understanding variation in healthcare

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Understanding Variation In Healthcare

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Understanding Variation In Healthcare. W. Edwards Deming. “If I had to reduce my message to management to just a few words, I’d say it all has to do with reducing unnecessary variation.”. Numbers We Use Every Day. Time taken to drive to work Number of patients in the ED - PowerPoint PPT Presentation

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Page 1: Understanding Variation In Healthcare

Understanding Variation

In Healthcare

Page 2: Understanding Variation In Healthcare

W. Edwards Deming

“If I had to reduce my message to management to

just a few words, I’d say it all has to do with reducing unnecessary variation.”

Page 3: Understanding Variation In Healthcare

Numbers We Use Every Day

• Time taken to drive to work• Number of patients in the ED• Number of medication errors• Revenue per month• Average daily census in the

hospital• Number of research studies

approved by the IRB per week.

Page 4: Understanding Variation In Healthcare

How to look at data

Page 5: Understanding Variation In Healthcare

Registration Times• Actual time (minutes) it took to

register patients in a hospital ED15 67 4 14 10

12 54 3 7 11

14 83 54 17 20

10 53 What information do these numbers provide?

Page 6: Understanding Variation In Healthcare

Does this help?

22.4

29.6

0

5

10

15

20

25

30

Min

utes

Monday Tuesday

Page 7: Understanding Variation In Healthcare

Does this help?• Average waiting time is…….• The mode (frequent number) is……• The median is…………..

Would any of these numbers help improve the process?

Page 8: Understanding Variation In Healthcare

Run Chart of ED Registration Time

0102030405060708090

100

Patient Number

Min

utes

to R

egis

ter

MEAN

Page 9: Understanding Variation In Healthcare

Run Chart• May not give you all the answers, but

it well help you ask smarter questions (e.g. What happened when the registration time was much higher?)

• Provides insight into process behavior (Seems like there are two processes, one group registers quickly the other more slowly.)

• No statistical calculations needed

• Use for any type of process and any type of data

Page 10: Understanding Variation In Healthcare

Understanding Variation• Variation exists and permeates

all processes. No two things are exactly alike. The problem we face is to be able to measure the extent of the variation and to establish to what degree the variation matters and to whom it matters.

Page 11: Understanding Variation In Healthcare

Common and Special Cause Variation

Write the letter “a” eight times on a piece of paper using your

dominant hand. Make all of them the same.___ ___ ___ ___ ___ ___ ___ ___

Are they exactly the same? Why or why not?

Page 12: Understanding Variation In Healthcare

Common and Special Cause Variation

Write the letter “a” three times using your dominant hand, three times with

your other hand, then two times with your dominant hand.

Make all of them the same.

___ ___ ___ ___ ___ ___ ___ ___

Are they the same? Why or why not?

Page 13: Understanding Variation In Healthcare

• The dominant hand created variation because of the pen and/or paper you used, amount of coffee you’ve had, friction of your hand, etc. etc. This is common cause variation. It is inherent in the process.

• Using the non-dominant hand clearly shows something very different. This is special cause—it does not always happen in the process of writing. Since it so different, you would want to ask “why”.

Page 14: Understanding Variation In Healthcare

Common and Special Cause Variation

• Common cause variation – is always present– Is inherent in the process

• Special cause variation – In addition to common cause variation

it is data that signifies the presence of a signal that needs to be investigated.

• Not knowing the difference can create wasted time and effort for all.

Page 15: Understanding Variation In Healthcare

Taking ActionAction

NeededYes No

Acti

on

Take

nN

oY

es

What rules govern your decision?

Page 16: Understanding Variation In Healthcare

Actions to TakeCommon Cause

• Recognize the variability inherent in the process

• Responding to this variation is a waste of time

• However, the more variation the lower the reliability

• To change the results, change the process

Special Cause

• Differentiate from common cause variation (rules exist for this)

• Find out what happened

• Eliminate or minimize the impact if negative

• Build positive impact into process

Page 17: Understanding Variation In Healthcare

Why Use Run Charts

• “Before and after” data can mask the behavior of a process.

• Run charts allow you to see the behavior of the process.

• Review the following charts that display both “before and after” and run charts.

Page 18: Understanding Variation In Healthcare

Evaluating a Change: Displaying Before and After Results

Change Between Weeks 7 and 8

7.385714286

3

0

1

2

3

4

5

6

7

8

WEEKS 1-7 WEEKS 9-14

Weeks

Ave

rage

Series1

Change Between Weeks 7 and 8

0123456789

10

1 3 5 7 9 11 13 15

Week

Val

ue Series1

Change Made During Week 8

Week-by-Week ValuesAverages of Before and After

Page 19: Understanding Variation In Healthcare

Change During Week Eight

7.285714286

3

0

1

2

3

4

5

6

7

8

WEEKS 1-7 WEEKS 9-14

Weeks

Val

ue Series1

Change Made During Week Eight

0123

45678

910

1 3 5 7 9 11 13 15

Week

Val

ue Series1

Change Made During Week 8

Week-by-Week ValuesAverages of Before and After

Evaluating a Change: Displaying Before and After Results

Page 20: Understanding Variation In Healthcare

Evaluating a Change: Displaying Before and After Results

Change During Week Eight

0123

456789

10

1 3 5 7 9 11 13 15

Weeks

Val

ues

Series1

Change During Week 8

5.285714286

3

0

1

2

3

4

5

6

7

8

WEEKS 1-7 WEEKS 9-14

Weeks

Val

ues

Series1

Change Made During Week 8

Week-by-Week ValuesAverages of Before and After

Page 21: Understanding Variation In Healthcare

Evaluating a Change: Displaying Before and After Results

Change During Week 8

3.714285714

3

0

1

2

3

4

5

6

7

8

WEEKS 1-7 WEEKS 9-14

Weeks

Val

ues

Series1

Change During Week 8

01234

56789

10

1 3 5 7 9 11 13 15

Weeks

Val

ues

Series1

Change Made During Week 8

Week-by-Week ValuesAverages of Before and After

Page 22: Understanding Variation In Healthcare

Summary• “Before and after charts” would

suggest that the changes made at week 8 resulted in improvements.

• Yet when you look at the run charts, data suggest that some of the improvements began before the action was taken. If this improvement was an expensive proposition, the wrong conclusions will be made.

Page 23: Understanding Variation In Healthcare

There are many causes for the variation seen on the run chart. All these must be taken into

consideration. Changing only one may not result in a significant improvement.

Relationship between outcomes and process variables