Quantitative assessments of how trainees affect patient care have been limited, especially in the emergency department (ED). A US study by Pitts et al found that supervised resident visits were associated with greater resource use, including longer length of stay (LOS) in the ED. As EDs host more core clerkship courses, less experienced students have become involved in bedside care. This study examined the association between the presence of medical students in the ED and patient LOS, an established patient-centered outcome and marker of ED performance

Abella, Benjamin

Hennessey, Sean

Ionnides, Kimon

Mamtani, Mira

Scott, Kevin

Shofer, Frances S

Small, Dylan S

English

Kosmopolis

University of Pennsylvania
ScholarlyCommons
Statistics Papers Wharton Faculty Research
12-8-2015
Medical Students in the Emergency Department
and Patient Length of Stay
Kimon Ionnides
University of Pennsylvania
Mira Mamtani
University of Pennsylvania
Frances S. Shofer
University of Pennsylvania
Dylan S. Small
University of Pennsylvania
Sean Hennessey
University of Pennsylvania
See next page for additional authors
Follow this and additional works at: http://repository.upenn.edu/statistics_papers
Part of the Life Sciences Commons, Medicine and Health Sciences Commons, Physical Sciences
and Mathematics Commons, and the Social and Behavioral Sciences Commons
This paper is posted at ScholarlyCommons. http://repository.upenn.edu/statistics_papers/66
For more information, please contact repository@pobox.upenn.edu.
Recommended Citation
Ionnides, K., Mamtani, M., Shofer, F. S., Small, D. S., Hennessey, S., Abella, B., & Scott, K. (2015). Medical Students in the Emergency
Department and Patient Length of Stay. Journal of the American Medical Association, 314 (22), 2411-2413. http://dx.doi.org/10.1001/
jama.2015.16476
Medical Students in the Emergency Department and Patient Length of
Stay
Abstract
Quantitative assessments of how trainees affect patient care have been limited, especially in the emergency
department (ED). A US study by Pitts et al found that supervised resident visits were associated with greater
resource use, including longer length of stay (LOS) in the ED. As EDs host more core clerkship courses, less
experienced students have become involved in bedside care. This study examined the association between the
presence of medical students in the ED and patient LOS, an established patient-centered outcome and marker
of ED performance.
Disciplines
Life Sciences | Medicine and Health Sciences | Physical Sciences and Mathematics | Social and Behavioral
Sciences
Author(s)
Kimon Ionnides, Mira Mamtani, Frances S. Shofer, Dylan S. Small, Sean Hennessey, Benjamin Abella, and
Kevin Scott
This journal article is available at ScholarlyCommons: http://repository.upenn.edu/statistics_papers/66
Copyright 2015 American Medical Association. All rights reserved.
Medical Students in the Emergency Department
and Patient Length of Stay
Quantitative assessments of how trainees affect patient care
have been limited, especially in the emergency department
(ED). A US study by Pitts et al1 found that supervised resident
visits were associated with greater resource use, including lon-
ger length of stay (LOS) in the ED. As EDs host more core clerk-
ship courses, less experienced students have become in-
volved in bedside care.2 This study examined the association
between the presence of medical students in the ED and pa-
tient LOS, an established patient-centered outcome and marker
of ED performance.3
Methods | During a required third-year emergency medicine
clerkship at 3 urban, academic EDs associated with the Uni-
versity of Pennsylvania Health System, Philadelphia, stu-
dents were assigned approximately nine 8- to 12-hour shifts
over 3 weeks, during which they were expected to evaluate
and follow-up several patients presenting to the ED. The
institutional review board at the University of Pennsylvania
approved this study and provided a waiver of participant
consent.
During the fourth week of each rotation, students partici-
pated in an anesthesiology week and were absent from the ED.
We examined sequential patient visits from 2000 through
2014, calculating LOS from arrival until ED discharge or ad-
mission, and comparing clerkship student presence with stu-
dent absence from the ED. Summer and winter vacation pe-
riods were excluded.
Multivariable generalized linear models included visit-
level covariates and dummy variables for all clerkship
weeks, and for weeks 1, 2, and 3 individually, and used a
γ distribution and clustering by day and hospital. Baseline
differences in covariates were assessed for potential con-
founding factors along with the prevalence of International
Classification of Diseases, Ninth Revision (ICD-9), diagnosis
codes (using the Benjamini-Hochberg correction for mul-
tiple comparisons).
Sensitivity analyses were performed by assessing unad-
justed differences using t tests, examining each year and hos-
pital individually, and reassigning visits in which patients left
without being seen to varying percentiles of LOS. Two-sided
statistical tests with an α level of .05 were performed using
Stata version 13 (StataCorp).
Results | More than 1.3 million ED visits were analyzed (Table 1).
There were no significant differences among visit covariates,
including ICD-9 code prevalence, between clerkship and con-
trol weeks. Weekly resident turnover rate was significantly
lower during the clerkship weeks compared with the control
weeks (mean [SD], 17.8% [16.1%] vs 19.8% [17.5%], respec-
tively), but was not correlated with LOS.
Mean (SD) LOS was 264.7 (253.7) minutes overall; ad-
justed LOS was 4.6 minutes (95% CI, 2.7-6.6 minutes) longer
(P < .001) when clerkship students were present in the ED
(Table 2). This was significant across all 3 hospitals and con-
sistent across each of the 3 clerkship weeks. Unadjusted dif-
ferences for the primary outcome and the sensitivity analysis
Table 1. Baseline Demographic and Emergency Department Visit
Characteristicsa
Clerkship
(n =1 029 165
Visits)
Control
(n = 343 696
Visits)
Standardized
Mean
Differenceb
No. of weeks 540 180
Age group, y
<18 15 598 (1.5) 5377 (1.6) 0.004
18-39 468 897 (45.6) 157 012 (45.7) 0.002
40-64 377 854 (36.7) 125 609 (36.5) 0.003
65-90 153 328 (14.9) 51 052 (14.9) 0.001
>90 12 953 (1.3) 4476 (1.3) 0.004
Unknown 535 (0.1) 170 (0.05) 0.001
Male sex 430 106 (41.8) 142 800 (41.5) 0.005
Race/ethnicityc
Black 673 112 (65.4) 224 853 (65.4) <0.001
White 247 956 (24.1) 82 473 (24.0) 0.002
Hispanic 21 999 (2.1) 7390 (2.2) 0.001
Asian 16 470 (1.6) 5631 (1.6) 0.003
Unknown 69 628 (6.8) 23 349 (6.8) 0.001
Emergency Severity Index
1 (most acute) 24 531 (2.4) 7891 (2.3) 0.006
2 220 789 (21.5) 73 382 (21.4) 0.002
3 470 087 (45.7) 157 835 (45.9) 0.005
4 263 399 (25.6) 87 943 (25.6) <0.001
5 (least acute) 28 018 (2.7) 9337 (2.7) <0.001
Unassigned 22 341 (2.2) 7308 (2.1) 0.003
Arrival date and time
Midnight-7 AM 165 983 (16.1) 54 008 (15.7) 0.011
Weekend 264 939 (25.7) 88 172 (25.7) 0.002
First month
of electronic
medical record
implementation
2424 (0.2) 811 (0.2) <0.001
Dispositiond
Admitted 234 227 (22.8) 77 971 (22.7) 0.002
Transferred 22 999 (2.2) 7409 (2.2) 0.005
Discharged 711 333 (69.1) 238 831 (69.5) 0.008
Left against
medical advice
16 261 (1.6) 5316 (1.5) 0.003
Left without
being seen
43 049 (4.2) 13 757 (4.0) 0.009
Died 1296 (0.1) 412 (0.1) 0.002
Emergency department conditions at arrival, mean (SD)
No. boardingd,e 1.90 (2.97) 1.92 (2.98) 0.006
Hourly arrivals 7.77 (4.74) 7.69 (3.90) 0.018
Daily volume 136.13 (40.35) 135.87 (39.74) 0.006
% Weekly
resident
turnover
17.8 (16.1) 19.8 (17.5) 0.122
a Data are expressed as No. (%) unless otherwise indicated. Covariates included
in the regression were determined during patient triage prior to medical
student contact.
b Calculated as difference in means divided by overall SD (used due to the large
sample size). Values larger than 0.10 (>10% of an SD) are potentially important.
c Recorded at patient triage or from prior patient record, usually selected from
predesignated list (varied by hospital site and year). Included to assess for
differences in patient population and comorbidities.
d Not included as covariates in regression because they are determined after
medical student contact with patients.
e Patient admitted to hospital but awaiting transfer to an inpatient unit.
Letters
jama.com (Reprinted) JAMA December 8, 2015 Volume 314, Number 22 2411
Downloaded From: http://jamanetwork.com/ on 08/22/2017
Copyright 2015 American Medical Association. All rights reserved.
Ta
bl
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ed
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n
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Q
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9
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3
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Ab
br
ev
ia
tio
n:
IQ
R,
in
te
rq
ua
rt
ile
ra
ng
e.
a
U
nl
es
so
th
er
w
ise
in
di
ca
te
d,
da
ta
ar
e
ad
ju
st
ed
re
gr
es
sio
n
es
tim
at
es
of
in
cr
ea
se
in
LO
S
fo
rc
le
rk
sh
ip
w
ee
ks
re
la
tiv
e
to
co
nt
ro
lw
ee
ks
us
in
g
av
er
ag
e
ad
ju
st
ed
pr
ed
ic
te
d
m
ar
gi
na
le
ffe
ct
s.
b
W
ee
k
1v
sw
ee
k
2
yi
el
de
d
P
va
lu
es
of
.3
3
fo
ra
llh
os
pi
ta
ls;
.8
5
fo
rh
os
pi
ta
lA
;.
77
fo
rh
os
pi
ta
lB
;a
nd
.0
2
fo
rh
os
pi
ta
l
C.
W
ee
k
2
vs
w
ee
k
3
yi
el
de
d
P
va
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of
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fo
ra
llh
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ta
ls;
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6
fo
rh
os
pi
ta
lA
;.
70
fo
rh
os
pi
ta
lB
;a
nd
.17
fo
r
ho
sp
ita
lC
.W
ee
k
1v
sw
ee
k
3
yi
el
de
d
P
va
lu
es
of
.7
4
fo
ra
llh
os
pi
ta
ls;
.2
6
fo
rh
os
pi
ta
lA
;.
47
fo
rh
os
pi
ta
lB
;
an
d
.3
2
fo
rh
os
pi
ta
lC
.
c
Al
ld
at
a
in
th
is
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Letters
2412 JAMA December 8, 2015 Volume 314, Number 22 (Reprinted) jama.com
Downloaded From: http://jamanetwork.com/ on 08/22/2017
Copyright 2015 American Medical Association. All rights reserved.
of left without being seen visits were similar. Subanalysis of
each year at each site showed that LOS was either longer when
students were present or not significantly different from the
control weeks.
Discussion | Our findings show an increase in LOS of approxi-
mately 5 minutes associated with the presence of medical
students in the ED, which was statistically significant but
likely too small to be of clinical relevance (equivalent to 2%
of 1 SD in LOS). This conclusion was robust for all sensitivity
analyses and persisted across 3 different hospitals with dis-
tinct teaching models, patient populations, and workflow.
Prior studies have had conflicting results and only demon-
strated longer LOS for the select patients examined by stu-
dents directly.4-6
An important limitation is the absence of visit-level infor-
mation on student involvement with patients. Without this,
we were able to examine only the association of the clerkship
with aggregate overall LOS. In addition, indirect effects, such
as attending physicians spending extra time documenting
after shifts as a consequence of teaching students during
clinical time, were not assessed, and this study took place at
3 hospitals associated with a single medical school. Future
studies should assess different student experiences and other
patient-centered or financial outcomes.
Kimon L.H. Ioannides, BS
Mira Mamtani, MD
Frances S. Shofer, PhD
Dylan S. Small, PhD
Sean Hennessy, PharmD, PhD
Benjamin S. Abella, MD, MPhil
Kevin R. Scott, MD
Author Affiliations: Perelman School of Medicine, University of Pennsylvania,
Philadelphia (Ioannides); Department of Emergency Medicine, University of
Pennsylvania, Philadelphia (Mamtani, Shofer, Abella, Scott); Department of
Statistics, University of Pennsylvania Wharton School, Philadelphia (Small);
Department of Biostatistics and Epidemiology, University of Pennsylvania,
Philadelphia (Hennessy).
Corresponding Author: Kevin R. Scott, MD, Department of Emergency
Medicine, 3400 Spruce St, Ground Ravdin, Philadelphia, PA 19104
(kevin.scott@uphs.upenn.edu).
Author Contributions: Mr Ioannides had full access to all the data in the study
and takes responsibility for the integrity of the data and the accuracy of the data
analysis.
Study concept and design: Ioannides, Hennessy, Scott.
Acquisition, analysis, or interpretation of data: Ioannides, Shofer, Small,
Hennessy, Abella, Scott.
Drafting of the manuscript: Ioannides, Mamtani, Scott.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Ioannides, Shofer, Small.
Administrative, technical, or material support: Small, Abella, Scott.
Study supervision: Mamtani, Abella, Scott.
Conflict of Interest Disclosures: The authors have completed and submitted
the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Abella
reported receiving grants from the National Heart, Lung, and Blood Institute,
Philips Healthcare, Medtronic Foundation, and Stryker Medical; and receiving
other (honoraria, stock ownership, serving on advisory boards, or serving as a
consultant) from Velomedix Corp, HeartSine Corp, Ikaria Inc, Resuscor, Bard,
and Stryker Medical. No other disclosures were reported.
Funding/Support: The Department of Emergency Medicine, University of
Pennsylvania, provided funding for this study.
Role of the Funder/Sponsor: The Department of Emergency Medicine,
University of Pennsylvania, had no role in the design and conduct of the study;
had a role in the collection, management, analysis, and interpretation of the
data; had no role in the preparation, review, or approval of the manuscript; and
had no role in the decision to submit the manuscript for publication.
Previous Presentations: A preliminary version of these data were presented in
part at a pharmacoepidemiology rounds on April 17, 2015, at the University of
Pennsylvania and at an internal research-in-progress meeting on April 29, 2015.
Additional Contributions: We thank the following individuals at the
University of Pennsylvania for their contributions without compensation:
Carmen Farrow, MS, MBA, for special data analysis and technical assistance
with EMR databases; Ari B. Friedman, PhD, for analysis and operational
feedback; Jennifer R. Kogan, MD, for advising and providing feedback; and
Elizabeth D. Lowenthal, MD, MSCE, and Iris M. Reyes, MD, for advising
and providing assistance with the protocol.
1. Pitts SR, Morgan SR, Schrager JD, Berger TJ. Emergency department
resource use by supervised residents vs attending physicians alone. JAMA.
2014;312(22):2394-2400.
2. Goldfarb S, Morrison G. The 3-year medical school—change or shortchange?
N Engl J Med. 2013;369(12):1087-1089.
3. Pines JM, Decker SL, Hu T. Exogenous predictors of national performance
measures for emergency department crowding. Ann Emerg Med. 2012;60(3):
293-298.
4. DeLaney M, Zimmerman KD, Strout TD, Fix ML. The effect of medical
students and residents on measures of efficiency and timeliness in an academic
medical center emergency department. Acad Med. 2013;88(11):1723-1731.
5. Hiller K, Viscusi C, Beskind D, Bradshaw H, Berkman M, Greene S. Cost of an
acting intern: clinical productivity in the academic emergency department.
J Emerg Med. 2014;47(2):216-222.
6. Dehon E, McLemore G, McKenzie LK. Impact of trainees on length of stay in
the emergency department at an academic medical center. South Med J. 2015;
108(5):245-248.
COMMENT & RESPONSE
Initial Interventions for Out-of-Hospital
Cardiac Arrest
To the Editor Early initiation of basic life support has been
proven to decrease mortality, which was reaffirmed by
Dr Malta Hansen and colleagues.1 Since the early 2000s,
patients have benefited from induced hypothermia after
return of spontaneous circulation after cardiac arrest. A 2002
study demonstrated that 49% of patients who were treated
with hypothermia after out-of-hospital cardiac arrest sur-
vived with good neurological outcomes as opposed to only
26% treated with normothermia.2
The study by Malta Hansen and colleagues,1 which looked
at patient survival and neurological outcomes 8 years after out-
of-hospital cardiac arrest, did not differentiate outcomes in pa-
tients who received hypothermia vs normothermia. We won-
der whether the authors have data regarding therapeutic
hypothermia and if it confounded the results of the trial.
Furthermore, the definition of a bystander who per-
formed cardiopulmonary resuscitation (CPR), defibrillation,
or both was not discussed. There was also no explanation of
how cardiac arrest was confirmed. In a study on rapid defi-
brillation in casinos,3 patients were assessed for responsive-
ness, spontaneous respirations, and palpable carotid pulse;
the nearest defibrillator was then used to assess their cardiac
rhythm.
Malta Hansen and colleagues did not discuss how it was
determined whether a patient had a pulse. It also is unclear
Letters
jama.com (Reprinted) JAMA December 8, 2015 Volume 314, Number 22 2413
Downloaded From: http://jamanetwork.com/ on 08/22/2017


Medical Students in the Emergency Department and Patient Length of Stay

ScholarlyCommons@Penn

University of PennsylvaniaScholarlyCommonsStatistics Papers Wharton Faculty Research12-8-2015Medical Students in the Emergency Departmentand Patient Length of StayKimon IonnidesUniversity of PennsylvaniaMira MamtaniUniversity of PennsylvaniaFrances S. ShoferUniversity of PennsylvaniaDylan S. SmallUniversity of PennsylvaniaSean HennesseyUniversity of PennsylvaniaSee next page for additional authorsFollow this and additional works at: http://repository.upenn.edu/statistics_papersPart of the Life Sciences Commons, Medicine and Health Sciences Commons, Physical Sciencesand Mathematics Commons, and the Social and Behavioral Sciences CommonsThis paper is posted at ScholarlyCommons. http://repository.upenn.edu/statistics_papers/66For more information, please contact repository@pobox.upenn.edu.Recommended CitationIonnides, K., Mamtani, M., Shofer, F. S., Small, D. S., Hennessey, S., Abella, B., & Scott, K. (2015). Medical Students in the EmergencyDepartment and Patient Length of Stay. Journal of the American Medical Association, 314 (22), 2411-2413. http://dx.doi.org/10.1001/jama.2015.16476Medical Students in the Emergency Department and Patient Length ofStayAbstractQuantitative assessments of how trainees affect patient care have been limited, especially in the emergencydepartment (ED). A US study by Pitts et al found that supervised resident visits were associated with greaterresource use, including longer length of stay (LOS) in the ED. As EDs host more core clerkship courses, lessexperienced students have become involved in bedside care. This study examined the association between thepresence of medical students in the ED and patient LOS, an established patient-centered outcome and markerof ED performance.DisciplinesLife Sciences | Medicine and Health Sciences | Physical Sciences and Mathematics | Social and BehavioralSciencesAuthor(s)Kimon Ionnides, Mira Mamtani, Frances S. Shofer, Dylan S. Small, Sean Hennessey, Benjamin Abella, andKevin ScottThis journal article is available at ScholarlyCommons: http://repository.upenn.edu/statistics_papers/66Copyright 2015 American Medical Association. All rights reserved.Medical Students in the EmergencyDepartmentand Patient Length of StayQuantitative assessments of how trainees affect patient carehave been limited, especially in the emergency department(ED). A US study by Pitts et al1 found that supervised residentvisitswereassociatedwithgreater resourceuse, including lon-ger lengthof stay (LOS) in theED.AsEDshostmore core clerk-ship courses, less experienced students have become in-volved in bedside care.2 This study examined the associationbetween the presence of medical students in the ED and pa-tientLOS,anestablishedpatient-centeredoutcomeandmarkerof ED performance.3Methods | During a required third-year emergency medicineclerkship at 3 urban, academic EDs associated with the Uni-versity of Pennsylvania Health System, Philadelphia, stu-dents were assigned approximately nine 8- to 12-hour shiftsover 3 weeks, during which they were expected to evaluateand follow-up several patients presenting to the ED. Theinstitutional review board at the University of Pennsylvaniaapproved this study and provided a waiver of participantconsent.During the fourthweek of each rotation, students partici-pated inananesthesiologyweekandwereabsent fromtheED.We examined sequential patient visits from 2000 through2014, calculating LOS from arrival until ED discharge or ad-mission, and comparing clerkship student presencewith stu-dent absence from the ED. Summer and winter vacation pe-riods were excluded.Multivariable generalized linear models included visit-level covariates and dummy variables for all clerkshipweeks, and for weeks 1, 2, and 3 individually, and used aγ distribution and clustering by day and hospital. Baselinedifferences in covariates were assessed for potential con-founding factors along with the prevalence of InternationalClassification of Diseases, Ninth Revision (ICD-9), diagnosiscodes (using the Benjamini-Hochberg correction for mul-tiple comparisons).Sensitivity analyses were performed by assessing unad-justed differences using t tests, examining each year and hos-pital individually, and reassigning visits in which patients leftwithout being seen to varying percentiles of LOS. Two-sidedstatistical tests with an α level of .05 were performed usingStata version 13 (StataCorp).Results |More than 1.3millionEDvisitswereanalyzed (Table 1).There were no significant differences among visit covariates,including ICD-9 codeprevalence, between clerkship and con-trol weeks. Weekly resident turnover rate was significantlylower during the clerkship weeks compared with the controlweeks (mean [SD], 17.8% [16.1%] vs 19.8% [17.5%], respec-tively), but was not correlated with LOS.Mean (SD) LOS was 264.7 (253.7) minutes overall; ad-justed LOS was 4.6 minutes (95% CI, 2.7-6.6 minutes) longer(P < .001) when clerkship students were present in the ED(Table 2). This was significant across all 3 hospitals and con-sistent across each of the 3 clerkship weeks. Unadjusted dif-ferences for the primary outcome and the sensitivity analysisTable 1. Baseline Demographic and Emergency Department VisitCharacteristicsaClerkship(n =1 029 165Visits)Control(n = 343 696Visits)StandardizedMeanDifferencebNo. of weeks 540 180Age group, y<18 15598 (1.5) 5377 (1.6) 0.00418-39 468897 (45.6) 157012 (45.7) 0.00240-64 377854 (36.7) 125609 (36.5) 0.00365-90 153328 (14.9) 51052 (14.9) 0.001>90 12953 (1.3) 4476 (1.3) 0.004Unknown 535 (0.1) 170 (0.05) 0.001Male sex 430106 (41.8) 142800 (41.5) 0.005Race/ethnicitycBlack 673112 (65.4) 224853 (65.4) <0.001White 247956 (24.1) 82473 (24.0) 0.002Hispanic 21 999 (2.1) 7390 (2.2) 0.001Asian 16470 (1.6) 5631 (1.6) 0.003Unknown 69628 (6.8) 23 349 (6.8) 0.001Emergency Severity Index1 (most acute) 24 531 (2.4) 7891 (2.3) 0.0062 220789 (21.5) 73382 (21.4) 0.0023 470087 (45.7) 157835 (45.9) 0.0054 263399 (25.6) 87943 (25.6) <0.0015 (least acute) 28 018 (2.7) 9337 (2.7) <0.001Unassigned 22341 (2.2) 7308 (2.1) 0.003Arrival date and timeMidnight-7 AM 165983 (16.1) 54008 (15.7) 0.011Weekend 264939 (25.7) 88172 (25.7) 0.002First monthof electronicmedical recordimplementation2424 (0.2) 811 (0.2) <0.001DispositiondAdmitted 234227 (22.8) 77971 (22.7) 0.002Transferred 22999 (2.2) 7409 (2.2) 0.005Discharged 711333 (69.1) 238831 (69.5) 0.008Left againstmedical advice16261 (1.6) 5316 (1.5) 0.003Left withoutbeing seen43049 (4.2) 13 757 (4.0) 0.009Died 1296 (0.1) 412 (0.1) 0.002Emergency department conditions at arrival, mean (SD)No. boardingd,e 1.90 (2.97) 1.92 (2.98) 0.006Hourly arrivals 7.77 (4.74) 7.69 (3.90) 0.018Daily volume 136.13 (40.35) 135.87 (39.74) 0.006%Weeklyresidentturnover17.8 (16.1) 19.8 (17.5) 0.122a Data are expressed as No. (%) unless otherwise indicated. Covariates includedin the regression were determined during patient triage prior to medicalstudent contact.b Calculated as difference inmeans divided by overall SD (used due to the largesample size). Values larger than0.10 (>10%of an SD) are potentially important.c Recorded at patient triage or from prior patient record, usually selected frompredesignated list (varied by hospital site and year). Included to assess fordifferences in patient population and comorbidities.dNot included as covariates in regression because they are determined aftermedical student contact with patients.e Patient admitted to hospital but awaiting transfer to an inpatient unit.Lettersjama.com (Reprinted) JAMA December 8, 2015 Volume 314, Number 22 2411Downloaded From: http://jamanetwork.com/ on 08/22/2017Copyright 2015 American Medical Association. All rights reserved.Table2.LengthofStay(LOS)forClerkshipWeeksComparedWithControlWeeksAllHospitalsHospitalAHospitalBHospitalCVisits,No.(%)1372861(100)799883(58.3)184154(13.4)388824(28.3)No.ofyearsincluded15(yearrange,2000to2014)15(yearrange,2000to2014)6(yearrange,2009to2014)12(yearrange,2003to2014)No.ofaverageyearlyvisits91524533263069232402TypicalNo.ofstudents/mo14824PersontowhomstudentsreportResidentAttendingAttendingAdjustedDifferencesinLOS(95%CI),minaP ValueAdjustedDifferencesinLOS(95%CI),minaP ValueAdjustedDifferencesinLOS(95%CI),minaP ValueAdjustedDifferencesinLOS(95%CI),minaP ValueAllclerkshipvscontrol4.6(2.7to6.6)<.0014.1(1.6to6.6).0016.5(1.7to11.4).0085.2(1.6to8.8).005Week1bvscontrol4.1(1.7to6.5).0014.7(1.6to7.7).0035.1(−0.9to11.1).102.0(−2.5to6.6).38Week2bvscontrol5.3(2.9to7.7)<.0014.4(1.3to7.5).0066.0(−0.3to12.4).067.6(3.1to12.0).001Week3bvscontrol3.7(1.3to6.1).0022.9(−0.1to6.0).067.3(1.5to13.0).014.4(−0.1to9.0).06Year 200019.1(7.6to30.7).00119.1(7.6to30.7).00120014.2(−5.2to13.6).384.2(−5.2to13.6).38200210.4(1.5to19.3).0210.4(1.5to19.3).0220033.9(−3.6to11.4).304.2(−3.8to12.1).313.4(−13.9to20.7).7020049.2(0to18.5).056.7(−4.0to17.4).2215.3(−2.9to33.6).10200511.0(4.0to18.1).0027.7(−0.2to15.7).0618.5(3.9to33.0).0120063.0(−5.4to11.4).482.8(−7.6to13.2).603.5(−10.9to17.8).6420073.6(−4.8to11.9).40−1.1(−12.4to10.1).8414.7(−1.4to30.8).0720089.5(1.1to17.8).0316.4(4.1to28.7).009−2.5(−15.6to10.5).7020093.2(−2.3to8.7).263.8(−3.6to11.2).329.0(−7.9to26.0).30−3.0(−11.3to5.3).4920104.0(−0.6to8.7).09−0.4(−7.5to6.6).9010.0(0.1to19.9).058.9(0.6to17.3).0420113.1(−1.4to7.6).172.6(−4.0to9.3).44−0.2(−9.0to8.6).966.4(−1.9to14.7).1320123.9(−0.7to8.6).105.0(−1.5to11.4).136.0(−3.5to15.4).22−1.6(−10.7to7.5).732013−2.0(−6.7to2.7).40−6.2(−13.2to0.8).08−0.4(−7.7to6.9).918.0(0.2to15.9).0520144.5(−0.1to9.1).064.7(−1.9to11.4).165.5(−3.3to14.3).222.8(−5.6to11.2).51Patientsleftwithoutbeingseen5%4.1(2.4to5.9)<.0013.8(1.5to6.1).0015.8(1.4to10.2).014.2(1.1to7.3).0150%4.1(2.4to5.9)<.0014.0(1.6to6.4).0016.5(1.8to11.2).014.9(1.5to8.2).00495%5.4(3.3to7.5)<.0014.6(1.8to7.3).0018.3(2.6to14.0).0046.7(2.6to10.7).001Unadjusted(allclerkship−control)c5.9(4.9to6.9)<.0015.8(4.3to7.3)<.0014.6(3.1to6.1)<.0016.3(4.9to7.6)<.001Unadjusted,mean(SD)Allclerkshipandcontrol264.7(253.7)302.6(293.1)213.8(143.2)211.0(183.7)Median(IQR)205.3(118.0to336.4)235.9(135.4to380.1)185.7(115.8to279.6)166.0(91.8to275.3)Allclerkship,wk266.2(254.7)304.0(294.1)215.0(143.3)212.6(185.1)Control,wk260.3(250.5)298.2(289.8)210.3(142.9)206.3(179.6)Abbreviation:IQR,interquartilerange.aUnlessotherwiseindicated,dataareadjustedregressionestimatesofincreaseinLOSforclerkshipweeksrelativetocontrolweeksusingaverageadjustedpredictedmarginaleffects.bWeek1vsweek2yieldedPvaluesof.33forallhospitals;.85forhospitalA;.77forhospitalB;and.02forhospitalC.Week2vsweek3yieldedPvaluesof.19forallhospitals;.36forhospitalA;.70forhospitalB;and.17forhospitalC.Week1vsweek3yieldedPvaluesof.74forallhospitals;.26forhospitalA;.47forhospitalB;and.32forhospitalC.cAlldatainthisrowwerecalculatedusingthettest.Letters2412 JAMA December 8, 2015 Volume 314, Number 22 (Reprinted) jama.comDownloaded From: http://jamanetwork.com/ on 08/22/2017Copyright 2015 American Medical Association. All rights reserved.of left without being seen visits were similar. Subanalysis ofeachyear at each site showed that LOSwas either longerwhenstudents were present or not significantly different from thecontrol weeks.Discussion | Our findings show an increase in LOS of approxi-mately 5 minutes associated with the presence of medicalstudents in the ED, which was statistically significant butlikely too small to be of clinical relevance (equivalent to 2%of 1 SD in LOS). This conclusion was robust for all sensitivityanalyses and persisted across 3 different hospitals with dis-tinct teaching models, patient populations, and workflow.Prior studies have had conflicting results and only demon-strated longer LOS for the select patients examined by stu-dents directly.4-6An important limitation is the absence of visit-level infor-mation on student involvement with patients. Without this,we were able to examine only the association of the clerkshipwith aggregate overall LOS. In addition, indirect effects, suchas attending physicians spending extra time documentingafter shifts as a consequence of teaching students duringclinical time, were not assessed, and this study took place at3 hospitals associated with a single medical school. Futurestudies should assess different student experiences and otherpatient-centered or financial outcomes.Kimon L.H. Ioannides, BSMira Mamtani, MDFrances S. Shofer, PhDDylan S. Small, PhDSean Hennessy, PharmD, PhDBenjamin S. Abella, MD, MPhilKevin R. Scott, MDAuthor Affiliations: Perelman School of Medicine, University of Pennsylvania,Philadelphia (Ioannides); Department of EmergencyMedicine, University ofPennsylvania, Philadelphia (Mamtani, Shofer, Abella, Scott); Department ofStatistics, University of Pennsylvania Wharton School, Philadelphia (Small);Department of Biostatistics and Epidemiology, University of Pennsylvania,Philadelphia (Hennessy).Corresponding Author: Kevin R. Scott, MD, Department of EmergencyMedicine, 3400 Spruce St, Ground Ravdin, Philadelphia, PA 19104(kevin.scott@uphs.upenn.edu).Author Contributions:Mr Ioannides had full access to all the data in the studyand takes responsibility for the integrity of the data and the accuracy of the dataanalysis.Study concept and design: Ioannides, Hennessy, Scott.Acquisition, analysis, or interpretation of data: Ioannides, Shofer, Small,Hennessy, Abella, Scott.Drafting of the manuscript: Ioannides, Mamtani, Scott.Critical revision of the manuscript for important intellectual content: All authors.Statistical analysis: Ioannides, Shofer, Small.Administrative, technical, or material support: Small, Abella, Scott.Study supervision:Mamtani, Abella, Scott.Conflict of Interest Disclosures: The authors have completed and submittedthe ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Abellareported receiving grants from the National Heart, Lung, and Blood Institute,Philips Healthcare, Medtronic Foundation, and Stryker Medical; and receivingother (honoraria, stock ownership, serving on advisory boards, or serving as aconsultant) from Velomedix Corp, HeartSine Corp, Ikaria Inc, Resuscor, Bard,and Stryker Medical. No other disclosures were reported.Funding/Support: The Department of EmergencyMedicine, University ofPennsylvania, provided funding for this study.Role of the Funder/Sponsor: The Department of EmergencyMedicine,University of Pennsylvania, had no role in the design and conduct of the study;had a role in the collection, management, analysis, and interpretation of thedata; had no role in the preparation, review, or approval of themanuscript; andhad no role in the decision to submit themanuscript for publication.Previous Presentations: A preliminary version of these data were presented inpart at a pharmacoepidemiology rounds on April 17, 2015, at the University ofPennsylvania and at an internal research-in-progress meeting on April 29, 2015.Additional Contributions:We thank the following individuals at theUniversity of Pennsylvania for their contributions without compensation:Carmen Farrow, MS, MBA, for special data analysis and technical assistancewith EMR databases; Ari B. Friedman, PhD, for analysis and operationalfeedback; Jennifer R. Kogan, MD, for advising and providing feedback; andElizabeth D. Lowenthal, MD, MSCE, and Iris M. Reyes, MD, for advisingand providing assistance with the protocol.1. Pitts SR, Morgan SR, Schrager JD, Berger TJ. Emergency departmentresource use by supervised residents vs attending physicians alone. JAMA.2014;312(22):2394-2400.2. Goldfarb S, Morrison G. The 3-year medical school—change or shortchange?N Engl J Med. 2013;369(12):1087-1089.3. Pines JM, Decker SL, Hu T. Exogenous predictors of national performancemeasures for emergency department crowding. Ann Emerg Med. 2012;60(3):293-298.4. DeLaneyM, Zimmerman KD, Strout TD, Fix ML. The effect of medicalstudents and residents onmeasures of efficiency and timeliness in an academicmedical center emergency department. AcadMed. 2013;88(11):1723-1731.5. Hiller K, Viscusi C, Beskind D, BradshawH, BerkmanM, Greene S. Cost of anacting intern: clinical productivity in the academic emergency department.J Emerg Med. 2014;47(2):216-222.6. Dehon E, McLemore G, McKenzie LK. Impact of trainees on length of stay inthe emergency department at an academic medical center. South Med J. 2015;108(5):245-248.COMMENT&RESPONSEInitial Interventions for Out-of-HospitalCardiac ArrestTo the Editor Early initiation of basic life support has beenproven to decrease mortality, which was reaffirmed byDr Malta Hansen and colleagues.1 Since the early 2000s,patients have benefited from induced hypothermia afterreturn of spontaneous circulation after cardiac arrest. A 2002study demonstrated that 49% of patients who were treatedwith hypothermia after out-of-hospital cardiac arrest sur-vived with good neurological outcomes as opposed to only26% treated with normothermia.2The studybyMaltaHansenandcolleagues,1which lookedatpatient survival andneurologicaloutcomes8yearsafterout-of-hospital cardiacarrest, didnotdifferentiateoutcomes inpa-tientswho received hypothermia vs normothermia.Wewon-der whether the authors have data regarding therapeutichypothermia and if it confounded the results of the trial.Furthermore, the definition of a bystander who per-formed cardiopulmonary resuscitation (CPR), defibrillation,or both was not discussed. There was also no explanation ofhow cardiac arrest was confirmed. In a study on rapid defi-brillation in casinos,3 patients were assessed for responsive-ness, spontaneous respirations, and palpable carotid pulse;the nearest defibrillator was then used to assess their cardiacrhythm.Malta Hansen and colleagues did not discuss how it wasdetermined whether a patient had a pulse. It also is unclearLettersjama.com (Reprinted) JAMA December 8, 2015 Volume 314, Number 22 2413Downloaded From: http://jamanetwork.com/ on 08/22/2017

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