery, oral and maxillofacial, pediatric, and critical care. Level II TCs are able to initiate definitive care for all injured patients. Staffing in this model includes 24-hour immediate coverage by general surgeons, as well as coverage by
764
Table 1.
Narayan et al
J Am Coll Surg
Mortality in Emergency General Surgery
Demographics of HCSCRC Database from 2009 to 2013
Variable
Population, n (%) Age, y, mean SD Sex, n (%) Male Female Unknown Race, n (%) White Black Other Hospital LOS, d, median (IQR) Hospital LOS, n (%) 0d 1e4 d >4 d LOS ICU, n (%) 0d 1 d ICU 1, d, median (IQR) ED admissions, n (%) Yes No APR_SOI, n (%) Minor Moderate Major Extreme Trauma level, n (%) None III II I
Total
Alive
Expired
p Value*
817,942 60.1 18.7
784,778 (95.95) 59.7 18.7
33,164 (4.05) 71.0 15.3
MD, FACS,
Emergency general surgery (EGS) is a major component of acute care surgery, however, limited data exist on mortality with respect to trauma center (TC) designation. We hypothesized that mortality would be lower for EGS patients treated at a TC vs non-TC (NTC). STUDY DESIGN: A retrospective review of the Maryland Health Services Cost Review Commission database from 2009 to 2013 was performed. The American Association for the Surgery of Trauma EGS ICD-9 codes were used to identify EGS patients. Data collected included demographics, TC designation, emergency department admissions, and All Patients Refined Severity of Illness (APR_SOI). Trauma center designation was used as a marker of a formal acute care surgery program. Primary outcomes included in-hospital mortality. Multivariable logistic regression analysis was performed controlling for age. RESULTS: There were 817,942 EGS encounters. Mean SD age of patients was 60.1 18.7 years, 46.5% were males; 71.1% of encounters were at NTCs; and 75.8% were emergency department admissions. Overall mortality was 4.05%. Mortality was calculated based on TC designation controlling for age across APR_SOI strata. Multivariable logistic regression analysis did not show statistically significant differences in mortality between hospital levels for minor APR_SOI. For moderate APR_SOI, mortality was significantly lower for TCs compared with NTCs (p < 0.001). Among TCs, the effect was strongest for Level I TC (odds ratio ¼ 0.34). For extreme APR_SOI, mortality was higher at TCs vs NTCs (p < 0.001). CONCLUSIONS: Emergency general surgery patients treated at TCs had lower mortality for moderate APR_SOI, but increased mortality for extreme APR_SOI when compared with NTCs. Additional investigation is required to better evaluate this unexpected finding. (J Am Coll Surg 2015;220:762e770. 2015 by the American College of Surgeons)
BACKGROUND:
The evolution of trauma care in the United States has had a significant impact on trauma mortality. Multiple studies have shown that risk of death is considerably lower when care is provided at a trauma center (TC) than a none trauma center (NTC).1 It has also been reported that higher TC patient volume is associated with improvements in mortality and length of stay (LOS).2 These
improvements in outcomes led to the push for regionalized care and the development of well-coordinated trauma systems. MacKenzie and colleagues3 were able to show that regionalization of trauma care not only reduced mortality but was also cost effective. The American College of Surgeons verifies the presence of resources based on TC designation as listed in Resources for Optimal Care of the Injured Patients.4 Level I TCs, maintaining a constant availability of comprehensive surgical services, have become the natural choice for transfer of injured patients from community hospitals that lack such structure and support. Additionally, higher TC designation based on level of care has also been shown to have better survival rates and outcomes than lower-level TCs or NTCs.5 In addition to trauma and surgical critical care, emergency general surgery (EGS) is a major component of the acute care surgery model. Implementation of an acute
Disclosure Information: Nothing to disclose. Presented at the Southern Surgical Association 126th Annual Meeting, Palm Beach, FL, November 30eDecember 3, 2014. Received December 17, 2014; Revised December 17, 2014; Accepted December 17, 2014. From the Division of Acute Care Surgery, Program in Trauma, R Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, MD. Correspondence address: Mayur Narayan, MD, MPH, MBA, FACS, Division of Acute Care Surgery, Program in Trauma, R Adams Cowley Shock Trauma Center, University of Maryland, 22 South Greene St, Office T1R40, Baltimore, MD 21201. email: [email protected]
ª 2015 by the American College of Surgeons Published by Elsevier Inc.
762
http://dx.doi.org/10.1016/j.jamcollsurg.2014.12.051 ISSN 1072-7515/15
Vol. 220, No. 4, April 2015
Narayan et al
Abbreviations and Acronyms
APR_SOI DRG ED EGS HSCRC LOS NTC OR TC
¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼
All Patients Refined Severity of Illness diagnosis related group emergency department emergency general surgery Health Services Cost Review Commission length of stay nonetrauma center odds ratio trauma center
care surgery service is highly resource intensive and requires dedicated support staffing, intensive care, operating room availability, and a skilled surgical workforce.6 Hospitals with dedicated acute care surgery services have reported a shorter LOS and decreased time to operation, along with decreased morbidity for common emergency surgical procedures.7-12 As a result of the improved efficiency and quality of care, some have hypothesized that progression to EGS regionalization seems the logical next step.13,14 Currently, limited data exist defining the overall mortality of the EGS patient population. It is also unclear whether the existence of a designated TC has an impact on EGS outcomes. Given the considerable resources that inherently exist at designated TCs, we hypothesized that mortality would be lower for EGS patients treated at a TC vs NTC.
METHODS A retrospective review of the Maryland Health Services Cost Review Commission (HSCRC) database from 2009 to 2013 was performed. The Maryland HSCRC was created in the 1970s as a result of a waiver by the federal government exempting the state from national Medicare and Medicaid reimbursement principles.15 The HSCRC was mandated to review and approve reasonable hospital rates and publicly disclose information on the costs and financial performance of Maryland hospitals. Since its inception, all payers pay Maryland hospitals on the basis of the rates established by the HSCRC.16 The HSCRC Inpatient Data Set contains discharge medical record abstract and billing data on each of the state’s approximately 800,000 inpatient admissions annually. Hospitals submit data to the HSCRC on a quarterly basis. The HSCRC Research Data File was generated after approval by the HSCRC Review Board and confirmation of the Research Data Use Agreement. Analysis was performed using hospital discharge data from the HSCRC database, which provides information about the index hospital admission and is limited to 30 days
Mortality in Emergency General Surgery
763
of follow-up. The University of Maryland, Baltimore Internal Review Board approved the study. In 2013, the American Association for the Surgery of Trauma published its defined collection of EGS ICD-9 codes.17 From the HSCRC database, a patient was classified as an EGS patient if at least 1 of the 15 ICD-9 diagnosis codes recorded matched an American Association for the Surgery of Trauma EGS ICD-9 code. All adult patients aged 18 years or older were included in the analysis. Other variables collected included age, sex, race, hospital LOS, ICU LOS, emergency department (ED) admission, and All Patients Refined Severity of Illness (APR_SOI). Diagnosis related groups (DRGs), developed at Yale University in the 1960s, are a patient-classification method that provide a means of relating the type of patients a hospital treats (case mix) to costs incurred by that hospital. Three major versions of the DRG are currently in use: Basic DRGs, All Patient DRGs, and All Patient Refined DRGs. The Basic DRGs are used by the Centers for Medicare and Medicaid Services for hospital payment for Medicare beneficiaries. The All Patient DRGs expand on the Basic DRGs and are more representative of non-Medicare populations. The original objective of DRGs was to develop a patient classification system that related the types of patients treated to the resources they consumed. The DRGs focused exclusively on resource intensity. A new classification incorporating patient severity of illness and risk of mortality, in addition to resource use, was developed to enable comparison of hospitals across a wide range of resource and outcome measures. The All Patient Refined DRG incorporates severity of illness subclasses. The APR_SOI is defined by the extent of physiologic decompensation or organ system loss of function. The HSCRC database uses this definition to stratify patients into 4 levels based on severity of illness: minor, moderate, major, and extreme.15-18 Additional data collected included the nature of admission (emergent/urgent, or other). Hospitals were divided into TC vs NTC. The TC designation (Level I, II, or III) was obtained from the Maryland Institute for Emergency Medical Services Systems. Level I TCs are tertiary care facilities that are capable of providing comprehensive care of the trauma patient. These centers also provide prevention and rehabilitation resources. Staffing includes 24-hour in-house coverage by general surgeons and prompt availability of care in specialties such as orthopaedic surgery, neurosurgery, anesthesiology, emergency medicine, radiology, internal medicine, plastic surgery, oral and maxillofacial, pediatric, and critical care. Level II TCs are able to initiate definitive care for all injured patients. Staffing in this model includes 24-hour immediate coverage by general surgeons, as well as coverage by
764
Table 1.
Narayan et al
J Am Coll Surg
Mortality in Emergency General Surgery
Demographics of HCSCRC Database from 2009 to 2013
Variable
Population, n (%) Age, y, mean SD Sex, n (%) Male Female Unknown Race, n (%) White Black Other Hospital LOS, d, median (IQR) Hospital LOS, n (%) 0d 1e4 d >4 d LOS ICU, n (%) 0d 1 d ICU 1, d, median (IQR) ED admissions, n (%) Yes No APR_SOI, n (%) Minor Moderate Major Extreme Trauma level, n (%) None III II I
Total
Alive
Expired
p Value*
817,942 60.1 18.7
784,778 (95.95) 59.7 18.7
33,164 (4.05) 71.0 15.3
