Association of Police Transport With Survival Among Patients With Penetrating Trauma in Philadelphia, Pennsylvania | Emergency Medicine | JAMA Network Open | JAMA Network
[Skip to Navigation]
Sign In
Figure 1.  Overview of Patient Matching and Analysis
Overview of Patient Matching and Analysis

A, Schematic of the process used for whole cohort analysis, coarsened exact matching, and matched cohort analysis. B, Record of patients removed from sample before analysis. C, Coarsened exact matching criteria used to match patients. EMS indicates emergency medical services; GCS, Glasgow Coma Scale; and SBP, systolic blood pressure.

Figure 2.  Matched Cohort Outcomes
Matched Cohort Outcomes

A, Odds ratios (ORs) and 95% CIs for matched cohort patient outcomes at several different time points after trauma center arrival. B, ORs and 95% CIs for matched cohort patient outcomes with different Injury Severity Scores (ISS) at several different time points after trauma center arrival.

Table 1.  Characteristics of Patients
Characteristics of Patients
Table 2.  Matched Cohort Outcomes
Matched Cohort Outcomes
Table 3.  Matched Cohort Injury Severity and Mortality
Matched Cohort Injury Severity and Mortality
1.
Centers for Disease Control and Prevention. WISQARS fatal injury reports, national, regional, and state, 1981-2018. Accessed June 28, 2020. https://webappa.cdc.gov/sasweb/ncipc/mortrate.html
2.
Sakran  JV, Mehta  A, Fransman  R,  et al.  Nationwide trends in mortality following penetrating trauma: are we up for the challenge?   J Trauma Acute Care Surg. 2018;85(1):160-166. doi:10.1097/TA.0000000000001907 PubMedGoogle ScholarCrossref
3.
Gramlich M. What the data says about gun deaths in the U.S. Pew Research Center. Accessed August 30, 2019. https://www.pewresearch.org/fact-tank/2019/08/16/what-the-data-says-about-gun-deaths-in-the-u-s/
4.
Alarhayem  AQ, Myers  JG, Dent  D,  et al.  Time is the enemy: mortality in trauma patients with hemorrhage from torso injury occurs long before the “golden hour”.   Am J Surg. 2016;212(6):1101-1105. doi:10.1016/j.amjsurg.2016.08.018 PubMedGoogle ScholarCrossref
5.
Harmsen  AMK, Giannakopoulos  GF, Moerbeek  PR, Jansma  EP, Bonjer  HJ, Bloemers  FW.  The influence of prehospital time on trauma patients outcome: a systematic review.   Injury. 2015;46(4):602-609. doi:10.1016/j.injury.2015.01.008 PubMedGoogle ScholarCrossref
6.
Rappold  JF, Hollenbach  KA, Santora  TA,  et al.  The evil of good is better: making the case for basic life support transport for penetrating trauma victims in an urban environment.   J Trauma Acute Care Surg. 2015;79(3):343-348. doi:10.1097/TA.0000000000000783 PubMedGoogle ScholarCrossref
7.
Jacoby  SF, Reeping  PM, Branas  CC.  Police-to-hospital transport for violently injured individuals: a way to save lives?   Ann AAPSS. 2020;687(1):186-201. doi:10.1177/0002716219891698 Google ScholarCrossref
8.
Branas  CC, Sing  RF, Davidson  SJ.  Urban trauma transport of assaulted patients using nonmedical personnel.   Acad Emerg Med. 1995;2(6):486-493. doi:10.1111/j.1553-2712.1995.tb03245.x PubMedGoogle ScholarCrossref
9.
Band  RA, Salhi  RA, Holena  DN, Powell  E, Branas  CC, Carr  BG.  Severity-adjusted mortality in trauma patients transported by police.   Ann Emerg Med. 2014;63(5):608-614.e3. doi:10.1016/j.annemergmed.2013.11.008 PubMedGoogle ScholarCrossref
10.
Wandling  MW, Nathens  AB, Shapiro  MB, Haut  ER.  Police transport versus ground EMS: a trauma system–level evaluation of prehospital care policies and their effect on clinical outcomes.   J Trauma Acute Care Surg. 2016;81(5):931-935. doi:10.1097/TA.0000000000001228 PubMedGoogle ScholarCrossref
11.
Philadelphia Police Department. Directive 3.14. Published online July 20, 2018. Accessed May 3, 2020. https://www.phillypolice.com/assets/directives/D3.14-HospitalCases.pdf
12.
van Brocklin  E. “Scoop and run” can save lives: why don’t more police departments try it? The Trace. Published November 19, 2018. Accessed May 23, 2020. https://www.thetrace.org/2018/11/scoop-and-run-gunshot-victim-police-transport/
13.
Detroit Police Department. Transport policy. Accessed May 23, 2020. https://drive.google.com/file/d/1uZdfxwSFuCmQ8xPwf-9zNq9s7tGdA1v_/view?usp=embed_facebook
14.
Pennsylvania Trauma Systems Foundation. About. Accessed May 3, 2020. http://ptsf.org/registry/about
15.
Baker  SP, O’Neill  B.  The Injury Severity Score: an update.   J Trauma. 1976;16(11):882-885. doi:10.1097/00005373-197611000-00006 PubMedGoogle ScholarCrossref
16.
Pal  J, Brown  R, Fleiszer  D.  The value of the Glasgow Coma Scale and Injury Severity Score: predicting outcome in multiple trauma patients with head injury.   J Trauma. 1989;29(6):746-748. doi:10.1097/00005373-198906000-00008 PubMedGoogle ScholarCrossref
17.
Gill  M, Windemuth  R, Steele  R, Green  SM.  A comparison of the Glasgow Coma Scale score to simplified alternative scores for the prediction of traumatic brain injury outcomes.   Ann Emerg Med. 2005;45(1):37-42. doi:10.1016/j.annemergmed.2004.07.429 PubMedGoogle ScholarCrossref
18.
Champion  HR, Sacco  WJ, Copes  WS, Gann  DS, Gennarelli  TA, Flanagan  ME.  A revision of the Trauma Score.   J Trauma. 1989;29(5):623-629. doi:10.1097/00005373-198905000-00017 PubMedGoogle ScholarCrossref
19.
Fay  MP, Hunsberger  SA, Nason  M, Gabriel  E, Lumbard  K. exact2x2: Exact tests and confidence intervals for 2x2 tables. Accessed June 15, 2020. https://cran.r-project.org/web/packages/exact2x2/index.html
20.
Sjölander  A, Greenland  S.  Ignoring the matching variables in cohort studies—when is it valid and why?   Stat Med. 2013;32(27):4696-4708. doi:10.1002/sim.5879 PubMedGoogle ScholarCrossref
21.
SAS Institute Inc. Analytics software & solutions. Accessed June 28, 2020. https://www.sas.com/en_us/home.html
22.
The R Project for Statistical Computing. Getting started. Accessed June 28, 2020. https://www.r-project.org/
23.
Ho  D, Imai  K, King  G, Stuart  EA.  MatchIt: nonparametric preprocessing for parametric causal inference.   J Stat Softw. 2011;42(1):1-28. doi:10.18637/jss.v042.i08 PubMedGoogle Scholar
24.
Fay  MP, Hunsberger  SA, Nason  M, Gabriel  E, Lumbard  K. exact2x2: Exact tests and confidence intervals for 2x2 tables. 2019. Accessed June 15, 2020. https://CRAN.R-project.org/package=exact2x2
25.
Crandall  M, Sharp  D, Unger  E,  et al.  Trauma deserts: distance from a trauma center, transport times, and mortality from gunshot wounds in Chicago.   Am J Public Health. 2013;103(6):1103-1109. doi:10.2105/AJPH.2013.301223 PubMedGoogle ScholarCrossref
26.
Tung  EL, Hampton  DA, Kolak  M, Rogers  SO, Yang  JP, Peek  ME.  Race/ethnicity and geographic access to urban trauma care.   JAMA Netw Open. 2019;2(3):e190138. doi:10.1001/jamanetworkopen.2019.0138 PubMedGoogle Scholar
27.
Johnson  KE.  Police–Black community relations in postwar Philadelphia: race and criminalization in urban social spaces, 1945-1960.   J Afr Am Hist. 2004;89(2):118-134. doi:10.2307/4134096 Google Scholar
28.
Brunson  RK, Miller  J.  Young Black men and urban policing in the United States.   Br J Criminol. 2006;46(4):613-640. doi:10.1093/bjc/azi093 Google ScholarCrossref
29.
Jacoby  SF, Richmond  TS, Holena  DN, Kaufman  EJ.  A safe haven for the injured? urban trauma care at the intersection of healthcare, law enforcement, and race.   Soc Sci Med. 2018;199:115-122. doi:10.1016/j.socscimed.2017.05.037 PubMedGoogle ScholarCrossref
30.
Busch  J.  Shots fired: when a police car becomes an ambulance: in Philadelphia cops can transport penetrating-trauma patients; will other systems follow suit?   EMS World. 2013;42(5):I8.PubMedGoogle Scholar
31.
Iacus  SM, King  G, Porro  G.  Causal inference without balance checking: coarsened exact matching.   Political Analysis. 2012;20(01):1-24. doi:10.1093/pan/mpr013 Google ScholarCrossref
32.
Holcomb  JB.  Transport time and preoperating room hemostatic interventions are important: improving outcomes after severe truncal injury.   Crit Care Med. 2018;46(3):447-453. doi:10.1097/CCM.0000000000002915 PubMedGoogle ScholarCrossref
Limit 200 characters
Limit 25 characters
Conflicts of Interest Disclosure

Identify all potential conflicts of interest that might be relevant to your comment.

Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.

Err on the side of full disclosure.

If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.

Not all submitted comments are published. Please see our commenting policy for details.

Limit 140 characters
Limit 3600 characters or approximately 600 words
    1 Comment for this article
    EXPAND ALL
    EMS Doing Their Jobs
    Errington Thompson, MD | Marshall University
    I enjoyed reading, “Association of Police Transport With Survival Among Patients With Penetrating Trauma in Philadelphia, Pennsylvania.1” Winter and colleagues are to be congratulated. Their study includes a cohort of over 3300 patients. They conclude that for penetrating trauma in an urban setting, 24-hour mortality is no different between police transport versus EMS transport. Is this surprising?
    In 1994, Mattox and colleagues revealed that patients with penetrating torso trauma did not require fluid resuscitation prior to operative intervention.2 To further emphasize the role of prehospital care, the surgeons at LA County investigated over 5000 trauma patients.3 They compared patients who
    were brought into the ER via EMS versus those who are brought in via private vehicle. They found that the EMS group had twice the mortality rate of the non-EMS group. The beauty of these investigators is that they did not stop there. The authors further asked, why was mortality higher in the EMS group? In a subsequent study, the authors compared transport times between the EMS group and the non-EMS group.4 (The authors had to extrapolate the transport times for the non-EMS group.) Although the transport times were similar, the scene times were significantly higher for EMS. Here was the problem. EMS techs were trained. Scene times were decreased and the mortality rate dropped also.
    Patients with penetrating trauma need to be transported to the operating room for definitive care as quickly as possible. Exceptions to this rule include patients with extremity vascular injuries who could benefit from a life-saving tourniquet or a needle decompression of a tension pneumothorax. EMS can also provide a life-saving airway when necessary.
    In a 1983 article, Frank Lewis stated, “in an urban environment, when time to the nearest hospital is 5-15 minutes, it is extremely doubtful that paramedic services will be beneficial.5” The current study should not be interpreted as the police have some magic power. They do not. They are good Samaritans, grabbing the victim of penetrating trauma and taking them to the nearest facility as quickly as possible. In light of the data from the current study, Philadelphia EMS should also be commended. They are getting patients with penetrating trauma to the appropriate facilities as quickly as humanly possible. Simply put, they are doing their job.
    1. Winter E, Hynes AM, Shultz K, Holena DN, Malhotra NR, Cannon JW. Association of Police Transport With Survival Among Patients With Penetrating Trauma in Philadelphia, Pennsylvania. JAMA Netw Open. 2021;4(1):e2034868. doi:10.1001/jamanetworkopen.2020.34868
    2. Bickell WH, Wall Jr MJ, Pepe PE, Martin RR, Ginger VF, Allen MK, Mattox KL. Immediate Versus Delayed Fluid Resuscitation for Hypotensive Patients With Penetrating Torso Injuries. New England Journal of Medicine. 1994 Oct 27;331(17):1105–9.
    3. Demetriades D, Chan L, Cornwell E, Belzberg H, Berne TV, Asensio J, Chan D, Eckstein M, Alo K. Paramedic vs Private Transportation of Trauma Patients: Effect on Outcome. Arch Surg. 1996;131(2):133–138. doi:10.1001/archsurg.1996.01430140023007
    4. Cornwell EE, Belzberg H, Hennigan K, Maxson C, Montoya G, Rosenbluth A, Velmahos GC, Berne TC, Demetriades D. Emergency Medical Services (EMS) vs Non-EMS Transport of Critically Injured Patients: A Prospective Evaluation. Arch Surg. 2000;135(3):315–319. doi:10.1001/archsurg.135.3.315
    5. Lewis FR, Aprahamian C, Haller JA, Jacobs LM, Luterman A, Border JR. Panel: Prehospital Trauma Care—Stabilize or Scoop and Run. The Journal of Trauma. 1983;23:708–1
    CONFLICT OF INTEREST: None Reported
    READ MORE
    Original Investigation
    Public Health
    January 25, 2021

    Association of Police Transport With Survival Among Patients With Penetrating Trauma in Philadelphia, Pennsylvania

    Author Affiliations
    • 1Division of Traumatology, Surgical Critical Care and Emergency Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia
    • 2The West Chester Statistical Institute, Department of Mathematics, West Chester University, West Chester, Pennsylvania
    • 3McKenna EpiLog Fellowship in Population Health, University of Pennsylvania, Philadelphia
    • 4Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia
    • 5Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia
    JAMA Netw Open. 2021;4(1):e2034868. doi:10.1001/jamanetworkopen.2020.34868
    Key Points

    Question  Is police-based transport of patients with penetrating trauma associated with lower 24-hour mortality than emergency medical services (EMS)–based transport?

    Findings  In this cohort study of 3313 patients with penetrating trauma, individuals with similar injury mechanism and severity had similar 24-hour mortality when transported by police compared with EMS. Patients with the most severe injuries were more likely to be alive on arrival to the hospital when transported by police.

    Meaning  The results of this investigation suggest that police transport is safe and effective for patients with penetrating trauma, with equivalent mortality outcomes compared with traditional EMS transport.

    Abstract

    Importance  Police in Philadelphia, Pennsylvania, routinely transport patients with penetrating trauma to nearby trauma centers. During the past decade, this practice has gained increased acceptance, but outcomes resulting from police transport of these patients have not been recently evaluated.

    Objective  To assess mortality among patients with penetrating trauma who are transported to trauma centers by police vs by emergency medical services (EMS).

    Design, Setting, and Participants  This cohort study used the Pennsylvania Trauma Outcomes Study registry and included 3313 adult patients with penetrating trauma from January 1, 2014, to December 31, 2018. Outcomes were compared between patients transported by police (n = 1970) and patients transported by EMS (n = 1343) to adult level I and II trauma centers in Philadelphia.

    Exposures  Police vs EMS transport.

    Main Outcomes and Measures  The primary end point was 24-hour mortality. Secondary end points included death at multiple other time points. After whole-cohort regression analysis, coarsened exact matching was used to control for confounding differences between groups. Matching criteria included patient age, injury mechanism and location, Injury Severity Score (ISS), presenting systolic blood pressure, and Glasgow Coma Scale score. Subgroup analysis was performed among patients with low, moderate, or high ISS.

    Results  Of the 3313 patients (median age, 29 years [interquartile range, 23-40 years]) in the study, 3013 (90.9%) were men. During the course of the study, the number of police transports increased significantly (from 328 patients in 2014 to 489 patients in 2018; P = .04), while EMS transport remained unchanged (from 246 patients in 2014 to 281 patients in 2018; P = .44). On unadjusted analysis, compared with patients transported by EMS, patients transported by police were younger (median age, 27 years [interquartile range, 22-36 years] vs 32 years [interquartile range, 24-46 years]), more often injured by a firearm (1741 of 1970 [88.4%] vs 681 of 1343 [50.7%]), and had a higher median ISS (14 [interquartile range, 9-26] vs 10 [interquartile range, 5-17]). Patients transported by police had higher mortality at 24 hours than those transported by EMS (560 of 1970 [28.4%] vs 246 of 1343 [18.3%]; odds ratio, 1.86; 95% CI, 1.57-2.21; P < .001) and at all other time points. After coarsened exact matching (870 patients in each transport cohort), there was no difference in mortality at 24 hours (210 [24.1%] vs 212 [24.4%]; odds ratio, 0.95; 95% CI, 0.59-1.52; P = .91) or at any other time point. On subgroup analysis, patients with severe injuries transported by police were less likely to be dead on arrival compared with matched patients transported by EMS (64 of 194 [33.0%] vs 79 of 194 [40.7%]; odds ratio, 0.48; 95% CI, 0.24-0.94; P = .03).

    Conclusions and Relevance  For patients with penetrating trauma in an urban setting, 24-hour mortality was not different for those transported by police vs EMS to a trauma center. Timely transport to definitive trauma care should be emphasized over medical capability in the prehospital management of patients with penetrating trauma.

    Introduction

    Penetrating injuries cause more than 42 000 deaths in the United States annually.1 Despite recent advances in hospital-based resuscitation practices associated with improved survival, prehospital deaths from penetrating trauma have increased steadily since 2007.2,3 The time required to transport patients with penetrating trauma to the hospital is significantly associated with mortality, and rapid transport should be prioritized over field-based advanced life support interventions in critically injured patients with penetrating trauma.4-6

    Although emergency medical services (EMS) personnel typically perform prehospital medical care and provide rapid transport to the hospital, police officers may also be able to provide safe hospital transport for patients with life-threatening penetrating injuries. At a time when social activists are pushing to redefine the scope and objective of policing activities, a first-responder care role for police officers may also build trust between local communities and law enforcement officials.7

    In 1996, a policy directive in Philadelphia, Pennsylvania, instructed police officers to transport patients with serious penetrating wounds directly to accredited trauma centers and advised that transport should not be delayed to await the arrival of EMS.7-10 The Philadelphia Police Department has since become an essential partner in the care of individuals with penetrating trauma in the city and a model for other police transport programs throughout the country.10-12 Although other cities (including Chicago, Illinois; Cleveland, Ohio; Detroit, Michigan; and Sacramento, California) have subsequently implemented policies permitting police transport of injured individuals, Philadelphia remains the only major urban center to routinely use this practice.7,10,12,13

    Before such policies are implemented more broadly, patient volumes and outcomes should be assessed in detail. Past work has suggested that patients with penetrating trauma transported by police have shorter prehospital times relative to those transported by EMS.8 Other studies have shown that risk-adjusted mortality is not different between patients transported by police compared with those transported by EMS.8-10 Based on this evidence, the rate of police transport of patients with penetrating trauma in Philadelphia has significantly increased in recent years. The present study hypothesizes that patients with similar injuries transported to level I and level II trauma centers in Philadelphia by police have lower 24-hour mortality than patients transported by EMS.

    Methods
    Sample Selection and Definitions

    This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines. Patients with penetrating trauma transported by police or EMS directly to a level I or a level II trauma center in Philadelphia from January 1, 2014, to December 31, 2018, were identified in the Pennsylvania Trauma Outcomes Study (PTOS) registry (Figure 1A).14 Patients younger than 18 years, pregnant patients, incarcerated patients, those transported by private vehicle or by walk-in, and those transferred from other facilities were excluded (Figure 1B). This study was approved by the University of Pennsylvania institutional review board with a waiver of informed consent because this project involved secondary analysis of existing data, with all human protections and data safety measures in place.

    Patients were divided into cohorts based on mode of transport (police vs EMS). Emergency medical services was defined as ground transport by either fire rescue paramedics or other non–fire rescue ambulance. Demographics, injury characteristics, and presenting physiological characteristics were compared between cohorts. Demographics included sex, race/ethnicity, and age. Injury characteristics included Injury Severity Score (ISS; range, 1-75, where 1 indicates a minor injury in a single body region and 75 indicates severe injuries in 3 separate body regions or ≥1 unsurvivable injury), penetrating mechanism, and isolated extremity injury. Penetrating mechanism was defined as an injury with a firearm or cutting instrument, while an isolated extremity injury was defined as patients with only an ISS in body region 5 (extremity) and no other region. Presenting physiological characteristics included Glasgow Coma Scale (GCS) score (range, 3-15, where 3 indicates absent eye opening and no verbal or motor response and 15 indicates spontaneously open eyes with normal verbal and motor function) and initial systolic blood pressure (SBP).

    Matched Cohort Creation

    After initial whole cohort analysis, patient characteristics including age, mechanism and location of injury, ISS, presenting GCS score, and SBP were used as matching criteria for coarsened exact matching (Figure 1C). Matching criteria were chosen based on prior work associating these factors with patient outcomes in penetrating trauma.15-18 Data were manually partitioned (“coarsened”) to create discrete categories within each matching criterion.

    Matches were sought between patients with different transport methods (police vs EMS) but with an otherwise identical combination of matching criteria strata. Unmatched patients were removed from the data set and were not subjected to further analysis. The resulting matched groups differed only with respect to transport method and had otherwise matched patient composition.

    Sensitivity Analysis and Subgroups

    Patients declared dead on arrival were identified for sensitivity analysis to evaluate if removal of these patients from the cohort altered the study findings. Subgroups were defined for patients with different levels of ISS and different types of EMS transport. Injury Severity Scores were divided into low (ISS, 1-8), moderate (ISS, 9-25), and high (ISS, 26-75) levels of injury. Emergency meical services transport was divided into those transported by fire rescue and ambulance.

    Statistical Analysis

    Transport volume was assessed using descriptive statistics and linear regression over time. For patient characteristics, categorical variables were compared using the χ2 test, and continuous variables were evaluated using the Wilcoxon-Mann-Whitney test.

    Whole cohort mortality at 24 hours (primary end point) and all other times was evaluated with univariate logistic regression. Matched cohort mortality at all time points was evaluated by use of the exact McNemar test19 and also by use of conditional logistic regression to permit explicit control of the matching terms.20 Kaplan-Meier analysis was used to compare outcomes over time in both the whole and matched cohorts.

    Data were assessed using SAS, version 9.4 (SAS Institute Inc),21 R, version 3.5.2 (R Foundation for Statistical Computing),22 and STATA, version 15 (StataCorp LLC). Matching was completed using the MatchIt package,23 and the exact McNemar test was completed using the exact2x2 package24 in R. Conditional logistic regression was performed with the STATA clogit package. All P values were from 2-sided tests and results were deemed statistically significant at P < .05.

    Results

    From 2014 to 2018, a total of 5620 patients with penetrating trauma were included in the PTOS data set—of these, 3485 met initial inclusion criteria, and 3313 were considered for analysis after detailed data review. A total of 3013 patients (90.9%) were men, and the median age was 29 years (interquartile range [IQR], 23-40 years). Of a total of 1343 (40.5%) in the EMS cohort, 1205 patients (36.4%) were transported directly to a trauma center by fire rescue and 138 patients (4.2%) were transported by ambulance. During this time, 1970 patients (59.5%) were transported by police; the annual rate of police transport was significantly higher than EMS transport (median, 382 of 651 [58.7%; IQR, 57.1%-60.6%] vs 269 of 651 [41.3%; IQR, 39.4%-42.9%]; P = .002). During the course of the study, the number of EMS transports remained relatively constant (from 246 patients in 2014 to 281 patients in 2018; P = .44), while the number of police transports increased significantly (from 328 patients in 2014 to 489 patients in 2018; P = .04) (eFigure 1 in the Supplement).

    Characteristics of Patients

    In the prematch sample (n = 3313), the median ISS was 10 (IQR, 6-25), the median GCS score was 15 (IQR, 6-15), and the median SBP was 120 mm Hg (IQR, 82-142 mm Hg). Patients transported by police (n = 1970) had a median age of 27 years (IQR, 22-36 years), a median ISS of 14 (IQR, 9-26), a median GCS score of 15 (IQR, 3-15), and a median SBP of 112 mm Hg (IQR, 70-140 mm Hg); 1741 (88.4%) had been injured by a firearm. Patients transported by EMS (n = 1343) had a median age of 32 years (IQR, 24-46 years), a median ISS of 10 (IQR, 5-17), a median GCS score of 15 (IQR, 14-15), and a median SBP of 126 mm Hg (IQR, 98-145 mm Hg); 681 [50.7%] had been injured by a firearm. These values were all significantly different between the 2 cohorts (all P < .001) (Table 1).

    Whole Cohort Outcomes

    In the prematch unadjusted sample, patients with penetrating trauma transported by police had significantly higher mortality at 24 hours than those transported by EMS (560 of 1970 [28.4%] vs 236 of 1343 [17.6%]; odds ratio [OR], 1.86; 95% CI, 1.57-2.21; P < .001) and at all other time points (eFigure 2A and eTable 1 in the Supplement). On Kaplan-Meier analysis, 28-day survival was significantly lower for police-transported patients, with the greatest divergence in survival occurring within the first 24 hours (eFigure 3A in the Supplement). Sensitivity analysis conducted after excluding patients dead on arrival in the police cohort (n = 334) and EMS cohort (n = 150) likewise demonstrated higher mortality in police-transported patients. No patients identified as having an isolated extremity injury expired before or during hospitalization in either transport group (police, 133; and EMS, 97). On subgroup analysis, patients transported by police were also found to have significantly greater mortality than patients transported by fire rescue or ambulance, at all studied time points (eTable 2 and eTable 3 in the Supplement).

    Injury severity scores for patients transported by police were significantly higher than those of patients transported by EMS. Patients transported by police with low (ISS, 1-8) and moderate (ISS, 9-25) injury severity had significantly higher 24-hour mortality compared with patients transported by EMS. This difference was not observed for patients with severe injuries (ISS, 26-75) (eFigure 2B and eTable 4 in the Supplement). There was no difference in mortality on arrival between patients transported by police vs EMS at any ISS level. The association between ISS and mortality was also assessed at other time points (eTable 4 in the Supplement).

    Matched Cohort Outcomes

    Coarsened exact matching identified 870 patients in each transport group (police vs EMS) with an identical combination of matching criteria (Table 1). Patients with penetrating trauma transported by police did not have significantly different mortality from those transported by EMS at 24 hours (210 [24.1%] vs 212 [24.4%]; OR, 0.95; 95% CI, 0.59-1.52; P = .91) (Figure 2A; Table 2). This finding was robust to explicit control of the matching terms using conditional logistic regression. Likewise, no significant difference in mortality between the police and EMS cohorts was observed for matched patients overall (238 [27.4%] vs 230 [26.4%]; P = .37), on arrival (123 [14.1%] vs 138 [15.9%]; P = .12), or at 1 hour (149 [17.1%] vs 161 [18.5%]; P = .20) or 6 hours (187 [21.5%] vs 193 [22.2%]; P = .56) after arrival. On Kaplan-Meier analysis, 28-day survival was not different between transport groups (eFigure 3B in the Supplement). Sensitivity analysis excluding matched patients who were dead on arrival after police transport (n = 123) or EMS transport (n = 138) likewise showed no difference in mortality (OR, 1.55; 95% CI, 0.88-2.77; P = .14). On subgroup analysis dividing patients transported by EMS into those transported by fire rescue and ambulance, there was no significant difference in mortality for either subgroup compared with police transport, at all studied time points (eTable 2 and eTable 3 in the Supplement).

    No difference in 24-hour mortality was observed for matched patients transported by police vs those transported by EMS with any level of injury severity (ISS 1-8: OR, 1.00 [95% CI, 0.01-78.50]; P > .99; ISS 9-25: OR, 1.15 [95% CI, 0.51-2.64]; P = .85; and ISS 26-75: OR, 0.85 [95% CI, 0.46-1.55]; P = .67) (Figure 2B; Table 3). In addition, no difference in mortality on arrival was observed for matched patients with low or moderate injury severity (ISS 1-8: OR, 0.50 [95% CI, 0.05-3.49]; P = .69; ISS 9-25: OR, 1.14 [95% CI, 0.52-2.53]; P = .86); however, patients with severe injuries had significantly lower mortality on arrival when transported by police (ISS 26-75: 64 of 194 [33.0%] vs 79 of 194 [40.7%]; OR, 0.48 [95% CI, 0.24-0.94]; P = .03). The association between ISS and mortality was also assessed at other time points (Table 3).

    Discussion

    This retrospective analysis demonstrates that police officers in Philadelphia transport most patients with penetrating trauma in the city, and between 2014 and 2018, police transport volume increased significantly while EMS transport volume remained relatively unchanged. Patients transported by police were younger, more likely to have been injured by a firearm, more severely injured, and more likely to have hypotension on hospital arrival compared with those transported by EMS. Patients transported by police had significantly higher unadjusted mortality at 24 hours and other secondary time points, relative to those transported by EMS.

    Coarsened exact matching was used to attenuate demographic differences between transport groups and control variables associated with injury mechanism and severity. Analysis of matched cohorts revealed no difference in mortality between transport groups at any studied time point. Severely injured patients (ISS 26-75) transported by police were more likely to be alive on arrival to a designated trauma center compared with severely injured patients transported by EMS.

    These results are largely consistent with those of prior investigations assessing police vs EMS transport of patients with penetrating trauma.8-10 One study focused on individuals with proximal penetrating trauma in Philadelphia, and found that overall mortality was significantly higher for patients transported by police compared with those transported by EMS.9 Risk-adjusted models showed no difference in mortality between transport groups and subgroup analysis suggested that patients with severe injuries (ISS 15-75) transported by police had lower overall mortality than patients with severe injuries transported by EMS. A nationwide study comparing 2467 police transports and 86 097 EMS transports of patients with penetrating trauma from 2010 to 2012 similarly found no difference in overall survival on risk-adjusted analysis.10

    Despite evidence demonstrating similar outcomes for patients transported by police and EMS, police transport remains relatively uncommon nationally. Analysis of the National Trauma Data Bank found that only 3% of patients with penetrating trauma were transported by police, and 88% of these transports occurred in Philadelphia (61%), Sacramento (21%), or Detroit (6%).10 Although a growing number of cities recognize the utility and safety of this approach, potential barriers to widespread adoption of police transport policies include logistical complexity, officer safety concerns, and scope-of-work issues.7

    Even though police transport may not be feasible in every area, some locations (such as New York, New York; Chicago, Illinois; and Los Angeles, California) have relatively higher rates of gun violence and longer travel times to designated trauma centers.7,25,26 Evidence suggests that “trauma deserts” in these cities are more likely to affect predominately Black neighborhoods, suggesting a possible disparity in access to timely trauma care.26 In such areas, law enforcement first responders may be able to improve outcomes by transporting patients with penetrating trauma to trauma centers without waiting for paramedics to arrive and administer potentially ineffective, nonhemostatic interventions at the scene.6,7

    Police transport policies may also have an impact beyond improving outcomes for patients with penetrating trauma. Evidence from past investigations and the present work suggests that most patients transported by police are young Black men, who are often injured in areas with historically adversarial relationships between residents and law enforcement.7,27,28 In some cases, injured Black individuals transported by police report appreciating the improved scene safety and expedited hospital transport facilitated by responding officers.29 Moreover, police transport may help diffuse scene anxiety and allay panic by responding to bystander requests for immediate assistance.7,30 Police transport programs thus have the potential to change established negative perceptions of law enforcement by demonstrating altruistic attributes of the police in their neighborhoods.7,29 Although police transport policies should be considered primarily through the lens of patient outcomes, the positive association of such policies with community dynamics may serve to lower actual or perceived barriers to implementation.

    Coarsened Exact Matching

    This study used coarsened exact matching. This statistical method retains the full dimensionality of each patient’s information such that patients are paired only when they “exactly match” on all individual matching criteria. Compared with other matching strategies, coarsened exact matching is able to independently control for many potential confounding variables associated with injury mechanism and severity.31 The matching criteria used in the present work were selected based on past work correlating patient age, ISS, GCS score, and SBP with patient outcomes.15-18

    Limitations

    In addition to the limitations inherent in a retrospective registry-based study, the results of the present work should be interpreted in the context of several other limitations. First, although the PTOS trauma registry represents a rich repository of data fields, geographical injury locations and prehospital transport times are not reliably recorded. This is particularly significant as the concept of police transport hinges on rapid identification and evacuation of patients with penetrating trauma to designated trauma centers. Furthermore, the PTOS registry does not include prehospital interventions that could either improve survival (eg, tourniquet application) or that conversely might delay transport without enhancing survival (eg, intubation). Future prospective work in this area should note both transport times and interventions.32

    Although the PTOS database does include ISS for each injured body region, it does not contain specific information on the anatomical injuries. This precludes detailed analysis of the association between specific bodily injuries and patient survival. Furthermore, ISS may be inaccurate for patients who die prior to complete imaging or surgical intervention, and because ISS is calculated based on the highest recorded injury severity in 3 different body regions, the ISS for a patient who sustains multiple wounds to a single body region may not reflect the full extent of their injuries. Nonetheless, the incidence of these potential sources of bias should affect both cohorts equally in the present study.

    Although this study sought to match comparable patients, it is possible that using additional characteristics such as presence of a prehospital heart rate, preexisting medical conditions, or injury scene distance from a trauma center would result in more perfect matching between transport groups with improved control of confounding variables. Finally, this analysis focused exclusively on patients with penetrating injuries in an urban environment replete with police, EMS crews, and trauma centers. Thus, these findings may not be generalizable to other types of injuries or to other geographical locations such as suburban or rural areas.7

    Conclusions

    Police transport of patients with penetrating trauma in Philadelphia increased significantly from 2014 to 2018. Patients transported by police were more severely injured and more often hypotensive than patients transported by EMS, yet after controlling for significant differences between groups, patients transported by police had similar mortality. Thus, widespread application of the police transport policy in Philadelphia appears to provide a safe and effective transport modality that can be considered complementary to EMS transport. Patients in other urban locales may benefit from the implementation and broader application of similar policies that encourage police to rapidly transport patients to designated trauma centers without waiting for EMS crews to arrive. Future studies should assess for differences in transport time and the association of prehospital interventions with time to definitive hemostasis and patient survival.

    Back to top
    Article Information

    Accepted for Publication: December 4, 2020.

    Published: January 25, 2021. doi:10.1001/jamanetworkopen.2020.34868

    Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Winter E et al. JAMA Network Open.

    Corresponding Author: Jeremy W. Cannon, MD, Division of Traumatology, Surgical Critical Care and Emergency Surgery, Perelman School of Medicine, University of Pennsylvania, 51 N 39th St, MOB Ste 120, Philadelphia, PA 19104 (jeremy.cannon@pennmedicine.upenn.edu).

    Author Contributions: Mr Winter and Dr Cannon had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

    Concept and design: Winter, Hynes, Malhotra, Cannon.

    Acquisition, analysis, or interpretation of data: All authors.

    Drafting of the manuscript: Winter, Hynes, Shultz, Malhotra, Cannon.

    Critical revision of the manuscript for important intellectual content: Winter, Hynes, Holena, Malhotra, Cannon.

    Statistical analysis: Winter, Shultz, Malhotra, Cannon.

    Administrative, technical, or material support: Winter, Hynes, Holena, Malhotra, Cannon.

    Supervision: Winter, Hynes, Holena, Malhotra, Cannon.

    Conflict of Interest Disclosures: Dr Cannon reported receiving author royalties from UpToDate outside the submitted work. No other disclosures were reported.

    Additional Contributions: Jane Keating, MD, University of Pennsylvania, assisted with the initial design of this study; she was not compensated for her contribution. We also gratefully acknowledge support from the Neurosurgery Quality Improvement Initiative EpiLog Project.

    References
    1.
    Centers for Disease Control and Prevention. WISQARS fatal injury reports, national, regional, and state, 1981-2018. Accessed June 28, 2020. https://webappa.cdc.gov/sasweb/ncipc/mortrate.html
    2.
    Sakran  JV, Mehta  A, Fransman  R,  et al.  Nationwide trends in mortality following penetrating trauma: are we up for the challenge?   J Trauma Acute Care Surg. 2018;85(1):160-166. doi:10.1097/TA.0000000000001907 PubMedGoogle ScholarCrossref
    3.
    Gramlich M. What the data says about gun deaths in the U.S. Pew Research Center. Accessed August 30, 2019. https://www.pewresearch.org/fact-tank/2019/08/16/what-the-data-says-about-gun-deaths-in-the-u-s/
    4.
    Alarhayem  AQ, Myers  JG, Dent  D,  et al.  Time is the enemy: mortality in trauma patients with hemorrhage from torso injury occurs long before the “golden hour”.   Am J Surg. 2016;212(6):1101-1105. doi:10.1016/j.amjsurg.2016.08.018 PubMedGoogle ScholarCrossref
    5.
    Harmsen  AMK, Giannakopoulos  GF, Moerbeek  PR, Jansma  EP, Bonjer  HJ, Bloemers  FW.  The influence of prehospital time on trauma patients outcome: a systematic review.   Injury. 2015;46(4):602-609. doi:10.1016/j.injury.2015.01.008 PubMedGoogle ScholarCrossref
    6.
    Rappold  JF, Hollenbach  KA, Santora  TA,  et al.  The evil of good is better: making the case for basic life support transport for penetrating trauma victims in an urban environment.   J Trauma Acute Care Surg. 2015;79(3):343-348. doi:10.1097/TA.0000000000000783 PubMedGoogle ScholarCrossref
    7.
    Jacoby  SF, Reeping  PM, Branas  CC.  Police-to-hospital transport for violently injured individuals: a way to save lives?   Ann AAPSS. 2020;687(1):186-201. doi:10.1177/0002716219891698 Google ScholarCrossref
    8.
    Branas  CC, Sing  RF, Davidson  SJ.  Urban trauma transport of assaulted patients using nonmedical personnel.   Acad Emerg Med. 1995;2(6):486-493. doi:10.1111/j.1553-2712.1995.tb03245.x PubMedGoogle ScholarCrossref
    9.
    Band  RA, Salhi  RA, Holena  DN, Powell  E, Branas  CC, Carr  BG.  Severity-adjusted mortality in trauma patients transported by police.   Ann Emerg Med. 2014;63(5):608-614.e3. doi:10.1016/j.annemergmed.2013.11.008 PubMedGoogle ScholarCrossref
    10.
    Wandling  MW, Nathens  AB, Shapiro  MB, Haut  ER.  Police transport versus ground EMS: a trauma system–level evaluation of prehospital care policies and their effect on clinical outcomes.   J Trauma Acute Care Surg. 2016;81(5):931-935. doi:10.1097/TA.0000000000001228 PubMedGoogle ScholarCrossref
    11.
    Philadelphia Police Department. Directive 3.14. Published online July 20, 2018. Accessed May 3, 2020. https://www.phillypolice.com/assets/directives/D3.14-HospitalCases.pdf
    12.
    van Brocklin  E. “Scoop and run” can save lives: why don’t more police departments try it? The Trace. Published November 19, 2018. Accessed May 23, 2020. https://www.thetrace.org/2018/11/scoop-and-run-gunshot-victim-police-transport/
    13.
    Detroit Police Department. Transport policy. Accessed May 23, 2020. https://drive.google.com/file/d/1uZdfxwSFuCmQ8xPwf-9zNq9s7tGdA1v_/view?usp=embed_facebook
    14.
    Pennsylvania Trauma Systems Foundation. About. Accessed May 3, 2020. http://ptsf.org/registry/about
    15.
    Baker  SP, O’Neill  B.  The Injury Severity Score: an update.   J Trauma. 1976;16(11):882-885. doi:10.1097/00005373-197611000-00006 PubMedGoogle ScholarCrossref
    16.
    Pal  J, Brown  R, Fleiszer  D.  The value of the Glasgow Coma Scale and Injury Severity Score: predicting outcome in multiple trauma patients with head injury.   J Trauma. 1989;29(6):746-748. doi:10.1097/00005373-198906000-00008 PubMedGoogle ScholarCrossref
    17.
    Gill  M, Windemuth  R, Steele  R, Green  SM.  A comparison of the Glasgow Coma Scale score to simplified alternative scores for the prediction of traumatic brain injury outcomes.   Ann Emerg Med. 2005;45(1):37-42. doi:10.1016/j.annemergmed.2004.07.429 PubMedGoogle ScholarCrossref
    18.
    Champion  HR, Sacco  WJ, Copes  WS, Gann  DS, Gennarelli  TA, Flanagan  ME.  A revision of the Trauma Score.   J Trauma. 1989;29(5):623-629. doi:10.1097/00005373-198905000-00017 PubMedGoogle ScholarCrossref
    19.
    Fay  MP, Hunsberger  SA, Nason  M, Gabriel  E, Lumbard  K. exact2x2: Exact tests and confidence intervals for 2x2 tables. Accessed June 15, 2020. https://cran.r-project.org/web/packages/exact2x2/index.html
    20.
    Sjölander  A, Greenland  S.  Ignoring the matching variables in cohort studies—when is it valid and why?   Stat Med. 2013;32(27):4696-4708. doi:10.1002/sim.5879 PubMedGoogle ScholarCrossref
    21.
    SAS Institute Inc. Analytics software & solutions. Accessed June 28, 2020. https://www.sas.com/en_us/home.html
    22.
    The R Project for Statistical Computing. Getting started. Accessed June 28, 2020. https://www.r-project.org/
    23.
    Ho  D, Imai  K, King  G, Stuart  EA.  MatchIt: nonparametric preprocessing for parametric causal inference.   J Stat Softw. 2011;42(1):1-28. doi:10.18637/jss.v042.i08 PubMedGoogle Scholar
    24.
    Fay  MP, Hunsberger  SA, Nason  M, Gabriel  E, Lumbard  K. exact2x2: Exact tests and confidence intervals for 2x2 tables. 2019. Accessed June 15, 2020. https://CRAN.R-project.org/package=exact2x2
    25.
    Crandall  M, Sharp  D, Unger  E,  et al.  Trauma deserts: distance from a trauma center, transport times, and mortality from gunshot wounds in Chicago.   Am J Public Health. 2013;103(6):1103-1109. doi:10.2105/AJPH.2013.301223 PubMedGoogle ScholarCrossref
    26.
    Tung  EL, Hampton  DA, Kolak  M, Rogers  SO, Yang  JP, Peek  ME.  Race/ethnicity and geographic access to urban trauma care.   JAMA Netw Open. 2019;2(3):e190138. doi:10.1001/jamanetworkopen.2019.0138 PubMedGoogle Scholar
    27.
    Johnson  KE.  Police–Black community relations in postwar Philadelphia: race and criminalization in urban social spaces, 1945-1960.   J Afr Am Hist. 2004;89(2):118-134. doi:10.2307/4134096 Google Scholar
    28.
    Brunson  RK, Miller  J.  Young Black men and urban policing in the United States.   Br J Criminol. 2006;46(4):613-640. doi:10.1093/bjc/azi093 Google ScholarCrossref
    29.
    Jacoby  SF, Richmond  TS, Holena  DN, Kaufman  EJ.  A safe haven for the injured? urban trauma care at the intersection of healthcare, law enforcement, and race.   Soc Sci Med. 2018;199:115-122. doi:10.1016/j.socscimed.2017.05.037 PubMedGoogle ScholarCrossref
    30.
    Busch  J.  Shots fired: when a police car becomes an ambulance: in Philadelphia cops can transport penetrating-trauma patients; will other systems follow suit?   EMS World. 2013;42(5):I8.PubMedGoogle Scholar
    31.
    Iacus  SM, King  G, Porro  G.  Causal inference without balance checking: coarsened exact matching.   Political Analysis. 2012;20(01):1-24. doi:10.1093/pan/mpr013 Google ScholarCrossref
    32.
    Holcomb  JB.  Transport time and preoperating room hemostatic interventions are important: improving outcomes after severe truncal injury.   Crit Care Med. 2018;46(3):447-453. doi:10.1097/CCM.0000000000002915 PubMedGoogle ScholarCrossref
    ×