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Human Factors Engineering
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An obstetric nurse connects a bag of pain medication intended for an epidural catheter to the mother's intravenous (IV) line, resulting in a fatal cardiac arrest. Newborns in a neonatal intensive care unit are given full-dose heparin instead of low-dose flushes, leading to three deaths from intracranial bleeding. An elderly man experiences cardiac arrest while hospitalized, but when the code blue team arrives, they are unable to administer a potentially life-saving shock because the defibrillator pads and the defibrillator itself cannot be physically connected.

Busy health care workers rely on equipment to carry out life-saving interventions, with the underlying assumption that technology will improve outcomes. But as these examples illustrate, the interaction between workers, the equipment, and their environment can actually increase the risk of disastrous errors. Each of these safety hazards ultimately was attributed to a relatively simple, yet overlooked problem with equipment design. The bag of epidural anesthetic was similar in size and shape to IV medication bags, and, crucially, the same catheter could access both types of bags. Full-dose and prophylactic-dose heparin vials appear virtually identical, and both concentrations are routinely stocked in automated dispensers at the point of care. Multiple brands of defibrillators exist that differ in physical appearance as well as functionality; a typical hospital may have many different models scattered around the building, sometimes even on the same unit.

Human factors engineering is the discipline that attempts to identify and address these issues. It is the discipline that takes into account human strengths and limitations in the design of interactive systems that involve people, tools and technology, and work environments to ensure safety, effectiveness, and ease of use. A human factors engineer examines a particular activity in terms of its component tasks, and then assesses the physical demands, skill demands, mental workload, team dynamics, aspects of the work environment (e.g., adequate lighting, limited noise, or other distractions), and device design required to complete the task optimally. In essence, human factors engineering focuses on how systems work in actual practice, with real—and fallible—human beings at the controls, and attempts to design systems that optimize safety and minimize the risk of error in complex environments.

Human factors engineering has long been used to improve safety in many industries outside of health care—it has been employed to analyze errors in aviation, automobiles, and the Three Mile Island nuclear power plant accident. Its application to health care is relatively recent; pioneering studies of human factors in anesthesia were integral to the redesign of anesthesia equipment, significantly reducing the risk of injury or death in the operating room.

Applications of Human Factors Engineering to Improving Safety

The very nature of human factors engineering precludes "one size fits all" solutions, but several tools and techniques are commonly used as human factors approaches to addressing safety issues.

Usability testing—Human factors engineers test new systems and equipment under real-world conditions as much as possible, in order to identify unintended consequences of new technology. One prominent example of the clinical applicability of usability testing involves electronic medical records and computerized provider order entry (CPOE). A seminal study found increased mortality in a pediatric intensive care unit after implementation of a commercial CPOE system, attributable in part to an unnecessarily cumbersome order entry process that reduced clinicians' availability at the bedside. Usability testing might have identified this issue and prompted earlier implementation of solutions—such as standardized order sets and the ability to obtain emergency medications outside of the CPOE system—that subsequently allowed for successful implementation of the system elsewhere. Simulated clinical scenarios may be used to conduct usability testing, as was performed in another study that identified significant limitations of existing CPOE systems. Simulated resuscitation scenarios have also helped identify usability problems with defibrillators.

Usability testing is also essential for identifying workarounds—the consistent bypassing of policies or safety procedures by frontline workers. Workarounds frequently arise because of flawed or poorly designed systems that actually increase the time necessary for workers to complete a task. As a result, frontline personnel work around the system in order to get work done efficiently. In the obstetric example above, the hospital had implemented a bar-code system designed to prevent medication administration errors. However, the system did not reliably scan IV bags. Nurses therefore developed a workaround for urgent situations, whereby they would administer the IV medication without scanning the bar code, and only later manually document its administration. This workaround was deemed to be a substantial contributor to the ultimately fatal error.

Forcing functions—An aspect of a design that prevents an unintended or undesirable action from being performed or allows its performance only if another specific action is performed first. For example, automobiles are now designed so that the driver cannot shift into reverse without first putting his or her foot on the brake pedal. Forcing functions need not involve device design. One of the first forcing functions identified in health care was the removal of concentrated potassium from general hospital wards. This action helps prevent the inadvertent addition of concentrated potassium to intravenous solutions prepared by nurses on the wards, an error that has produced small but consistent numbers of deaths for many years.

Standardization—An axiom of human factors engineering is that equipment and processes should be standardized whenever possible, in order to increase reliability, improve information flow, and minimize cross-training needs. Standardizing equipment across clinical settings (as in the defibrillator example above) is one basic example, but standardized processes are increasingly being implemented as safety measures. The widening use of checklists as a means of ensuring that safety steps are performed in the correct order has its roots in human factors engineering principles.

Resiliency efforts—Given that unexpected events are likely to occur, attention needs to be given to their detection and mitigation before they worsen. Rather than focus on error and design efforts to preclude it, resiliency approaches tap into the dynamic aspects of risk management, exploring how organizations anticipate and adapt to changing conditions and recover from system anomalies. Building on insights from high-reliability organizations, complex adaptive systems, and resourceful providers at the point of care, resilience is viewed as a critical system property, reflecting the organization's capacity to bounce back in the face of continuing pressures and challenges when the margins of safety have become thin.

Despite the above examples, it is generally agreed that human factors principles are underutilized in examination of safety problems and in designing potential solutions. The ever-lengthening list of unintended consequences of CPOE can, in part, be viewed as a failure to appropriately design such systems with human factors in mind.

What's New in Human Factors Engineering on AHRQ PSNet
Examining the Relationship Between Health IT and Ambulatory Care Workflow Redesign.
Zheng K, Ciemins EL, Lanham HJ, Lindberg C. Rockville, MD: Agency for Healthcare Research and Quality; July 2015. AHRQ Publication No. 15-0058-EF.
Lack of standardisation between specialties for human factors content in postgraduate training: an analysis of specialty curricula in the UK.
Greig PR, Higham H, Vaux E. BMJ Qual Saf. 2015;24:558-560.
Preventing Falls With Injury.
Oakbrook Terrace, IL: Joint Commission Center for Transforming Healthcare; August 2015.
An evaluation of the effects of human factors and ergonomics on health care and patient safety practices: a systematic review.
Mao XY, Jia PL, Zhang LH, Zhao PJ, Chen Y, Zhang MM. PLoS One. 2015;10:e0129948.
FDA Drug Safety Communication: FDA warns about prescribing and dispensing errors resulting from brand name confusion with antidepressant Brintellix (vortioxetine) and antiplatelet Brilinta (ticagrelor).
MedWatch Safety Alert. Silver Spring, MD: US Food and Drug Administration; July 30, 2015.
Heparin-containing medical devices and combination products: recommendations for labeling and safety testing. Draft guidance for industry and Food and Drug Administration staff.
Federal Register. Washington, DC: US Department of Health and Human Services. Baltimore, MD: Food and Drug Administration. July 9, 2015;80:39440-39441.
Maximizing smart pump technology to enhance patient safety.
Makic MBF. Clin Nurs Spec. 2015;29:195-197.
Editor's Picks for Human Factors Engineering
From AHRQ WebM&M
The Physical Environment: An Often Unconsidered Patient Safety Tool.
Anjali Joseph, PhD, EDAC; Eileen B. Malone, RN, MSN, MS, EDAC. AHRQ WebM&M [serial online]. October 2012
Workarounds and Resiliency on the Front Lines of Health Care.
Anita L. Tucker, DBA, MS. AHRQ WebM&M [serial online]. August 2009
Vial Mistakes Involving Heparin.
Tim Vanderveen, PharmD, MS. AHRQ WebM&M [serial online]. May 2009
Resuscitation Errors: A Shocking Problem.
Benjamin S. Abella, MD, MPhil; Dana P. Edelson, MD. AHRQ WebM&M [serial online]. July/August 2007
Human Factors Engineering Can Teach You How to Be Surprised Again.
John Gosbee, MD, MS. AHRQ WebM&M [serial online]. November 2006
In Conversation With...Donald A. Norman, PhD.
AHRQ WebM&M [serial online]. November 2006
Thin Air.
David M. Gaba, MD. AHRQ WebM&M [serial online]. October 2004
Patient safety in the cardiac operating room: human factors and teamwork: a scientific statement from the American Heart Association.
Wahr JA, Prager RL, Abernathy JH 3rd, et al; American Heart Association Council on Cardiovascular Surgery and Anesthesia, Council on Cardiovascular and Stroke Nursing, Council on Quality of Care and Outcomes Research. Circulation. 2013;128:1139-1169.
Human factors and ergonomics as a patient safety practice.
Carayon P, Xie A, Kianfar S. BMJ Qual Saf. 2014;23:196-205.
 Classic iconPreventing patient harms through systems of care.
Pronovost PJ, Bo-Linn GW. JAMA. 2012;308:769-770.
 Classic iconA surgical safety checklist to reduce morbidity and mortality in a global population.
Haynes AB, Weiser TG, Berry WR, et al; for the Safe Surgery Saves Lives Study Group. N Engl J Med. 2009;360:491-499.
 Classic iconAn intervention to decrease catheter-related bloodstream infections in the ICU.
Pronovost P, Needham D, Berenholtz S, et al. N Engl J Med. 2006;355:2725-2732.
 Classic iconErgonomic and human factors affecting anesthetic vigilance and monitoring performance in the operating room environment.
Weinger MB, Englund CE. Anesthesiology. 1990;73:995-1021.
 Classic iconPreventable anesthesia mishaps: a study of human factors.
Cooper JB, Newbower RS, Long CD, McPeek B. Anesthesiology. 1978;49:399-406.
 Classic iconThe Checklist Manifesto: How to Get Things Right.
Gawande A. New York, NY: Metropolitan Books; 2009. ISBN: 9780805091748.
 Classic iconManaging the Unexpected: Assuring High Performance in an Age of Complexity, 2nd edition.
Weick KE, Sutcliffe KM. San Francisco, CA: John Wiley & Sons; 2007. ISBN: 9780787996499
 Classic iconThe Design of Everyday Things.
Norman DA. New York, NY: Basic Books; 2002.
 Classic iconSet Phasers on Stun: And Other True Tales of Design, Technology, and Human Error, Second Edition.
Casey SM. Santa Barbara, CA: Aegean Publishing Company; 1998. ISBN 13: 9780963617880.
 Classic iconManaging the Risks of Organizational Accidents.
Reason JT. Aldershot, Hampshire, England: Ashgate; 1997.
 Classic iconHuman Error.
Reason JT. New York, NY: Cambridge University Press; 1990.
Alarm Fatigue in Hospital Setting.
Agency for Healthcare Research and Quality. Health Care Innovations Exchange. June 18, 2014.
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Last Updated: March 2015