Human Factors Engineering and Patient Safety

1
Human Factors Engineering and Patient Safety

• Michigan Health Safety Coalition Annual
  Conference
• John Gosbee, MD, MS
• VA National Center for Patient Safety
• www.patientsafety.gov

2
Introductions

• Mine
• Human factors engineering and healthcare
  specialist
• Adverse events and patient safety
• Curriculum for residents and students
• Invention and innovation
• Yours
• 2 minutes to meet your neighbor
• Your role and why you chose this break-out session

3
Objectives

• Learn about human factors engineering to help
  improve
• Root Cause/Contributing Factors for RCAs
• Failure Modes/Causes for FMEAs
• Begin to understand the scope of HFE is beyond
  devices
• Work areas and entire buildings

4
Human Factors Engineering

• Interaction between human and system
• Dialogue between end-user and their tools
• Tools and concepts to help us with patient safety
• A short quiz to get us started

5
If someone painted all the stop signs in your
town green, which statement is true?

• a.      A few people would notice, but it would
  not increase accidents
• b.      It would have no effect
• c.      It would have a measurable effect with an
  increased accident rate
• d.      A few people who are day-dreaming would
  miss the signs, but not those that cared and
  were paying attention
• e.      Radio warnings and cautions to pay more
  attention would not help

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HFE Quiz (cont.)

• Which blue knob controls the dial on the right?
  Why?

Control Panel
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Human Factors Model

• Psychomotor
• Hand
• - Feet

• Input Devices
• Buttons
• - Foot pedal

INTERFACE
Senses - Vision - Hearing
Output - Color display - Sound
8
Radar Scope to Detect enemy ships
9
ECG Signal (Telemetry) Monitoring
10
Performance Graph (curve)
100
90
80
70
Performance
1
2
3
4
Time (hours)
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Performance Graph (curve)
100
90
80
70
Performance
1
2
3
4
Time (hours)
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How can we move the curve upwards?
100
90
80
70
Performance
1
2
3
4
Time (hours)
13
Another Demonstration with a Patient Safety Twist

• Look at the next slide
• Count the number of words in the paragraph that
  are repeated

14
Medical Device Correlation

• What does this phrase mean ? Telemetry Off
• To a novice? To an expert?

15
What is this regulator used for?

• Write your answer down on paper

16
Demonstration Stroop Test
Row 1
Row 2
Row 3
17
Sources Medical Mistake Left Newborn In
Coma KITV-TV HONOLULU - A medical mistake at
Tripler Army Medical Center has left a newborn
baby in a coma with severe brain damage. Sources
familiar with this case tell KITV 4 News that
Tripler officials apologized to the family of a
baby boy born there in January after he was
mistakenly given carbon dioxide right after
birth, instead of oxygen. The baby boy was born
Jan. 14 at Tripler Army Medical Center during a
scheduled cesarean section delivery, sources told
KITV 4 News. They said medical personnel
mistakenly gave him carbon dioxide immediately
after birth instead of oxygen. Sources said the
operating room may have been set up incorrectly.
18
Volunteer to Write Instructions

• Starting from Peanut Butter Jar and Bag of Bread
• Ending with - peanut butter sandwich (two slices
  of bread) on the plate

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The Normalization of Complexity

• Healthcare workers compensate for complex,
  unclear workplaces and devices
• IV Pumps, for example
• Unclear or absent information or cues to
  understand how to accomplish desired goal
• Mastery of the complex becomes a normal strategy,
  without regard to reasonableness or necessity of
  complexity

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Broad Impact of Human Factors Engineering

• Aviation (since 1940s)
• Nuclear Power
• Space flight
• Computer software and hardware (Xerox PARC 1970s)
• Consumer products (Palm Pilot, Snakelight)
• Railroad, motor vehicle, farm machinery, etc.

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Human Factors Engineering and Your World

• Anesthesiology
• Design of alarms, monitors, and safety systems
• Emergency Medicine
• Design of decision-making tools and monitoring
• Surgery
• Design of hand tools and visualization devices
  (laparoscopy)

22
Healthcare SystemsRange from the Simple to
Complex

• Syringe, catheter bag and its tubing
• O2 cylinder, ECG machine, IV pump
• Code cart, anesthesia work station
• Hospital computer system
• MRI control room and suite
• ICU, ED, OR

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Human Factors Engineering is about the whole
system

• Whats the design of the training and education
• Labeling and instructions attached to device
• Policy and procedures?
• Information displays
• Pieces of paper
• Layout and structure of the room, layout of the
  floor, layout of the facility, overall environment

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Design and Test of Written Documents

• Policies and procedures
• Steps to use a device
• Instructions or help screen for software
• It seems easy, but
• Peanut butter sandwich making demo as an example

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HFE and Patient Safety Lesson

• Simple steps never are
• Learned intuition and assumptions
• Stereotypes
• Metaphors
• Iterative testing of instructions to work the
  bugs out

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Learned intuition examples

• Secretaries using computers
• Other examples?

27
Human factors engineering and patient safety case
studies

• Code Cart drawer
• PCA pump

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Baseline Drawer (Laundry hamper)Range
243-358 min, Avg307 min
Note the multiple orientations
29
Code Cart Drawer Fifth Version Range 55-125
min, Avg108
Note the lack of labels for each spot
30
PCA Interface Redesign Univ. Toronto
Existing Design
New Design
31
PCA Programming Sequence Redesign
Existing Design
New Design
32
Usability Evaluation of a PCA Pump Measurements

• Programming Errors Measured
• Quantity
• Severity
• Performance Measured
• Programming Time
• Task completion time
• Mental Workload Ratings ? NASA-TLX

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PCA Pump Errors - Results

• New Interface
• 55 reduction in number of errors
• Zero errors in entering drug concentration
• Old interface
• 8 drug concentration errors were made
• 3 of these were not detected and were left
  uncorrected
• Mode Errors
• Old interface errors involved selecting the wrong
  mode (11 errors, 9 of which were eventually
  corrected
• With the new interface, only 3 such mode
  selection errors occurred, all of which were
  eventually corrected

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Other Results

• Task Completion Time
• 11/12 end-users faster with new interface
• Average 18 faster
• No difference in Subjective Workload
• Over 90 preference for new interface

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How can we APPLY all of this theory?

• Set of principles
• If they are not followed, adverse events always
  will
• Set of guidelines
• If they are ignored, again, adverse events will
  occur
• We will present a short list of guidelines now

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Human Factors Engineering Guidelines
(Adapted from Nielsen, 1992)

• 1. Simple and Natural Dialogue
• 2. Speak the Users Language
• 3. Minimizing User Memory Load
• 4 . Consistency
• 5. Feedback
• 6. Clearly Marked Exits
• 7. Prevent Errors
• Good Error Messages
• Help and Documentation
• Readable and understandable labels and warnings

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Simple and Natural Dialogue

• Dialogue is between the user of a device and the
  device
• The device communicates to the person with
• Physical shape, feel
• Labeling including symbols and words
• Characteristics of parts that connect to other
  devices or a person
• Environment can affect this dialog in the way
  that background noise makes hearing difficult

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Prerequisites for simple natural dialogue

• How a device/process/workplace is designed needs
  to fit with the work done (fit glove to the hand)
  and the person doing it
• Because how specific users do their specific jobs
  gives you
• Insight into their mental model
• Understanding mismatch between the person and the
  system design

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Take a look around us
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Clinical Example Radioactivity Calculator
Software

• Used to determine radioactivity of the pellet
  to be placed near the patients tumor
• This determines how long to leave it there during
  surgery
• Key data is the date field XX/XX/XX
• What date is 01/12/99?

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Consistency

• Controls that look the same act the same
• Displays or terms that look the same act the same
• Overall
• Refer to one item with the same name all the time
• Conversely, refer to different items with
  distinct names

42
Consistency

• Location of controls
• Typewriter
• Brake pedal in car
• Defibrillator

43
Consistency Examples from daily life
44
Consistency Clinical Example

• Your Examples? testimonials

45
Feedback

• Users want to know what is happening in terms
  they understand
• Device or system should indicate current status
  of the system
• Examples of feedback from your computer
• Beep when you do certain bad things
• Thermometer or hourglass display to indicate
  progress in task

46
Real world examples
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Clinical Example Defibrillator
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Feedback your examples
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Readable and understandable labels and warnings

• Seemingly easy to doits not
• Thousands of examples, including our own earlier
• Caused by
• Jargon
• Complexity of most design processes
• Unneeded creativity

50
Clinical Example 1 Cardiac Monitor
This piece of tape says On/Off
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Clinical Example 2 Syringe
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Clinical Example Syringe

• Syringe labeling on plunger, not syringe itself
• Harder to read with liquid in the syringe
• Not usual measuring cup model of figuring out
  volume in syringe

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Your clinical examples
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Conclusions and Next Steps

• HFE contains concepts that underlie patient
  safety
• Small group exercises
• Principles applied to many systems
• Usability testing method revealed!
• More resources follow this slide

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AdvaMed Infusion Pump Working Group

• Usability Objectives for all future IV pumps
• Feeding off FDA and ANSO/AAMI 74 guidance
• Examples
• 90 min-trained users can turn on pump in 20 sec
• 85 min-trained can program basics in 5 min

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HFE Web Resources

• Wiklund M. Eleven Keys to Designing
  Error-Resistant Medical Devices. MDDI. May
  2002 pp. 86-90. http//www.devicelink.com/mddi/ar
  chive/02/05/004.html
• VA Web Site http//www.patientsafety.gov/hf.html
  
• FDA Web Site and Publications (free and good!)
• http//www.fda.gov/cdrh/humanfactors/
• Human Factors Engineering and Medical Devices
  (Do It By Design Device Use Safety)

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Web Sites (more)

• Human Factors Society (HFES)
• Website http//www.hfes.org/
• Graduate programs in Human Factors
• Local Chapters of the Human Factors Society
• The Usability Professionals Association (UPA)
• Website http//www.upassoc.org/index.html
• Local Chapters of the Usability Prof Association
• ACM-Special Interest Group on Computer-Human
  Interaction (SIGCHI)
• Website http//sigchi.org/
• Local Chapters of SIGCHI

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Academia

• University of Wisconsin
• Series of courses for masters in HFE and patient
  safety
• Students from nursing, medicine, engineering
• HFE and BME key to research agenda
• http//www.engr.wisc.edu/ie/
• University of Maryland
• Video analysis in OR and ED
• Alarms redesign
• HFE and BME key to DCERPS
• http//www.safetycenter.umm.edu/

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Academia (cont.)

• University of Virginia
• Laparscopic Cholecystectomy training, etc.
• http//www.sys.virginia.edu/hci/
• University of Toronto
• PCA pumps
• Procurement
• Savings from one device investigation paid for
  expense of HF Expert for one year
• http//www.mie.utoronto.ca/labs/cel/research/pca.h
  tml
• http//www.mie.utoronto.ca/labs/cel/

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Bibliography

• Gosbee JW. Introduction to the human factors
  engineering series. Joint Commission Journal on
  Quality and Safety. 2004 30(4) 215-219.
• Gosbee JW, Anderson T. Human factors engineering
  design demonstrations can enlighten your RCA
  team. Quality Safety in Health Care. 2003
  12 119-121. http//qhc.bmjjournals.com/cgi/conten
  t/abstract/12/2/119?etoc
• Dumas, J. and Redish, G. (1993). A Practical
  Guide to Usability Testing. Norwood, NJ Ablex.
• Nielsen, J. (1993) Usability Engineering.
  Boston AP Professional.
• Rubin, J. (1994). Handbook of Usability Testing.
  New York John Wiley Sons, Inc.