265 C OPYRIGHT Ó 2015
BY
T HE J OURNAL
OF
B ONE
AND J OINT
S URGERY, I NCORPORATED
A commentary by James P. Stannard, MD, is linked to the online version of this article at jbjs.org.
The Impact of Trauma-Center Care on Mortality and Function Following Pelvic Ring and Acetabular Injuries Saam Morshed, MD, PhD, MPH, Simon Knops, MD, Gregory J. Jurkovich, MD, Jin Wang, PhD, Ellen MacKenzie, PhD, and Frederick P. Rivara, MD, MPH Investigation performed at the Orthopaedic Trauma Institute, Departments of Orthopaedic Surgery and of Epidemiology and Biostatistics, San Francisco General Hospital and University of California, San Francisco, California, and University of Washington School of Medicine, Seattle, Washington
Background: Lower mortality and improved physical function following major polytrauma have been associated with treatment at level-I trauma centers compared with that at hospitals without a trauma center (nontrauma centers). This study investigated the impact of trauma-center care on outcomes after pelvic and acetabular injuries. Methods: Mortality and quality-of-life-related scores were compared among patients treated in eighteen level-I trauma centers and fifty-one nontrauma centers in fourteen U.S. states. Complete data were obtained on 829 adult trauma patients (eighteen to eighty-four years old) who had at least one pelvic ring or acetabular injury (Orthopaedic Trauma Association [OTA] classification of 61 or 62). We used inverse probability of treatment weighting to adjust for observable confounding. Results: After adjusting for case mix, we found that, for patients with more severe acetabular injuries (OTA 62-B or 62-C), in-hospital mortality was significantly lower at trauma centers compared with nontrauma centers (relative risk [RR], 0.10; 95% confidence interval [CI], 0.02 to 0.47), as was death within ninety days (RR, 0.10; 95% CI, 0.02 to 0.47) and within one year (RR, 0.21; 95% CI, 0.06 to 0.76). Patients with combined pelvic ring and acetabular injuries treated at a trauma center had lower mortality at ninety days (RR, 0.34; 95% CI, 0.14 to 0.82) and at one year (RR, 0.30; 95% CI, 0.14 to 0.68). Care at trauma centers was also associated with mortality risk reduction for those with unstable pelvic ring injuries (OTA 61-B or 61-C) at one year (RR, 0.71; 95% CI, 0.24 to 0.91). Seventy-eight percent of included subjects discharged alive were available for interview at twelve months. For those with more severe acetabular injuries, average absolute differences in the Short Form-36 (SF-36) physical function component and the Musculoskeletal Function Assessment at one year were 11.4 (95% CI, 5.3 to 17.4) and 13.2 (1.7 to 24.7), respectively, indicating statistically and clinically significant improved outcomes following treatment at a trauma center for those patients. Conclusions: Mortality was reduced for patients with unstable pelvic and severe acetabular injuries when care was provided in a trauma center compared with a nontrauma center. Moreover, those with severe acetabular fractures experienced improved physical function at one year. Patients with these injuries represent a well-defined subset of trauma patients for whom our findings suggest preferential triage or transfer to a level-I trauma center. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Peer Review: This article was reviewed by the Editor-in-Chief and one Deputy Editor, and it underwent blinded review by two or more outside experts. It was also reviewed by an expert in methodology and statistics. The Deputy Editor reviewed each revision of the article, and it underwent a final review by the Editor-in-Chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and copyeditors.
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
J Bone Joint Surg Am. 2015;97:265-72
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http://dx.doi.org/10.2106/JBJS.N.00008
266 TH E JO U R NA L O F B O N E & JO I N T SU RG E RY J B J S . O RG V O L U M E 97-A N U M B E R 4 F E B R UA R Y 18, 2 015 d
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C
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ritically injured trauma patients benefit from an organized trauma service and integrated multidisciplinary care1. Efforts at regionalization of trauma care have been based on the premise that the concentration of resources for the delivery of this complex specialty care will result in improved outcomes2,3. However, the majority of studies supporting this notion have been retrospective studies of registry data4. The National Study on Costs and Outcomes of Trauma (NSCOT) is a prospective study that was initiated to examine variations in care across level-I trauma centers and hospitals without a trauma center (nontrauma centers), to identify predictors of outcomes, and to estimate cost-effectiveness of trauma care5. The study (by E.M., F.P.R, G.J.J., and colleagues), showed that the risk of death was significantly lower when care to critically injured patients was provided in a level-I trauma center than when provided in a nontrauma center6. Although this study also demonstrated modest benefits associated with treatment at a level-I trauma center in terms of the physical functioning of patients with a major lower-limb injury, a similar benefit in terms of mortality was not found among patients across the broad spectrum of orthopaedic injuries7. Patients with pelvic and acetabular injuries compose a subset of trauma patients with particularly high morbidity and mortality8-10. These injuries typically result from high-energy trauma and are often accompanied by severe hemorrhage and
I M PA C T O F T R AU M A C A R E O N M O R TA L I T Y A N D F U N C T I O N F O L L O W I N G P E LV I C A N D A C E TA B U L A R I N J U R I E S
other potential life-threatening injuries. Given the complexity and multimodal needs of trauma patients with pelvic and acetabular injuries compared with other extremity trauma, we hypothesized that such patients would show significant mortality and functional benefits from trauma-center care. We conducted a secondary analysis of the NSCOT data to assess both the effect on mortality and functional outcomes among patients who received trauma-center care, specifically those with pelvic and acetabular injuries. Materials and Methods he NSCOT was conducted in fifteen regions, defined by contiguous Metropolitan Statistical Areas in fourteen states, using sampling procedures that 5 have been previously described . The Metropolitan Statistical Areas were selected from among the twenty-five largest such areas in nineteen states; excluded were those in which large nontrauma centers collectively treated annually fewer than seventy-five patients with major traumatic injury (an Injury Severity Score of >15 derived by ICD-9-CM [International Classification of Diseases, Ninth Revision, 4 Clinical Modification] diagnostic codes) . Within each Metropolitan Statistical Area, all level-I trauma centers and large nontrauma centers were identified, as were large nontrauma centers that annually treated at least twenty-five patients with major traumatic injury. Of the trauma centers included, thirteen were designated as such by the state and ten were verified by the American College of Surgeons Committee on Trauma (ACSCOT); five were recognized by both the state and ACSCOT. Level-II and level-III centers were not included. Ultimately, eighteen trauma centers and fifty-one nontrauma centers agreed to participate and received institutional review board approval to do so.
T
Fig. 1
Flow of subject inclusion and follow-up. ED = emergency department, and MFA = Musculoskeletal Function Assessment.
267 TH E JO U R NA L O F B O N E & JO I N T SU RG E RY J B J S . O RG V O L U M E 97-A N U M B E R 4 F E B R UA R Y 18, 2 015 d
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d
I M PA C T O F T R AU M A C A R E O N M O R TA L I T Y A N D F U N C T I O N F O L L O W I N G P E LV I C A N D A C E TA B U L A R I N J U R I E S
TABLE I Patient Characteristics* Before Adjustment
No. of Patients (Unweighted)
Nontrauma Center N = 278 (N = 638 Weighted)
Trauma Center N = 551 (N = 2006 Weighted)
494 81 114 140
58.3 ± 33.4 35.6% 12.6% 17.3% 34.5%
40.0 ± 31.1 81.9% 8.9% 5.7% 3.5%
Sex Male Female
451 378
33.5% 66.5%
63.7% 36.3%
Race Hispanic Non-Hispanic, white Non-Hispanic, non-white
107 594 128
9.1% 81.9% 9.0%
17.9% 61.8% 20.3%
Insurance None Medicare only Medicare and private Private Medicaid Other
162 183 104 295 52 33
10.7% 38.2% 15.2% 26.4% 4.7% 4.9%
30.6% 6.9% 6.3% 46.3% 5.3% 4.6%
Injury mechanism Penetrating Blunt
35 794
3.1% 96.9%
5.5% 94.5%
First ED motor GCS 6 4, 5 2, 3 1 (not paralyzed) 1 (paralyzed)
636 50 13 49 81
93.3% 3.0% 0.4% 0.8% 2.5%
75.5% 7.3% 1.8% 4.2% 11.2%
Injury Severity Score Mean, SD 34
348 206 165 110
11.3 ±14.7 77.4% 12.7% 5.3% 4.6%
22.5 ± 22.3 34.6% 27.5% 22.9% 14.9%
Maximum AIS £3 4 5, 6
551 187 91
89.2% 7.7% 3.1%
63.6% 24.6% 11.8%
Maximum AIS ‡3 Head region Face region Thoracic region
164 23 319
8.2% 1.0% 14.7%
24.0% 3.3% 42.0%
After Adjustment
P Value
Nontrauma Center N = 278 (N = 2331 Weighted)
Trauma Center N = 551 (N = 2520 Weighted)
42.3 ± 63.3 68.2% 9.6% 9.0% 13.2%
42.2 ± 37.8 77.1% 9.2% 7.5% 6.2%
41.8% 58.2%
62.4% 37.6%
14.0% 70.5% 15.5%
16.2% 64.9% 18.9%
18.4% 16.3% 7.0% 41.5% 10.0% 6.8%
27.5% 10.5% 7.2% 45.4% 4.8% 4.6%
7.4% 92.6%
4.8% 95.2%
73.3% 4.3% 1.6% 1.5% 19.3%
78.5% 6.7% 1.6% 3.9% 9.3%
22.3 ± 44.8 42.0% 22.7% 10.3% 25.0%
21.0 ± 25.0 40.8% 25.8% 20.5% 12.9%
65.0% 17.1% 17.9%
67.4% 22.1% 10.5%
28.0% 3.0% 40.9%
21.7% 3.0% 37.9%
P Value
Age (yr) Mean, SD
BY
T HE J OURNAL
OF
B ONE
AND J OINT
S URGERY, I NCORPORATED
A commentary by James P. Stannard, MD, is linked to the online version of this article at jbjs.org.
The Impact of Trauma-Center Care on Mortality and Function Following Pelvic Ring and Acetabular Injuries Saam Morshed, MD, PhD, MPH, Simon Knops, MD, Gregory J. Jurkovich, MD, Jin Wang, PhD, Ellen MacKenzie, PhD, and Frederick P. Rivara, MD, MPH Investigation performed at the Orthopaedic Trauma Institute, Departments of Orthopaedic Surgery and of Epidemiology and Biostatistics, San Francisco General Hospital and University of California, San Francisco, California, and University of Washington School of Medicine, Seattle, Washington
Background: Lower mortality and improved physical function following major polytrauma have been associated with treatment at level-I trauma centers compared with that at hospitals without a trauma center (nontrauma centers). This study investigated the impact of trauma-center care on outcomes after pelvic and acetabular injuries. Methods: Mortality and quality-of-life-related scores were compared among patients treated in eighteen level-I trauma centers and fifty-one nontrauma centers in fourteen U.S. states. Complete data were obtained on 829 adult trauma patients (eighteen to eighty-four years old) who had at least one pelvic ring or acetabular injury (Orthopaedic Trauma Association [OTA] classification of 61 or 62). We used inverse probability of treatment weighting to adjust for observable confounding. Results: After adjusting for case mix, we found that, for patients with more severe acetabular injuries (OTA 62-B or 62-C), in-hospital mortality was significantly lower at trauma centers compared with nontrauma centers (relative risk [RR], 0.10; 95% confidence interval [CI], 0.02 to 0.47), as was death within ninety days (RR, 0.10; 95% CI, 0.02 to 0.47) and within one year (RR, 0.21; 95% CI, 0.06 to 0.76). Patients with combined pelvic ring and acetabular injuries treated at a trauma center had lower mortality at ninety days (RR, 0.34; 95% CI, 0.14 to 0.82) and at one year (RR, 0.30; 95% CI, 0.14 to 0.68). Care at trauma centers was also associated with mortality risk reduction for those with unstable pelvic ring injuries (OTA 61-B or 61-C) at one year (RR, 0.71; 95% CI, 0.24 to 0.91). Seventy-eight percent of included subjects discharged alive were available for interview at twelve months. For those with more severe acetabular injuries, average absolute differences in the Short Form-36 (SF-36) physical function component and the Musculoskeletal Function Assessment at one year were 11.4 (95% CI, 5.3 to 17.4) and 13.2 (1.7 to 24.7), respectively, indicating statistically and clinically significant improved outcomes following treatment at a trauma center for those patients. Conclusions: Mortality was reduced for patients with unstable pelvic and severe acetabular injuries when care was provided in a trauma center compared with a nontrauma center. Moreover, those with severe acetabular fractures experienced improved physical function at one year. Patients with these injuries represent a well-defined subset of trauma patients for whom our findings suggest preferential triage or transfer to a level-I trauma center. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Peer Review: This article was reviewed by the Editor-in-Chief and one Deputy Editor, and it underwent blinded review by two or more outside experts. It was also reviewed by an expert in methodology and statistics. The Deputy Editor reviewed each revision of the article, and it underwent a final review by the Editor-in-Chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and copyeditors.
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
J Bone Joint Surg Am. 2015;97:265-72
d
http://dx.doi.org/10.2106/JBJS.N.00008
266 TH E JO U R NA L O F B O N E & JO I N T SU RG E RY J B J S . O RG V O L U M E 97-A N U M B E R 4 F E B R UA R Y 18, 2 015 d
d
C
d
ritically injured trauma patients benefit from an organized trauma service and integrated multidisciplinary care1. Efforts at regionalization of trauma care have been based on the premise that the concentration of resources for the delivery of this complex specialty care will result in improved outcomes2,3. However, the majority of studies supporting this notion have been retrospective studies of registry data4. The National Study on Costs and Outcomes of Trauma (NSCOT) is a prospective study that was initiated to examine variations in care across level-I trauma centers and hospitals without a trauma center (nontrauma centers), to identify predictors of outcomes, and to estimate cost-effectiveness of trauma care5. The study (by E.M., F.P.R, G.J.J., and colleagues), showed that the risk of death was significantly lower when care to critically injured patients was provided in a level-I trauma center than when provided in a nontrauma center6. Although this study also demonstrated modest benefits associated with treatment at a level-I trauma center in terms of the physical functioning of patients with a major lower-limb injury, a similar benefit in terms of mortality was not found among patients across the broad spectrum of orthopaedic injuries7. Patients with pelvic and acetabular injuries compose a subset of trauma patients with particularly high morbidity and mortality8-10. These injuries typically result from high-energy trauma and are often accompanied by severe hemorrhage and
I M PA C T O F T R AU M A C A R E O N M O R TA L I T Y A N D F U N C T I O N F O L L O W I N G P E LV I C A N D A C E TA B U L A R I N J U R I E S
other potential life-threatening injuries. Given the complexity and multimodal needs of trauma patients with pelvic and acetabular injuries compared with other extremity trauma, we hypothesized that such patients would show significant mortality and functional benefits from trauma-center care. We conducted a secondary analysis of the NSCOT data to assess both the effect on mortality and functional outcomes among patients who received trauma-center care, specifically those with pelvic and acetabular injuries. Materials and Methods he NSCOT was conducted in fifteen regions, defined by contiguous Metropolitan Statistical Areas in fourteen states, using sampling procedures that 5 have been previously described . The Metropolitan Statistical Areas were selected from among the twenty-five largest such areas in nineteen states; excluded were those in which large nontrauma centers collectively treated annually fewer than seventy-five patients with major traumatic injury (an Injury Severity Score of >15 derived by ICD-9-CM [International Classification of Diseases, Ninth Revision, 4 Clinical Modification] diagnostic codes) . Within each Metropolitan Statistical Area, all level-I trauma centers and large nontrauma centers were identified, as were large nontrauma centers that annually treated at least twenty-five patients with major traumatic injury. Of the trauma centers included, thirteen were designated as such by the state and ten were verified by the American College of Surgeons Committee on Trauma (ACSCOT); five were recognized by both the state and ACSCOT. Level-II and level-III centers were not included. Ultimately, eighteen trauma centers and fifty-one nontrauma centers agreed to participate and received institutional review board approval to do so.
T
Fig. 1
Flow of subject inclusion and follow-up. ED = emergency department, and MFA = Musculoskeletal Function Assessment.
267 TH E JO U R NA L O F B O N E & JO I N T SU RG E RY J B J S . O RG V O L U M E 97-A N U M B E R 4 F E B R UA R Y 18, 2 015 d
d
d
I M PA C T O F T R AU M A C A R E O N M O R TA L I T Y A N D F U N C T I O N F O L L O W I N G P E LV I C A N D A C E TA B U L A R I N J U R I E S
TABLE I Patient Characteristics* Before Adjustment
No. of Patients (Unweighted)
Nontrauma Center N = 278 (N = 638 Weighted)
Trauma Center N = 551 (N = 2006 Weighted)
494 81 114 140
58.3 ± 33.4 35.6% 12.6% 17.3% 34.5%
40.0 ± 31.1 81.9% 8.9% 5.7% 3.5%
Sex Male Female
451 378
33.5% 66.5%
63.7% 36.3%
Race Hispanic Non-Hispanic, white Non-Hispanic, non-white
107 594 128
9.1% 81.9% 9.0%
17.9% 61.8% 20.3%
Insurance None Medicare only Medicare and private Private Medicaid Other
162 183 104 295 52 33
10.7% 38.2% 15.2% 26.4% 4.7% 4.9%
30.6% 6.9% 6.3% 46.3% 5.3% 4.6%
Injury mechanism Penetrating Blunt
35 794
3.1% 96.9%
5.5% 94.5%
First ED motor GCS 6 4, 5 2, 3 1 (not paralyzed) 1 (paralyzed)
636 50 13 49 81
93.3% 3.0% 0.4% 0.8% 2.5%
75.5% 7.3% 1.8% 4.2% 11.2%
Injury Severity Score Mean, SD 34
348 206 165 110
11.3 ±14.7 77.4% 12.7% 5.3% 4.6%
22.5 ± 22.3 34.6% 27.5% 22.9% 14.9%
Maximum AIS £3 4 5, 6
551 187 91
89.2% 7.7% 3.1%
63.6% 24.6% 11.8%
Maximum AIS ‡3 Head region Face region Thoracic region
164 23 319
8.2% 1.0% 14.7%
24.0% 3.3% 42.0%
After Adjustment
P Value
Nontrauma Center N = 278 (N = 2331 Weighted)
Trauma Center N = 551 (N = 2520 Weighted)
42.3 ± 63.3 68.2% 9.6% 9.0% 13.2%
42.2 ± 37.8 77.1% 9.2% 7.5% 6.2%
41.8% 58.2%
62.4% 37.6%
14.0% 70.5% 15.5%
16.2% 64.9% 18.9%
18.4% 16.3% 7.0% 41.5% 10.0% 6.8%
27.5% 10.5% 7.2% 45.4% 4.8% 4.6%
7.4% 92.6%
4.8% 95.2%
73.3% 4.3% 1.6% 1.5% 19.3%
78.5% 6.7% 1.6% 3.9% 9.3%
22.3 ± 44.8 42.0% 22.7% 10.3% 25.0%
21.0 ± 25.0 40.8% 25.8% 20.5% 12.9%
65.0% 17.1% 17.9%
67.4% 22.1% 10.5%
28.0% 3.0% 40.9%
21.7% 3.0% 37.9%
P Value
Age (yr) Mean, SD
