CHEST / 141 / 5 / MAY, 2012 1315
clinicians and the safety of the patients for whom they
are responsible. 1 Whenever clinicians empower train -
ees to make decisions or perform procedures on their
patients, they abrogate the traditional notion that a
physician’s primary obligation is to his or her current
patients. This exception to traditional professional
edical education entails an inherent tension
between the training needs of inexperienced
ethos has persisted for generations, 2 either because it
has been opaque to most onlookers or because soci-
ety implicitly accepts that small sacrifi ces in the care
of current patients are reasonable and necessary to
maintain competent physicians year after year.
Despite a confl uence of ethical, legal, and eco-
nomic support for the notion that physicians cannot
avoid their dual roles as agents of society and guard-
ians of their current patients’ best interests, 3-5 recent
trends in teaching hospitals have slowly but surely
shifted the balance toward the latter role in unbri-
dled efforts to promote the safety of current patients.
A dramatic example of this trend is the rapid increase
in the proportion of academic ICUs that provide
around-the-clock staffi ng with attending physicians
trained in critical care. This model of 24-h inten-
sivist staffi ng offers several potential benefi ts for
patients and health-care providers alike: (1) greater
patient safety and operational effi ciency stemming
from more experienced clinical decision making and
procedural performance, (2) increased patient and
family satisfaction from the immediate availabil-
ity of a trained critical care specialist, (3) reduced
burnout among attending physicians if models are
There is an inherent tension between the training needs of inexperienced clinicians and the
safety of the patients for whom they are responsible. Our society has accepted this tension as a
necessary trade-off to maintain a competent workforce of physicians year after year. However,
recent trends in medical education have diminished resident autonomy in favor of the safety of
current patients. One dramatic example is the rapid increase in the number of academic ICUs
that provide coverage by attending physicians at all hours. The potential benefi ts of this staffi ng
model have strong face validity: improved quality and effi ciency from the constant involvement
of experienced intensivists, increased family and staff satisfaction from the immediate availability
of attending physicians, and reduced burn-out among intensivists from reduced on-call responsi-
bilities. Thus, many hospitals have moved toward 24-h coverage by attending intensivist physi-
cians without evidence that these benefi ts actually accrue and perhaps without full consideration
of possible unintended consequences. In this article, we discuss the potential benefi ts and risks of
nocturnal intensivist staffi ng, considering the needs of current and future patients. Furthermore,
we suggest that there remains suffi cient uncertainty about these benefi ts and risks that it is both
necessary and ethical to study the effects in earnest. CHEST 2012; 141(5):1315–1320
Twenty-four-Hour Intensivist Staffi ng
in Teaching Hospitals
Tensions Between Safety Today and Safety Tomorrow
Meeta Prasad Kerlin , MD , MSCE ; and Scott D. Halpern , MD, PhD
Manuscript received June 10, 2011; revision accepted November 28,
Affi liations: From the Division of Pulmonary, Allergy, and Crit-
ical Care Medicine (Drs Kerlin and Halpern); the Center for
Clinical Epidemiology and Biostatistics (Dr Halpern), Leonard
Davis Institute of Health Economics (Dr Halpern); and the Cen-
ter for Bioethics (Dr Halpern), Perelman School of Medicine at
the University of Pennsylvania, Philadelphia, PA.
Funding/Support: Dr Halpern is supported by the Agency
for Healthcare Research and Quality [K08HS018406] and the
National Institutes of Health [R01 CA159932] .
Correspondence to: Meeta Prasad Kerlin, MD, MSCE, Division
of Pulmonary, Allergy, and Critical Care Medicine, 3600 Spruce St,
8th Floor, Gates Bldg, Philadelphia, PA 19104; e-mail: prasadm@
© 2012 American College of Chest Physicians. Reproduction
of this article is prohibited without written permission from the
American College of Chest Physicians ( http://www.chestpubs.org/
Patient Safety Is at Risk in
our Health-care System
In 1999, the Institute of Medicine published To Err
Is Human , calling new attention to medical errors
in the US health system. 8 The report brought patient
safety to the forefront of health services research,
national policy development, and public attention.
The Institute of Medicine spelled out the conse-
quences of medical errors, including direct harm to
patients, increased health-care expenditures, and
decreased confi dence in the US health-care sys-
tem. In short, the Institute of Medicine effectively
demanded change by exposing the vulnerabilities and
shortcomings of the prevailing models of health-care
Responses to this call to action have come from
every direction as multiple stakeholders have scruti-
nized the system to fi nd opportunities for improve-
ment. For example, the Joint Commission established
the National Patient Safety Goals program in 2002 to
broadly improve safety standards for all health-care
settings, 9 revamping the accreditation process for
US hospitals. Patients and their families have orga-
nized into advocacy and safety champions, gaining
voices in the media and power in legislative and policy
decisions. The Accreditation Council for Graduate
Medical Education placed limits on resident work
hours, in part to respond to patient safety concerns
that arose with high-profile cases 10 and clinical
research 11 that suggested that trainee fatigue could
increase clinical errors. The Leapfrog Group advo-
cated certain standards of intensivist staffi ng in ICUs
without clear evidence to support their recommen-
dations. 12 Making attending intensivists available at
all times in ICUs is merely one of the latest ideas
intended to improve patient safety.
Benefits of 24-h Intensivist
Staffing to Patients Today
Twenty-four-hour intensivist staffi ng could ben-
efi t patients directly and indirectly. It is logical, for
example, that a specialty-trained, experienced clinician
would provide optimal diagnostic acumen and thera-
peutic competency in managing critically ill patients.
Continuous availability of an intensivist may lead to
more timely and accurate diagnostic evaluation and
appropriate therapeutic decisions, leading to higher
quality, safer, and more effi cient care. Some have also
raised the possibility that care might be less costly
with 24-h intensivist staffi ng if patients’ lengths of stay
were reduced. 13 And indeed, several studies suggest
that patients in ICUs with “high-intensity” critical care
physician staffi ng (ie, ICUs that require either trans-
fer of care to, or mandatory consult of, an attending
implemented to provide more manageable hours and
clinical responsibilities, and (4) reduced burnout among
bedside nurses whose advocacy for their patients may
be fostered by the onsite presence of more senior
Because these potential benefi ts have such strong
face validity, 24-h in-hospital intensivist staffi ng has
been implemented in many academic institutions,
despite the lack of evidence that these benefi ts actu-
ally accrue, and perhaps without full consideration
of this policy’s potential downsides. One risk of noc-
turnal intensivist staffi ng involves resident autonomy.
Experiential learning has unquestionable value in
medical training, and the presence of constant super-
vision by an attending physician could improve the
learning experiences of trainees through greater
exposure to bedside teaching, immediate feedback to
trainees, and real-time refi nement of clinical deci-
sions. However, if increased supervision leads to a
more passive roles for trainees, fewer opportunities
to make decisions, and a reduced sense of personal
responsibility for patients’ welfare, greater supervi-
sion today could reduce the quality of the physician
workforce tomorrow. Will residents exit their training
with less confi dence and competence without having
been empowered to “run the unit” (typically with
tele phone backup) at night? The current shortage
of trained intensivists, insuffi cient to staff all ICUs
even during daytime hours, 6 raises a second risk in
rapidly implementing 24-h attending physician staff-
ing: that it may exacerbate existing disparities in
health-care access, because the more prosperous
hospitals attract disproportionate numbers of special-
ists, leaving increas ing numbers of other institutions
with inadequate coverage or none at all. Third, as
has happened with implementation of resident work
hours reforms, 7 broad implementation of 24-h inten-
sivist staffi ng could lead to its acceptance as the
standard of care, precluding experimental evalua-
tion of either its intended or unintended effects,
thereby sabotaging opportunities to improve on the
Against this backdrop, this essay has two central
goals. First, we seek to provide a normative justifi ca-
tion for considering the safety of all patients, those
of today and those of tomorrow, when making ICU
staffi ng decisions. In doing so, we provide a frame-
work for balancing the needs of medical education
and patient safety in the ICU. Second, we suggest that
despite its many potential benefi ts and increasing
implementation, there remains suffi cient uncertainty
regarding the pros and cons of 24-h intensivist staff-
ing that it remains ethically acceptable to study its
effects in earnest, including through randomized
assignment of patients to 24-h vs daytime intensivist
CHEST / 141 / 5 / MAY, 2012 1317
US ICUs lack intensivists entirely. 6 Although some of
these units care primarily for lower-acuity patients
admitted to the ICU for monitoring purposes, risks
to occasional higher-acuity patients remain because
these ICUs are disproportionately located in regions
where access to health care is reduced more gener-
ally. Moving toward 24-h intensivist staffi ng may pull
even more specialists away from hospitals where they
are already sparse, thereby widening the variability in
quality of care across the health system. Academic
hospitals and hospitals located in more prosperous
regions may be able to increase staffi ng suffi ciently
to provide attending intensivists around the clock,
but with relatively fi xed supplies of ICU-trained phy-
sicians, nurses, and other professionals, this trend
widens existing chasms in care.
Though perhaps more diffi cult to predict, 24-h
intensivist staffi ng also poses risks to patients in the
future. It is unknown what the effect of having
attending physicians in the hospital at all hours will
be on medical education. Would reduction in stress
for the resident result from increased supervision and
more immediate bedside teaching result in improved
learning during overnight shifts? Or would dimin-
ishing trainee autonomy reduce competency as resi-
dents are less often positioned to make their own
clinical decisions? Adult education theory is unequiv-
ocal: we learn by doing. If trainees are never forced
to “do,” there is a risk that they will leave their resi-
dencies with less confi dence and skill as they enter
the workforce as independent practitioners, compro-
mising the quality of care for the patients of tomor-
row. Although 24-h intensivist staffi ng may improve
some components of education by providing more
opportunities for trainees to directly observe and
partner with experienced clinicians in action, such
potential benefi ts would only accrue if these new
shift-work intensivists inculcate education as part of
their mission. Clearly, evidence is needed to deter-
mine the overall impact on trainees.
The fundamental change in the educational environ-
ment of an ICU that will occur with 24-h inten sivists
may also change the pattern of recruiting trainees
into critical care. If the residents’ loss of autonomy
translates into a less engaging and enjoyable experi-
ence during general training, there is a risk that fewer
trainees will choose to pursue careers as intensivists
themselves, potentially resulting in an even greater
disparity between the supply of and demand for crit-
ical care practitioners. 25 If we believe that intensivists
provide better care to critically ill patients, then
moving toward 24-h intensivist staffi ng paradoxically
may compromise the quality of our health care in the
future. Alternatively, the more regular hours afforded
intensivists working in 24-h staffi ng units might moti-
vate trainees to pursue careers in critical care, because
intensivist), experience reduced mortality and length
of stay compared with patients admitted to ICUs
with other staffi ng models. 14,15 Although at least one
high-profi le study suggested harm with high-intensity
staffi ng, particularly among low-risk patients, 16 meth-
odologic concerns have been raised with this study, 17
and the bulk of observational data continues to favor
high-intensity staffi ng. 15
Also generally accepted in critical care is the impor-
tance of the “golden” hours, the early period of crit-
ical illness when timely interventions may improve
outcomes. 18-20 Thus, attention by a clinician who can
make assessments and implement appropriate ther-
apies in the middle of the night, rather than defer-
ring them until the morning, holds clear potential to
improve patient outcomes. In support of this argu-
ment are several studies that suggest worse outcomes
for patients admitted during nighttime or weekend
hours, although a recent systematic review found
substantial heterogeneity among the single-center
Indirect benefi ts to patients may also favor 24-h
intensivist staffi ng. Improved team building may
result from increased satisfaction of the nursing
staff and physicians themselves with a continuous-
coverage model. From a survey of critical care nurses,
many reported a perception of communication delays
when a covering physician must be reached by phone,
and a greater likelihood of alerting physicians to a
change in a patient’s status if the physician is physi-
cally present. 22 Increased satisfaction in the domains
of patient care, relations and communications, and
education were noted by allied health staff (including
nurses, pharmacists, and respiratory therapists) after
a transition to a continuous attending staffi ng model
in one academic ICU. 23 Physicians in the same ICU
agreed that communications and relations were better,
and expressed a reduced sense or fear of burn-out.
These positive changes may translate into benefi ts for
patients today, because better integration of care across
disciplines may improve outcomes. 24 They may also
portend benefi ts for patients tomorrow. If 24-h staffi ng
models are implemented in ways that reduce burn-
out among ICU physicians, they may be better able
to continue providing critical care well into the more
experienced portions of their careers.
Unintended Consequences of
24-h Intensivist Staffing for
Patients Today and Tomorrow
Before establishing 24-h intensivist staffi ng as the
standard of care, however, several plausible down-
sides to this model merit consideration. First, the cur-
rent supply of intensivists is insuffi cient to meet
the demands of all critically ill patients. Indeed, many
higher level of evidence before bringing to market a
new drug that might affect outcomes for a few thou-
sand patients per year than before implementing
a policy change likely to affect tens of millions of
patients annually. We have heard colleagues suggest
that one could not conduct a prospective controlled
study of 24-h intensivist staffi ng because clinical equi-
poise 32 no longer exists; a randomized trial of this
staffi ng model would seem to be out of the question.
However, despite the fact that the train of 24-h
intensivist staffi ng has already left the station, and
that the model has a certain degree of face validity,
there is as yet little evidence to support such change.
The existing knowledge base stems from two retro-
spective, single-center, observational studies using
historical controls with limited adjustments for sec-
ular trends. 23,33 Even if substantive improvements in
care had been noted in these studies (none were),
these methodologic features would limit our ability
to draw meaningful inferences regarding the staffi ng
model’s effects. Further, such limitations cloud inter-
pretation of the one study examining the economic
effects of 24-h staffi ng 13 because of its reliance on the
same data. Finally, because of the absence of data
regarding processes of care, and these studies’ poor
specifi cation of nocturnal intensivists’ actual roles, we
have little basis upon which to decipher mechanisms
of effects or to replicate such effects in other settings.
For a largely benign policy change, perhaps rea-
sonable face validity, evolving practice patterns, and
a paucity of evidence would suffi ce. But given the
poten tially large incremental costs and educational
downsides to 24-h intensivist staffi ng, it seems that
we should, at a bare minimum, be certain that the
purported short-term benefi ts actually manifest. Ide-
ally, such studies would also be designed to provide
pre liminary insights into some of the unintended
consequences of this staffi ng change, such as whether
it increases regional disparities in access to inten-
sivists or erodes the competence of future clinicians.
Understanding intermediate-term changes in the
recruitment and retention of critical care physicians
and nurses would also help provide a robust under-
standing of the comparative effectiveness of ICU
staffi ng models.
Thus, although some may feel that clinical equi-
poise, a state of genuine uncertainty among expert
clinicians regarding the comparative merits of two or
more interventions, 32 no longer exists, more modern
con ceptualizations of equipoise remain intact. Spe-
cifi cally, “evidence-based equipoise” 34 has not been
broached; the superiority of one approach has yet to
be supported by high-level evidence. Further, what has
recently been termed “behavioral equipoise” 35 most
certainly exists; by this standard, future interventional
studies are precluded only when high-level evidence
such careers start to appear more manageable. Further,
more immediate feedback and teaching at night may
provide a more satisfying learning experience for train-
ees, which could also enhance the attrac tiveness of a
crit ical care career.
A Framework to Balance the Safety
of our Patients Today With the
Needs of our Patients Tomorrow
How ought we to balance potential benefi ts and
harms to readily identifi able critically ill patients vs the
anonymous but larger group of patients at risk of
future critical illness? As noted, the implicit rationale
underlying medical education is that the individual
good may, on occasion, be sacrifi ced for purposes of
broader social good. 1 Organ allocation provides an
example of how we make such tradeoffs. Recipient
selection is not guided merely by the desire to maxi-
mize benefi ts for those at the top of waitlists, but also
by our shared social values of promoting equity in
access and maximizing total benefi ts across the pool
of potential recipients in the face of a limited organ
supply. 26,27 Allocation of ICU beds also tends to follow
a strategy of maximizing the “greater” good rather
than the individual good. When ICUs are particularly
busy, patients are often discharged sooner to accom-
modate more patients, 28,29 and such prematurely dis-
charged patients experience greater risks of clinical
decompensation requiring ICU read mission. 29-31 This
suggests that we are willing to tolerate some indi-
vidual harm in order to provide critical care services
to a greater number of patients.
Our willingness to sacrifi ce some degree of benefi t
for identifi able patients to promote greater net social
benefi t over the long term in the domains of medical
education and the allocation of transplantable organs
and ICU beds establishes a precedent for a similar
approach to intensivist staffi ng. However, given the
multiple potential advantages and disadvantages of
24-h intensivist staffi ng, much of the argument is
entirely speculative. An evidence-based approach is
needed to determine how best to balance the safety of
patients today with the needs of patients tomorrow,
and to better understand the cost-benefi t ratios of
24-h intensivist staffi ng for individual patients, prac-
titioners, trainees, and society.
Studying 24-h Intensivist Staffing:
Does Equipoise Exist?
Robust outcomes research clearly can inform the
wisdom of interventions that could amount to major
shifts in medical care, expenditures, and education.
Yet, somewhat ironically, we tend to require a much
CHEST / 141 / 5 / MAY, 2012 1319
3 . Fuchs VR . The doctor’s dilemma—what is “appropriate” care?
N Engl J Med . 2011 ; 365 ( 7 ): 585 - 587 .
4 . Bloche MG . Clinical loyalties and the social purposes of med-
icine . JAMA . 1999 ; 281 ( 3 ): 268 - 274 .
5 . Bloche MGUS . U.S. health care after Pegram: betrayal at the
bedside? Health Aff (Millwood) . 2000 ; 19 ( 5 ): 224 - 227 .
6 . Angus DC , Shorr AF , White A , Dremsizov TT , Schmitz RJ ,
Kelley MA ; Committee on Manpower for Pulmonary and
Critical Care Societies (COMPACCS) . Critical care delivery in
the United States: distribution of services and compliance
with Leapfrog recommendations . Crit Care Med . 2006 ; 34 ( 4 ):
1016 - 1024 .
7 . Volpp KG , Friedman W , Romano PS , Rosen A , Silber JH .
Residency training at a crossroads: duty-hour standards 2010 .
Ann Intern Med . 2010 ; 153 ( 12 ): 826 - 828 .
8 . Kohn KTCJ , Donaldson MS . To Err Is Human: Building a
Safer Health System . Washington, DC : National Academy
Press ; 1999 .
9 . National patient safety goals . 2008 . The Joint Commission
web site. http://www.jointcommission.org/PatientSafety/National
PatientSafetyGoals/ . Accessed September 17, 2008.
10 . Asch DA , Parker RM . The Libby Zion case. One step for-
ward or two steps backward? N Engl J Med . 1988 ; 318 ( 12 ):
771 - 775 .
11 . Landrigan CP , Rothschild JM , Cronin JW , et al . Effect of
reducing interns’ work hours on serious medical errors in
intensive care units . N Engl J Med . 2004 ; 351 ( 18 ): 1838 - 1848 .
12 . The Leapfrog Group . Factsheet: ICU physician staffi ng.
Leapfrog Group website. http://www.leapfroggroup.org/
media/fi le/Leapfrog-ICU_Physician_Staffi ng_Fact_Sheet.pdf .
Accessed September 29 2011.
13 . Banerjee R , Naessens JM , Seferian EG , et al . Economic
implications of nighttime attending intensivist coverage in
a medical intensive care unit . Crit Care Med . 2011 ; 39 ( 6 ):
1257 - 1262 .
14 . Gajic O , Afessa B . Physician staffi ng models and patient safety
in the ICU . Chest . 2009 ; 135 ( 4 ): 1038 - 1044 .
15 . Pronovost PJ , Angus DC , Dorman T , Robinson KA ,
Dremsizov TT , Young TL . Physician staffi ng patterns and
clinical outcomes in critically ill patients: a systematic review .
JAMA . 2002 ; 288 ( 17 ): 2151 - 2162 .
16 . Levy MM , Rapoport J , Lemeshow S , Chalfi n DB , Phillips G ,
Danis M . Association between critical care physician man-
agement and patient mortality in the intensive care unit .
Ann Intern Med . 2008 ; 148 ( 11 ): 801 - 809 .
17 . Rubenfeld GD , Angus DC . Are intensivists safe? Ann Intern
Med . 2008 ; 148 ( 11 ): 877 - 879 .
18 . Rivers E , Nguyen B , Havstad S , et al ; Early Goal-Directed
Therapy Collaborative Group . Early goal-directed therapy in
the treatment of severe sepsis and septic shock . N Engl J Med .
2001 ; 345 ( 19 ): 1368 - 1377 .
19 . Dellinger RP , Carlet JM , Masur H , et al ; Surviving Sepsis
Campaign Management Guidelines Committee . Surviving
Sepsis Campaign guidelines for management of severe sepsis
and septic shock [published correction appears in Crit Care
Med. 2004;32(6):1448] . Crit Care Med . 2004 ; 32 ( 3 ): 858 - 873 .
20 . De Luca G , Suryapranata H , Ottervanger JP , Antman EM .
Time delay to treatment and mortality in primary angioplasty
for acute myocardial infarction: every minute of delay counts .
Circulation . 2004 ; 109 ( 10 ): 1223 - 1225 .
21 . Cavallazzi R , Marik PE , Hirani A , Pachinburavan M , Vasu TS ,
Leiby BE . Association between time of admission to the ICU
and mortality: a systematic review and metaanalysis . Chest .
2010 ; 138 ( 1 ): 68 - 75 .
22 . Lindell KO , Chlan LL , Hoffman LA . Nursing perspectives
on 24/7 intensivist coverage . Am J Respir Crit Care Med .
2010 ; 182 ( 11 ): 1338 - 1340 .
exists to support one intervention and clinicians
are nearly uniformly convinced by this evidence
(as opposed to the perhaps more common situation in
which a major trial leads to some advocates and some
critics of the new approach). Therefore, although this
window of equipoise exists, and considering the sub-
stantive stakes of the decision, we believe it is impera-
tive to initiate prospective, randomized trials of 24-h
vs daytime-only intensivist physician staffi ng. This is
not to suggest that institutions that have adopted
24-h staffi ng should drop this model pending such
evidence, any more than institutions that have not
adopted it should be required to do so. Instead, the
conclusion is that research is both needed and jus-
tifi ed and, once it is available, could inform the
decisions of both types of institutions. Otherwise, as
pro gres sively more stakeholders take sides on this
debate, the perception that broad coverage equals
better care may trump reasoned skepticism, remov-
ing the remaining opportunities to study the model
There are important tradeoffs inherent in many
strategies designed to improve patient safety, where
unintended consequences may, on balance, harm
broad populations of present or future patients despite
benefiting certain currently identifiable patients.
Using the example of 24-h coverage by attending
physicians in ICUs, we have discussed the nature
of these potential tradeoffs, suggested that impacts
on both today’s and tomorrow’s patients be consid-
ered, and provided justifi cation for studying this staff-
ing model in earnest. We may well learn that 24-h
intensivist staffi ng has substantial benefi ts across many
relevant domains and should be adopted as broadly
as possible. But if we do not seize the present oppor-
tunity to study the concept in randomized fashion,
we risk eternal blindness to a deleterious and costly
standard of care.
Financial /nonfi nancial disclosures: The authors have reported
to CHEST the following confl icts of interest: Dr Kerlin receives
support from the Centers for Disease Control and Prevention
for a project unrelated to this manuscript. Dr Halpern receives
support from the National Institutes of Health for a project unre-
lated to this manuscript.
Role of sponsors : The sponsors had no role in the design of the
study, the collection and analysis of the data, or in the preparation
of the manuscript.
1 . Chiong W . Justifying patient risks associated with medical
education . JAMA . 2007 ; 298 ( 9 ): 1046 - 1048 .
2 . Bloche M . The Hippocratic Myth: Why Doctors Are Under
Pressure to Ration Care, Practice Politics, and Compromise Their
Promise to Heal . New York, NY : Pallgrave-MacMillian ; 2011 .
1320 Download full-text
23 . Gajic O , Afessa B , Hanson AC , et al . Effect of 24-hour
mandatory versus on-demand critical care specialist presence
on quality of care and family and provider satisfaction in
the intensive care unit of a teaching hospital . Crit Care Med .
2008 ; 36 ( 1 ): 36 - 44 .
24 . Kim MM , Barnato AE , Angus DC , Fleisher LA , Kahn JM .
The effect of multidisciplinary care teams on intensive care
unit mortality [published correction appears in Arch Intern
Med . 2010;170(10):867] . Arch Intern Med . 2010 ; 170 ( 4 ):
369 - 376 .
25 . Krell K . Critical care workforce . Crit Care Med . 2008 ; 36 ( 4 ):
1350 - 1353 .
26 . Munson JC , Christie JD , Halpern SD. The societal impact of
single versus bilateral lung transplantation for chronic obstruc-
tive pulmonary disease. Am J Respir Crit Care Med . 2011 ;
184 ( 11 ): 1282 - 1288 .
27 . Halpern SD , Shaked A , Hasz RD , Caplan AL . Informing
candidates for solid-organ transplantation about donor risk
factors . N Engl J Med . 2008 ; 358 ( 26 ): 2832 - 2837 .
28 . Strauss MJ , LoGerfo JP , Yeltatzie JA , Temkin N , Hudson LD .
Rationing of intensive care unit services. An everyday occur-
rence . JAMA . 1986 ; 255 ( 9 ): 1143 - 1146 .
29 . Diwas KC , Terwiesch C . An econometric analysis of patient
fl ows in the cardiac ICU. Standford Graduate School of Business
documents/oit_03_08_diwas.pdf . Accessed April 5, 2011.
30 . Baker DR , Pronovost PJ , Morlock LL , Geocadin RG ,
Holzmueller CG . Patient fl ow variability and unplanned read-
missions to an intensive care unit . Crit Care Med . 2009 ; 37 ( 11 ):
2882 - 2887 .
31 . Chrusch CA , Olafson KP , McMillan PM , Roberts DE ,
Gray PR . High occupancy increases the risk of early death
or readmission after transfer from intensive care . Crit Care
Med . 2009 ; 37 ( 10 ): 2753 - 2758 .
32 . Freedman B . Equipoise and the ethics of clinical research .
N Engl J Med . 1987 ; 317 ( 3 ): 141 - 145 .
33 . Blunt MC , Burchett KR . Out-of-hours consultant cover and
case-mix-adjusted mortality in intensive care . Lancet . 2000 ;
356 ( 9231 ): 735 - 736 .
34 . Halpern SD . Evidence-based equipoise and research respon-
siveness . Am J Bioeth . 2006 ; 6 ( 4 ): 1 - 4 .
35 . Ubel PA , Silbergleit R . Behavioral equipoise: a way to resolve
ethical stalemates in clinical research . Am J Bioeth . 2011 ;
11 ( 2 ): 1 - 8 .