1 Human Factors Engineering and Patient Safety Michigan Health & Safety Coalition – Annual...

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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

PSIC - January 2004 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


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


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


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 accidentsb. It would have no effectc. It would have a measurable effect with an increased accident rated. A few people who are day-dreaming would miss the signs, but not

those that cared and were paying attentione. Radio warnings and cautions to pay more attention would not help


HFE Quiz (cont.)

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

Control Panel


Human Factors Model

Senses- Vision - Hearing

Psychomotor- Hand

- Feet

Input Devices- Buttons

- Foot pedal

Output- Color display - Sound

INTERFACE


Radar Scope to Detect “enemy” ships


ECG Signal (Telemetry) Monitoring


100%

90%

80%

70%

Time (hours)1 2 3 4

Perf

orm

an

ce

Performance Graph (curve)


How can we move the curve upwards?

100%

90%

80%

70%

Time (hours)1 2 3 4

Perf

orm

an

ce


Another Demonstration with a Patient Safety Twist

Look at the next slide

Count the number of words in the paragraph that are repeated


Medical Device Correlation

What does this phrase mean “Telemetry Off”

To a novice? To an expert?


What is this regulator used for?

Write your answer down on paper


Demonstration: Stroop Test

Row 1

Row 2

Row 3


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.


Volunteer to Write Instructions

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


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


Broad Impact of Human Factors Engineering

Aviation (since 1940’s)Nuclear PowerSpace flightComputer software and hardware (Xerox PARC 1970s)Consumer products (Palm Pilot, Snakelight)Railroad, motor vehicle, farm machinery, etc.


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)


Healthcare “Systems”Range 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


Human Factors Engineering is about the whole system

What’s the design of the training and educationLabeling and instructions attached to devicePolicy and procedures?Information displays– Pieces of paper

Layout and structure of the room, layout of the floor, layout of the facility, overall environment


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


HFE and Patient Safety Lesson

Simple steps never areLearned intuition and assumptions– Stereotypes– Metaphors

Iterative testing of instructions to work the bugs out


Learned intuition examples

Secretaries using computersOther examples?


Human factors engineering and patient safety case studies

Code Cart drawerPCA pump


Baseline Drawer (“Laundry hamper”)Range = 2:43-3:58 min, Avg=3:07 min

Note the multiple orientations


Code Cart Drawer Fifth Version Range = :55-1:25 min, Avg=1:08

Note the lack of labels for each spot


PCA: Interface Redesign – Univ. Toronto

Existing Design New Design


PCA: Programming Sequence Redesign

Existing Design New Design

DecisionMessage-guided ActionAction

Legend


Usability Evaluation of a PCA Pump: Measurements

Programming Errors Measured– Quantity– Severity

Performance Measured– Programming Time– Task completion time

Mental Workload Ratings NASA-TLX


PCA Pump Errors - ResultsNew 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


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


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


Human Factors Engineering Guidelines (Adapted from Nielsen, 1992)

1. Simple and Natural Dialogue

2. Speak the Users’ Language3. Minimizing User Memory Load4 . Consistency 5. Feedback

6. Clearly Marked “Exits”7. Prevent Errors8. Good Error Messages9. Help and Documentation 10. Readable and understandable labels and warnings


Simple and Natural Dialogue

Dialogue is between the user of a device and the deviceThe 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


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 itBecause how specific users do their specific jobs gives you– Insight into their “mental model”– Understanding mismatch between the person and

the system design


Take a look around us


Clinical Example – Radioactivity Calculator Software

Used to determine radioactivity of the “pellet” to be placed near the patient’s tumorThis determines how long to leave it there during surgeryKey data is the date field XX/XX/XXWhat date is 01/12/99?


Consistency

Controls that look the same act the sameDisplays or terms that look the same act the sameOverall– Refer to one item with the same name all the time– Conversely, refer to different items with distinct

names


Consistency

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


Consistency: Examples from daily life


Consistency: Clinical Example

Your Examples? – testimonials


Feedback

Users want to know what is happening in terms they understandDevice or system should indicate current status of the systemExamples of feedback from your computer– “Beep” when you do certain “bad” things– “Thermometer” or “hourglass” display to indicate

progress in task


Real world examples


Clinical Example – Defibrillator


Feedback – your examples


Readable and understandable labels and warnings

Seemingly easy to do…it’s notThousands of examples, including our own earlierCaused by– Jargon– Complexity of most design processes– Unneeded creativity


Clinical Example #1 – Cardiac Monitor

This piece of tape

says “On/Off”


Clinical Example #2 – Syringe


Clinical Example – Syringe

Syringe labeling on plunger, not syringe itselfHarder to read with liquid in the syringeNot usual “measuring cup” model of figuring out volume in syringe


Your clinical examples


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


AdvaMed Infusion Pump Working Group

Usability Objectives for all future IV pumpsFeeding off FDA and ANSO/AAMI 74 guidanceExamples– 90% min-trained users can turn on pump in 20 sec– 85% min-trained can program basics in 5 min


HFE Web Resources

Wiklund M. Eleven Keys to Designing Error-Resistant Medical Devices. MD&DI. May 2002 pp. 86-90. http://www.devicelink.com/mddi/archive/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”)


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


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/


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.html– http://www.mie.utoronto.ca/labs/cel/


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/content/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.

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