1. Usability and Human Factors
Unit 4: Human Factors and Healthcare
Welcome to Usability and Human Factors, Human Factors and Healthcare. This is Lecture a.
This lecture provides an introduction to the discipline of human factors with a particular focus on human factors concepts and principles. We will also characterize the ways in which human factors analysis makes use of concepts from applied cognitive psychology. We will particularly focus on the issue of selective and divided attention. The subsequent section of this unit focuses on patient safety issues and concepts as well as an introduction to the analysis of human error. The focus is on understanding the nature of human error and appreciating a systems-centered approach, which emphasizes the multiplicity and complexity of causes of human error. We then turn our attention to workload, which is an important construct pertaining to the potential for error in a work setting. In the final section of this unit, we will examine medical devices and discuss two human factor studies that examine efficacy of such devices in clinical and home-health contexts.
Lecture a
This material (Comp 15 Unit 4) was developed by Columbia University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information Technology under Award Number 1U24OC This material was updated by The University of Texas Health Science Center at Houston under Award Number 90WT0006.
This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. To view a copy of this license, visit

2. Human Factors and Healthcare Lecture a – Learning Objectives
Objective 1: Distinguish between human factors and human computer interactions (HCI) as they apply to usability (Lecture a)
Objective 2: Explain how cognitive, physical and organization ergonomics can be applied to human factors engineering (Lecture a)
Objective 3: Describe how the concepts of mental workload, selective attention and information overload affect usability (Lecture a)
Objective 4: Describe the different dimensions of the concept of human error (Lecture b)
The objectives for this unit, Human Factors and Healthcare, Lecture a are to: 1) Distinguish between human factors and human computer interactions (HCI) as they apply to usability
2) Explain how cognitive, physical and organization ergonomics can be applied to human factors engineering and
3) Describe how the concepts of mental workload, selective attention and information overload affect usability

3. Human Factors and Healthcare Lecture a – Learning Objectives (Cont’d – 1)
Objective 5: Describe a systems-centered approach to error and patient safety (Lecture b)
Objective 6: Apply methods for measuring mental workload and information overload (Lecture c)
Objective 7: Describe how human factors analysis can be applied to the study of medical devices (Lecture c)
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4. Electronic Health Devices & Health Record Systems
Human factors is a discipline devoted to the study of technological systems and how people work with them or are affected by them. It is concerned with the full range of health-related technologies and systems used by a diverse range of people including clinicians, hospital administrators, health consumers and patients.
Image 1.1: Patel, V. L., Kaufman, D., & Kubose T. (2002)
Image 1.4: Kaufman, D. R., Pevzner, J., Rodriguez, M., et al. (2009).
Image 1.2: Kaufman, D.R. & Starren, J. B. (2006).
Image 1.5: Kaufman, D.R., Patel, V.L., Hilliman, C., et. Al. (2003).
Image 1.3: Kaufman, D.R., Pevzner, J, Hilliman, C., et. Al. (2006).
Image 1.6: Kaufman, D., & Hripcsak, G. (2008).
Image 1.4: Horsky, J., Kaufman, D.R., Oppenheim, M.I. & Patel, V.L. (2003).

5. Human Factors and HCI Redux
Differences:
Histories, journals, academic and professional societies
HCI focused on computing and innovative design
HF focused on any system and greater emphasis on work/workplace and on devices
Safety is a core issue in HF
In this lecture, we will frequently talk about both human factors and human computer interaction (HCI). They are different disciplines with different histories and separate professional and academic societies. HCI is more focused on computing and cutting-edge design and technology. Human Factors (HF) focus on a range of systems that covers a wider range of hospital and other technologies. Patient safety is one of the central issues in human factors research.
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6. Human Factors and HCI Redux (Cont’d – 1)
Similarities
User-centered and systems approach
Draws on cognitive psychology and other social sciences
Similar methods with regards to usability evaluation
Cognitive task analysis
Usability testing
However, the two domains employ many of the same methods of evaluation and both strongly emphasize a user-centered approach to design and a systems-centered approach to the study of technology use. Researchers and professionals in both domains draw on the same set of theories including cognitive engineering.
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7. History of Human Factors:
Industrial efforts to increase worker productivity
1945 – 1960:
Formal beginning of the profession – military
1960 – 1980:
Rapid growth and expansion – space program, product design, workplace design
This slide covers the history of human factors from the earliest efforts of engineers to increase the productivity of factory workers by changing environmental conditions. The discipline became formalized towards the end of World War II and shortly thereafter began an age of great expansion. This time corresponded to the beginning of the space age and the rapid growth of the automobile industry as well as aviation.

8. History of Human Factors (Cont’d – 1)
1980 – 1990:
Human computer interaction, safety/human error
1990 – Present expansion
e.g., healthcare, aging, aviation safety, standardization
The last years have witnessed a considerable growth of the discipline in scope and importance. Health care has also become a focal point of work in Human Factors.

9. Why is Human Factors Increasingly Important
Diversity of user groups
Complexity of systems
Increased use of technology
Increased “costs” of human error
Societal emphasis on well-being and quality of life
Human factors have grown in importance and in public awareness in recent decades. Some of this is due to an increase in the use of technology by a diverse population of users (most of whom are not experts), a growing awareness of safety, and the cost of error. In industry, there is an increasing recognition of the need for better quality control and the fact that it conveys a competitive edge. The car industry is a case in point. There is a general perception that Japanese and European cars are of greater quality and this has hurt the sales of North American cars.

10. Human Factors Focus and Goals
Human beings and their interactions with products/equipment, tasks, environments
Micro, macro, ambient
Goal
Design systems and system components to match the capabilities and limitations of humans who use them
Optimize working & living conditions
What is the central focus of HF work? Broadly, it is people and their interaction with the gamut of technologies and systems. This interaction can occur at different levels. The micro level, is, according to Bubb (2012), is “more engineering oriented” and ”gives rules for the technical design of workplaces and working means. In contrast, Bubb defines “macro ergonomics”, as providing “rules for the creation of organization, company groups and study groups.”
The goal of this work is to optimize these technologies such that they match the capabilities and limitations of people who use them. As we will discuss, cognitive psychology plays a very important role in human factors analysis.
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11. Examples of Application Areas
Military
Highway systems
e.g. readability and comprehensibility of signs
Automobile design and driver behavior
Human-computer systems
Healthcare and patient safety
Aging and accessibility
Nuclear power
Workplace layout and furnishings
Airline industry
e.g. pilot workload, aircraft design, automation, aircraft maintenance
Quality control
These are just some examples of application areas in human factors. We will focus on computer systems and patient safety, but we will also touch on other areas of interest that exemplify important concepts and principles.

12. Nuclear Power Plant Control Room
Here is a picture of a control room in a nuclear power plant. Safety is a crucial issue in these settings. The television cartoon character Homer Simpson is probably not the embodiment of the ideal nuclear power safety inspector, although he is the best known. The picture illustrates the immense complexity of such an environment and one can imagine the demands on human operators. There have been several significant accidents in such plants and they have served as excellent case studies in human factors engineering.
Lambrev, Y. (2009).

13. Airplane Cockpit Headly, A. (2005). CC BY NC-SA 4.0.
The aviation industry is one of the first to embrace the discipline of human factors as well as human factors engineering principles. Although airplane crashes make the front pages of our newspapers when they happen, the airline industry has an excellent safety record in recent decades. Much work has been done on airplane cockpit displays (see work done by Christopher Wickens) and airlines have evolved a rather elaborate set of procedures for ensuring safe practices, which includes rigorous training of pilots and ensuring maintenance of pilot’s competencies. We hear about the failures in aviation, but on balance they set a high standard for matters of safety.
In the last decade or so, the health care sector has to some extent patterned itself after the aviation industry. For example, checklists, structured communication techniques, error reporting and simulator training are some of ways in which the healthcare sector has endeavored to adopt the safety practices and methods of the aviation industry.
Headly, A. (2005). CC BY NC-SA 4.0.

14. Human Factors in Medicine
Infusion pumps
Anesthesia equipment
Medication errors
Effects of fatigue on resident’s performance
Judgmental limitations in medical decision making
Inadequate infection control
Unintended consequences of automation
These are some examples of applications of human factors work in medicine. Infusion pumps are used to infuse fluid and medications into patient’s circulatory system. In recent years, there have been growing concerns about the safety of these devices. Over one million patients are injured annually by medication errors. Although most are relatively minor, some result in serious patient harm and even fatalities. The effects of fatigue, night shift work, and sleep deprivation on human performance and the safety of medical care are subjects of enormous interest within the medical community. Although this remains a controversial issue, several states have mandated that medical residents limit the number of consecutive hours in a given shift. Infection control continues to be a serious problem in hospitals. Simple intervention like the close scrutiny of hand-washing behavior of clinicians has had a significant impact on controlling infection rates in hospitals. All technology has unintended consequences ranging from positive to highly detrimental to patient safety.
We will return to the issue of patient safety and discuss some of these examples after we review some of the core concepts and central issues in human factors.

15. Human Factors/Ergonomics (Carayon, 2007)
Scientific discipline concerned with understanding interactions
Among humans
Other elements of a system
Profession that applies theory, principles, data, methods to design to optimize:
human well-being
overall system performance
System can be a technology, device, person, team, organization, policy, etc.
As we discussed previously, human factors is a profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance. Unlike HCI, a system does not merely refer to a computing system. It may be a device, person, team, organization, or policy, to name a few.

16. Human Factors Ergonomics: 3 Major Domains
Physical Ergonomics
Cognitive Ergonomics
Organizational / Macro-ergonomics
Ergonomics is broadly conceived as the study of work and factors that affect it. The term is sometimes used interchangeably with human factors. In any case, we can characterize 3 major domains: physical ergonomics, cognitive ergonomics, and organizational or macro-ergonomics. Let’s look at each of these now.
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17. Physical Ergonomics Concerned with physical activity:
Topics: Repetitive movements, workplace layout, safety and health
Application to Health: Reducing and preventing injury, designing workstations and work rooms for optimal human performance
Examples:
Designing a patient room to facilitate and support patient care
Designing medical labels so that they are readable and understandable
Physical Ergonomics is concerned with physical activity and covers a wide range of related issues including understanding and reducing injuries in the workplace (such as repetitive stress injury). In the health care domain, this could include reducing and preventing injury and designing workstations and workrooms for optimal human performance. An example would be designing medication labels so that they are readable and understandable.
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18. Organizational Ergonomics
Concerned with socio-technical systems
Topics: communication, teamwork, participatory design, quality management
Application to Health: Reducing stress and burnout, improving satisfaction and retention, implementing improvement activities
Examples:
Management training in surgery teams
Designing work schedules for reduced fatigue and enhanced performance
Organizational Ergonomics is concerned with the study of socio-technical systems. The topics in this area include communication, teamwork, participatory design, and quality management. An example of an application to health is taking steps to reduce stress and employee burnout. Redesigning work schedules is one way to try and diminish the risk of burnout.
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19. Cognitive Ergonomics Concerned with mental processes
Topics: mental workload, decision making, skilled performance, HCI, work stress,
Application to Health: usability, designing training systems, usable interfaces
Examples:
Event report systems
Implementing incident analysis system
Recall that cognition, as defined by the Merriam-Webster dictionary, is “conscious mental activities: the activities of thinking, understanding, learning, and remembering”. So, Cognitive Ergonomics addresses the gamut of cognitive issues including decision making, skilled performance, and mental workload, which is an issue that we will come back to later in this lecture. It also addresses usability of systems, which is a central issue in this course. This lecture focuses predominantly on cognitive issues.
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20. Human Factors & Applied Cognitive Psychology
Applies knowledge about human strengths and limitations to design of interactive systems, equipment, and their environment to ensure their effectiveness, safety, and ease of use
Perception, attention, memory, mental models and decision making are central to human factors research and analysis
Human factors can be construed as a discipline guided by principles of engineering and applied cognitive psychology. Human factors analysis applies knowledge about the strengths and limitations of humans to design interactive systems, equipment, and their environment. The objective is to ensure their effectiveness, safety, and ease of use. Mental models and issues of decision making are central to human factors analysis. Any system will be easier and less burdensome to use to the extent that that it is co-extensive with users’ mental models.
We will now focus on matters of attention, which is also a central concern in human factors analysis.

21. Human Attention Selective Mechanism
Resource needed for information processing
Limited
Sharable
Flexible
Human factors focus on different dimensions of cognitive capacity, including memory, attention, and workload. Our perceptual system inundates us with more stimuli than the cognitive system can possibly process. Attention mechanisms enable us to selectively prioritize and attend to certain stimuli and attenuate other ones. Attentional resources are limited. They also have the property of being sharable which enables us to multitask by dividing our attention between two activities. If we are driving on a highway, we can easily have a conversation with a passenger at the same time. However, as the skies get dark or the weather changes or suddenly you find yourself driving through winding mountainous roads, you will have to allocate more of your attentional resources to driving and less to the conversation.
Most states have outlawed the use of handheld cell phones while driving, because they serve to divide one’s attentional resources and greatly increase the likelihood of accidents and highway fatalities. On the basis of studies thus far, it is not clear that using a hands free cell phone has any effect on reducing driving accidents. It has the effect of sapping one’s needed attentional resources.
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22. Selective Attention
Ability to ignore extraneous information and focus on relevant inputs
Information overload contributes to errors
We have the ability to ignore extraneous information and focus on relevant information. However, humans can only process information at a finite rate, and performance typically declines as the number of sources of information increases. Information overload is a common cause of performance errors.

23. Information Overload Speed Stress Load Stress
Speed / Accuracy Tradeoff
This slide describes some of the conditions for overload. If you are under pressure to increase the pace of your performance or if you are burdened by a heavy information load, the quality or accuracy of performance is likely to degrade. There is a speed/accuracy tradeoff. As you increase your speed of performance, beyond a certain threshold, you increase the probability that the quality or accuracy of your work will degrade.
Think of physicians and nurses in an emergency department. They may be working with several critical patients at the same time, which is a high-stress situation often demanding rapid action. In addition, this is an environment with a high rate of interruptions. These factors could contribute to errors.
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24. Selective Attention (Cont’d – 1)
Four factors drive the selection of channels to attend (and the filtering of channels to ignore):
Salience:
Events or stimuli that are salient capture attention (this represents a bottom-up process)
Expectancy and Value:
We tend to “sample” the world where we expect to find information, and attend to channels based on how valuable it is to look or costly to miss
Effort:
Selective attention may be inhibited if it is effortful
This slide lists four factors that drive the selection of channels to attend to (in other words, to pay attention to).
First, events or stimuli that are salient tend to capture our attention. For example, loud music, or a conversation where someone mentions your name, is likely to capture your attention.
Second, we tend to sample the world where we expect to find information, and third, we attend to channels based on how valuable it is to look or costly to miss. This can be a property of expertise. Nuclear power plant operators or intensive care nurses are trained to attend to particular signals, which are vitally important.
Finally, if we are inundated with stimuli, such efforts may be fruitless. For example, trying to study complex subject materials in a noisy café may be very effortful – in other words, difficult. On the other hand, we may be able to read a newspaper or a novel in the same environment – less effort is required.

25. Divided Attention or Time Sharing
Ability to perform more than one cognitive task by attending to both at once or rapidly switching back and forth between them
Because cognitive resources for attention are relatively limited, time-sharing often results in a drop in performance for one or both tasks
People can also “modulate” the resources given to one task or the other
Time-sharing refers to the ability to perform more than one cognitive task by attending to both at once or rapidly switching back and forth between them. We do that routinely divide our attention when working on our computer. We may be writing, listening to music and watching out for an important or text message. However, given the fact that cognitive resources for attention are relatively limited, time-sharing often results in a drop in performance for one or both tasks. We can modulate our attention resources by giving more attention to the task that is more important at the moment.

26. Human Factors Design Implications
Reduce the number of competing channels of information
Make sources of information as distinct as possible
Provide feedback
Use redundant cues
Work/rest scheduling
Training
On the basis of human factors research, we can draw the following design implications.
If possible, reduce the number of channels that one needs to attend to.
Make sources of information as distinct as possible. For example, an intensive care nurse may hear 10 or 12 different kinds of alarms that signal various kinds of patient needs or concerns. However, the sounds are sufficiently distinct that he or she will know which ones warrant immediate attention and which ones can wait a little longer.
Electronic health records can be designed (or templates developed) that correspond better to the desired clinician workflow and displays can be structured to provide easier access to needed information.
Work scheduling can be used to reduce fatigue and improve performance.
Although training is not a substitute for poor design, it can provide workers with strategies and resources to work more productively within the limitations of a given system.

27. Unit 4: Human Factors and Healthcare Summary – Lecture a
Growing importance of human factors in health and other domains
Domains of human factors
Applied cognitive psychology and human performance
Human attention, performance and design implications
Next section: Patient safety and human error
This conclude Lecture a of Unit 4: Human Factors and Healthcare.
In summary, we considered the growing importance of human factors in health and other domains, briefly considered different domains of human factors and ergonomics. Applied cognitive psychology provides some of the theoretical basis for understanding human performance in the context of human factors. The lecture also considered the issue of attention and the important role it plays in modulating performance in the work place. In the next section, we consider the issue of patient safety and models of error.

28. Unit 4: Human Factors and Healthcare References – Lecture a
Bubb, H. Information Ergonomics. In Herczeg, M., & Stein, M., eds. (2012). Information Ergonomics: A theoretical approach and practical experience in transportation. Springer Berlin Heidelberg, p. 23.
Images
Slide 4:
Image 1.2: Kaufman, D.R. & Starren, J. B. (2006). A methodological framework for evaluating mobile health devices. In the Proceedings of the American Medical Informatics Annual Fall Symposium. Philadelphia: Hanley & Belfus. 978
Image 1.3: Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., Teresi, J. Shea, S. & Starren, J. (2006). Re-designing a telehealth diabetes management program for a digital divide seniors population. Home, Healthcare, Management & Practice. 18:
Image 1.1: Patel, V. L., Kaufman, D., & Kubose T. (2002). Infusion Pump—unpublished work
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29. Unit 4: Human Factors and Healthcare References – Lecture a (Cont’d – 1)
Images
Slide 4:
Image 1.4: Kaufman, D. R., Pevzner, J., Rodriguez, M., Cimino, J. J., Ebner, S., Fields, L., et al. (2009). Understanding workflow in telehealth video visits: Observations from the IDEATel project. Journal of Biomedical Informatics, 42(4),
Image 1.4: Horsky, J., Kaufman, D.R., Oppenheim, M.I. & Patel, V.L. (2003). A framework for analyzing the cognitive complexity of computer-assisted clinical ordering. Journal of Biomedical Informatics, 36, 4-22.
Image 1.5: Kaufman, D.R., Patel, V.L., Hilliman, C., Morin, P.C., Pevzner, J, Weinstock, Goland, R. Shea, S. & Starren, J. (2003). Usability in the real world: Assessing medical information technologies in patients’ homes. Journal of Biomedical Informatics, 36,
Image 1.6: Kaufman, D., & Hripcsak, G. (2008). eClinicalWorks screen. Unpublished usability analysis of eClinicalWorks.
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30. Unit 4: Human Factors and Healthcare References – Lecture a a (Cont’d – 2)
Images
Slide 12: Lambrev, Yovko. (2009). Kozloduy nuclear plantc- control room. Retreived on August 20th, 2010 from [CC-BY-3.0 ( via Wikimedia Commons
Slide 13: Headly, Aaron. (2005). Retrieved on September 10th, 2010 from
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31. Unit 4: Human Factors and Healthcare Lecture a
This material was developed by Columbia University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information Technology under Award Number 1U24OC This material was updated by The University of Texas Health Science Center at Houston under Award Number 90WT0006.
No Audio.
Health IT Workforce Curriculum Version 4.0