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Chapter 44. Crew Resource Management and its Applications in Medicine
Laura Pizzi, Pharm.D.
Neil I. Goldfarb
David B. Nash, M.D., M.B.A.
Thomas Jefferson University School of Medicine and Office of Health Policy & Clinical Outcomes
Patient care, like other technically complex and high risk
fields, is an interdependent process carried out by teams of individuals with
advanced technical training who have varying roles and decision-making
responsibilities. While technical training assures proficiency at specific
tasks, it does not address the potential for errors created by communicating and
decision making in dynamic environments. Experts in aviation have developed
safety training focused on effective team management, known as Crew Resource
Management (CRM). Improvements in the safety record of commercial aviation may
be due, in part, to this training.1 Over the past 10 years, lessons
from aviation's approach to team training have been applied to patient safety,
notably in intensive care unit (ICU) and anesthesia training.2,3 This
chapter reviews the literature on Crew Resource Management, also known as
Cockpit Resource Management, and describes adaptations of this training
framework to medicine.
Crew Resource Management in Aviation
Crew Resource Management has been widely used to improve the
operation of flight crews. The concept originated in 1979, in response to a NASA
workshop that examined the role that human error plays in air
crashes.4 CRM emphasizes the role of human factors in high-stress,
high-risk environments. John K. Lauber, a psychologist member of the National
Transportation Safety Board, defined CRM as "using all available
sources—information, equipment, and people—to achieve safe and efficient flight
operations."5,6 CRM encompasses team training, as well as simulation
(also referred to as Line-Oriented Flight Training, or LOFT), interactive
group debriefings, and measurement and improvement of aircrew performance.
There is no universal CRM training program. The Federal
Aviation Administration (FAA) allows air carriers to customize their CRM
programs to best suit the needs of individual organizations. Therefore, training
programs vary somewhat from carrier to carrier, making it difficult to describe
operational components. Furthermore, these programs continue to evolve as
aviation technology changes and more is learned about group dynamics.
One CRM model focuses on the elements of human
effectiveness.7 The 3 primary components of effective crew management
are safety, efficiency, and morale. Specific factors related to aircrew
performance are categorized, and serve as the basis for training and research.
These factors include materials, organization, individual, and group process
variables associated with performance.8 Examples of outcomes that
result from these input variables are safety, efficiency, and customer
Subsequently, Helmreich and colleagues proposed a modified
conceptual framework for CRM, termed the "Error Troika,"9 to display
a hierarchy of 3 error countermeasures. At the first level, CRM includes
training on how to avoid errors. At the second level, potential errors are
"trapped" before they are committed. At the third level, mitigation of error
From a practical standpoint, CRM programs typically include
educating crews about the limitations of human performance.10
Trainees develop an understanding of cognitive errors, and how stressors (such
as fatigue, emergencies, and work overload) contribute to the occurrence of
errors. Multi-day CRM training programs typically require participants to assess
personal and peer behavior. Operational concepts stressed include inquiry,
seeking relevant operational information, advocacy, communicating proposed
actions, conflict resolution and decision making.
Prevalence and Severity of the Target Safety Problem
The field of aviation has a substantial history of collecting
and analyzing safety-related data. Historically, human error has caused or
contributed to over 50% of aviation accidents. In an analysis of 35,000 reports
of incidents over 7.5 years, almost 50% resulted from a flight crew error, and
an additional 35% were attributed to air traffic controller error.11
Root cause analyses (Chapter 5) by safety experts have found that errors
frequently occur because flight crews fail to effectively manage the resources
available to them (e.g., fail to verify information when uncertain about it, fail
to plan for contingencies).11 Naval aviation reports provide similar
results, with one study reporting 59% of "Class A mishaps" (serious consequences
including fatality, destroyed aircraft, and major injury) attributed to some
degree to aircrew factors.12 These and similar analyses have
catalyzed tailored prevention strategies including CRM for commercial
aviation,1 and "aircrew coordination training" (ACT) for Naval
Study Design and Outcomes
Although the most obvious and meaningful measure of CRM
effectiveness would appear to be airline accident or "near miss" rates, these
objective measures have not been used in commercial aviation studies. Helmreich
suggests that it is not possible to use these measures, because accident rates
are very low and "near misses" are voluntarily reported.10
Furthermore, the content and structure of CRM training programs are
In response, researchers have developed tools that assess the
effectiveness of CRM in other ways. These tools include attitudinal surveys and
peer performance rating questionnaires, including the NASA/University of Texas
Line/LOS Checklist (LINE/LOS Checklist),13 the Cockpit Management
Attitudes Questionnaire (CMAQ), and the Flight Management Attitudes
Questionnaire (FMAQ). The LINE/LOS Checklist is used to rate crew performance on
critical behaviors during specific segments of flight (e.g., not rushing through
briefing period, exhibiting high levels of vigilance in both high and low
workload conditions, etc). Ratings on each behavioral element (i.e., model for
teamwork) range across 4 levels from poor to outstanding.
In contrast, CMAQ is used to evaluate the attitudes of
crewmembers within and between organizations, pre- and/or post-CRM training.
Results are intended to serve as a proxy for measuring crew process and
performance.14 The instrument has been validated by comparing
self-reported attitudes with performance ratings made by experienced Check
Airmen, experts trained in peer evaluation.15 The FMAQ is a revised
version of the CMAQ that was developed by Helmreich and colleagues in response
to attitudinal differences observed in flight crews from different
Observation of crew performance in simulated flights has also
Several studies have utilized proxy tools to test the
effectiveness of CRM.8,12,17 One study by Helmreich and colleagues
consisted of an assessment of the attitudes before versus after CRM training
(pre-test versus post-test).17 Crew behaviors were noted by a trained
observer using the NASA/University of Texas Line/LOS Checklist.18
More than 2000 line flights and LOFT sessions were included in the analysis.
Overall performance of crews was classified as "below average," "average," or
"above average" by Check Airmen and LOFT instructors.
As a result of the CRM training, the percentage of crews rated
as "above average" increased while the percent rated "below average" decreased.
Performance ratings differed between fleets and airlines. Superior pilots also
shared many common attitudes, (for example, they were aware of their personal
limitations and diminished decision-making capacity during emergencies). In
addition, they encouraged crewmembers to question their decisions and actions,
were sensitive to the personal problems of other crewmembers, and recognized the
need to verbalize plans and to train other crewmembers.
A second study by Barker and colleagues compared the
effectiveness of 17 CRM-trained flight crews on military mission simulators,
divided according to whether they were "fixed" or "formed" crews.8
Nine of the crews were defined as "fixed" since they had flown together for six
months or longer; the remaining 8 were "formed," as they had flown together for
less than 6 months. Each crew was asked to participate in a simulated mission.
The first leg of the mission was programmed to be problem-free, but the second
leg required crews to address a safety issue. As with the earlier study, crew
behaviors were observed using the NASA/University of Texas Line/LOS Checklist.
Surprisingly, the formed crews committed fewer minor errors, but the number of
major errors did not differ significantly between the groups.8 The
authors concluded that formed crews may experience less ineffective coordination
than fixed crews, as the latter might be more complacent from the routine of
working together, but that further research was needed.
A third study evaluated rates of naval aviation mishaps, and
the role of CRM failures.12 While the study primarily compared crew
performance in 2 types of equipment, the aircrew performance deficits were also
compared with those seen during an earlier time period, prior to implementation
of aircrew coordinating training (ACT) programs (the specific form of CRM used).
Analysis of data from the post-ACT implementation period across the fleet
revealed that 70% of human error mishaps were connected with aircrew factors,
and that 56% of these resulted from at least one CRM failure. The authors noted
that these percentages were similar to those reported in a separate study prior
to ACT implementation. Because of a lack of controls or adjustments for
potential confounders, no conclusions about effectiveness of the ACT program can
Comparison to Medicine
Sexton and colleagues compared flight crews with operating room
personnel on several measures, including attitudes toward teamwork.19
The study included more than 30,000 cockpit crew members (captains, first
officers, and second officers) and 1033 operating room personnel (attending
surgeons, attending anesthesiologists, surgical residents, anesthesia residents,
surgical nurses, anesthesia nurses). Data from the crew members were obtained
from previous administrations of the CMAQ and FMAQ to major airlines around the
world (over a 15-year period). The operating room participants were mailed an
analogous questionnaire (CMAQ modified20), administered over a period
of 3 years at 12 teaching and non-teaching hospitals in the United States and
abroad (Italy, Germany, Switzerland, and Israel).
The level of teamwork perceived by attending surgeons compared
with other operating room staff differed markedly. A majority of surgical
residents (73%) and attending surgeons (64%) reported high levels of teamwork,
but only 39% of attending anesthesiologists, 28% of surgical nurses, 25% of
anesthesia nurses, and 10% of anesthesia residents reported high levels of
teamwork. A bare majority (55%) of attending surgeons rejected steep hierarchies
(determined by whether they thought junior team members should question the
decisions of senior team members). In contrast, 94% of airline crew members
preferred flat hierarchies.
It was also noted that medical participants were far more
likely to agree with the statement "Even when fatigued, I perform effectively
during critical times." Seventy percent of attending surgeons agreed with this
statement, as well as 56% of surgical residents, 60% of surgical nurses, 57% of
anesthesia residents, 55% of anesthesia nurses, and 47% of attending
anesthesiologists. In contrast, 26% of pilots agreed with this statement.
Applications of CRM Principles in Medicine
The Sexton study and other analyses suggest that safety-related
behaviors that have been applied and studied extensively in the aviation
industry may also be relevant in healthcare. We identified CRM applications in
several dynamic decision-making healthcare environments: the operating room,
labor and delivery, and the emergency room.3,21,22 In addition, Gaba
has noted that some other domains (e.g., cardiac arrest response teams) that have
active simulation training are currently incorporating a broader range of
CRM-like training methods.23 (Simulators are covered in more detail
in Chapter 45).
Crew Resource Management in Healthcare Settings
As with aviation, the medical application of CRM has required
tailoring of training approaches to mirror the areas in which human factors
contribute to mishaps. In anesthesiology 65-70% of safety problems (accidents or
incidents) have been attributed at least in part to human error. In response,
several anesthesiologists from the VA Palo Alto Health Care System and Stanford
University, with funding from the Anesthesia Patient Safety Foundation,
developed Anesthesia Crisis Resource Management (ACRM), modeled on
CRM.3,23 The original demonstration courses consisted of didactic
instruction, videotape of a reenactment of an aviation disaster, videotape of an
actual anesthetic mishap, simulation training and a debriefing session. Ongoing
courses include the use of a textbook that catalogues 83 critical events (e.g.,
acute hemorrhage, bronchospasm, seizures), and approaches to managing
them.24 Currently, there are 3 ACRM courses offering progressively
more challenging material, a Working Group on Crisis Management Training in
Health Care formed by the developers of ACRM that has initiated formal ACRM
instructor training, and thoughtful consideration of pragmatic approaches to
Helmreich and Schaefer have also advanced CRM theory in the
operating room environment by adapting their model of team performance. This
framework describes the team performance inputs that are critical to essential
team functions that in turn lead to desired outcomes (defined as patient
well-being). Examples of inputs include individual aptitudes, physical
environment, and culture (professional, organizational, and national).
Performance functions consist of team formation and management, surgical
procedures, communications, decision processes, and situational
Another application of CRM to the health environment is the
MedTeams behavior-based teamwork system, developed by Dynamics Research
Corporation, and sponsored by the Army Research Laboratory. It aims to adapt
research in team performance and training from military helicopter aviation to
emergency medicine.22,25,26 Thus far, specific applications have been
developed for Emergency Department care and labor and delivery
units.27 The system is implemented through courses and assessment
tools. The Emergency Team Coordination Course (ETCC) includes 5 team dimensions
or goals (i.e., maintain team structure and climate, facilitate planning and
problem-solving, enhance communication among team members, facilitate workload
management, improve team-building skills). Each goal is tied to specific
teamwork tasks. For example, tasks for the first goal (maintain team structure
and climate) include "establish team leader," "form the team," "set team goals,"
and "assign roles and responsibilities."22 Like the CRM approach to
the "Error Troika," the MedTeams approach is based on avoiding errors, trapping
them as they occur, and mitigating the consequences of actual errors. Principles
underlying the MedTeams approach include:
- Team responsibility for patients.
- A belief in clinician fallibility.
- Peer monitoring.
- Team member awareness of patient status, team member status and
Peer monitoring is a fundamental component of the MedTeams
system, as well as a feature of the ACRM and aviation field's CRM approaches.
Along with his or her clinical responsibilities, each team member undertakes the
intermittent process of peer monitoring or "check" actions, engaging in this
check cycle as frequently as possible. The teamwork check cycle begins with each
team member monitoring his or her own situation awareness and cross-monitoring
the actions of other teammates. If during the monitoring mode the
monitoring teammate observes a suspected error in progress, that
individual intervenes with a direct question or offer of information. The erring
teammate may then acknowledge the lapse, correct it and continue working.
Alternatively, the monitoring teammate may have lost situation awareness.
The non-erring monitored colleague can then provide feedback to correct
the peer's situation awareness. If team members are in strong disagreement about
how patient care should proceed, advocacy, assertion and perhaps third-party
involvement may be used to resolve the situation. Over time, the check cycle
becomes habitual, resulting in hundreds of team checks daily, all with the
potential to break the error chain.
Recently, ACRM has been extended to a full-day course on
neonatal resuscitation training for neonatologists and
pediatricians.21 Called "NeoSim", the course combines traditional
training methods with reviews of literature and didactic instruction with
simulation. Debriefing follows, using videotape of the simulation. As with the
other examples, the emphasis of teaching behavioral teamwork skills along with
technical content is the hallmark of CRM interventions in healthcare.
Evidence for Effectiveness of the Practice
The most thoroughly studied of the medical CRM applications is
ACRM, although as with the aviation examples, rigorous evaluations are
challenging to design. Few studies utilize a control group, although researchers
have reported assessment methods for determining both technical and behavioral
performance from simulator videotapes28 (see also Chapter 45). A
before-after ACRM training analysis (Level 3 Study Design) of trainees'
knowledge-base (Level 3 Outcome) for crisis yielded mixed results.3
The average score on the post-test was significantly greater than the pre-test
for one trainee class, composed mostly of residents. For the other class of
experienced anesthesiologists, the test scores did not change and were at the
same level as the post-test scores of class of residents. Subjective data
evaluating the course indicated that trainees "uniformly felt that the ACRM
course was an intense, superior form of training related to an important, but
inadequately taught, component of anesthesia practice."3 Another
study of ACRM at Harvard also found that participants rated the course
favorably, with over 80% responding that they felt the course should be taken
every 24 months or less.29
As with aviation, the incremental value of this form of
training is difficult to link to improvements in teamwork performance and better
safety records. At the time of this literature assessment, there were no
published data to describe the effects on medical error rates of the MedTeams
approach. The NeoSim course participants provided positive responses to
open-ended questions about their satisfaction with the
Costs and Implementation
Helmreich has noted some of the limitations associated with
CRM.10 At this time, the evidence connecting CRM approaches to
improving patient safety does not exist, notwithstanding the face validity of
the approach. Nevertheless, a long history of variants of the approach offers
healthcare a reasonable foundation from which to draw practical and
evidenced-based resources30 for further development and adaptation of
CRM, as well as measurement methods to ascertain its effectiveness.
At a minimum, implementation of the CRM approach in healthcare
settings requires customization of tools and techniques for each specific care
venue, as is illustrated by adaptations implemented thus far. This customization
comes at considerable cost and cannot be expected to immediately reap safety
benefits. At the time of this review, approximate costs for implementing the
MedTeams system ranged from $15,000-$35,000, with additional costs for ongoing
activities (such as continuing education) that ranged from $8,000-$20,000
(R. Simon, personal communication, April 2001). Similarly, marginal costs for
CRM-like training based on the ACRM experience are estimated at $800 to $2,000
per participant per day (D. M. Gaba, personal communication, June 2001). These
costs do not include the overhead of starting a program (e.g., simulator
investment, training instructors), nor do they factor in the cost of reduced
practice work hours, if these are above those devoted to current training
Cultural shifts in medicine are also necessary if the CRM
approach is truly to take root. CRM applications are relatively novel in
healthcare, a field in which professional training and education have
traditionally focused on developing technical proficiency rather than
facilitating human interaction. Although communication and decision making are
central to medical practice, relatively little about this topic has appeared in
medical literature, despite the fact that information flow is critical,
particularly in high acuity venues such as the operating room and emergency
departments. Ideas must be elicited, debated and evaluated without
discrimination based on the status of the staff person offering the
Paradoxically, the attachment to hierarchy may be the reason
that a small percentage of participants can be expected to reject CRM training.
Research has shown that some resistance is rooted in personality
characteristics. Crew members lacking in achievement motivation and
interpersonal skills are more likely to reject the training. Additionally, CRM
practices decay over time, even with repeated training, requiring continuing
expenditures to retain the hoped-for gains.10
CRM has evolved in the airline industry for more than 20 years,
and has been extensively applied during the past decade. Although no definitive
data link CRM to decreased aviation error per se, the industry has
accepted the face validity of the practice, and it is now an integral part of
training. Over time, survey data from thousands of civilian and military
participants in the United States and abroad has been accrued. These data
indicate that most flight crew members accept CRM training, and find it both
relevant and useful.7
The studies reviewed provide some support for the notion that
CRM is worth further investigation in healthcare. However, it cannot yet be
concluded that CRM is a practice that can reduce medical errors. Additional
research in this area is warranted, although measurement and study design are
particularly challenging. As noted, although the evidence from aviation, where
CRM is well-established, has shortcomings, data are easier to capture since CRM
assessments can be grafted onto mandatory, ongoing, yearly pilot assessments
conducted both in simulators and in real flights (D. M. Gaba, personal
communication, June 2001). In medicine, where ongoing assessments are not the
norm, capturing relevant data will be more difficult logistically and much more
expensive than in aviation. Consequently, and for the analogous reasons that
aviation has adopted CRM based on face validity, healthcare decision makers may
wish to consider face validity in lieu of massive research investments.
Nonetheless, evaluations of CRM that focus on intermediate
outcomes (e.g., trainee performance) are feasible, and instructive for optimizing
components of CRM programs. CRM design and evaluation resources are becoming
more widely available,30 and healthcare should continue to consult
these sources, building on the advances made in other fields.
The authors are grateful to Robert Simon, Chief Scientist at
Dynamics Research Corporation, for providing details on the MedTeams
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