Dr Al Mulley, Director of the Dartmouth Center for Health Care Delivery Science at Dartmouth College, introduces the theory behind good and bad health care variation, looking at the work of Dr Jack Wennberg in the United States.

1. Reducing Unwarranted Variations
in Health Care
Promoting the Good and Minimizing the Bad
ALBERT G. MULLEY, JR., MD, MPP
THE DARTMOUTH CENTER FOR HEALTH CARE DELIVERY SCIENCE
INTERNATIONAL VISITING FELLOW, THE KING’S FUND
SEPTEMBER 14, LONDON

2. Practice Variation: Rediscovery by Wennberg
Variations in:
• Tonsillectomy: 17-fold
• Hysterectomy: 6-fold
• Prostatectomy: 4-fold
• ‘The need for assessing
outcome of common medical
practices’
• ‘Professional uncertainty
and the problem of supplier-
induced demand’
John E. Wennberg, 1973

3. Practice Variation: US, Norway and the UK
• Geographic variation in rates of
surgical procedures
• Different rates between countries
(US>UK>Norway, or US>Norway>UK)
• Regional variation within countries
similar
McPherson • higher variation: tonsillectomy,
hemorroidectomy, hysterectomy,
prostatectomy
• lower variation: appendectomy,
Hovind hernia repair, cholecystectomy
• Variation a characteristic of the
procedure
Wennberg • Within country variation not associated
with organization or financing of care,
but with professional uncertainty
N Engl J Med 1982; 307: 1310

4. Variation: The Bad and the Good
Bad variation (care not evidence-based)
• Poor research  professional uncertainty
• Poor knowledge  professional ignorance
Good variation (care is patient-centered)
• Clinical differences among patients
• Personal differences among patients
If all variation were bad, it would be easy
JAMA, 1988
to stop it. What is difficult is reducing the
bad variation while keeping the good.

5. The Complexity of Health Care Delivery
High
Disagreement about Chaos
Preferences
Complexity
Control
Low
Low High
Uncertainty about Outcomes
Knowledge-Based

6. Variation: The Bad and the Good
DECREASING BAD VARIATION (evidence-
based care)
• Improve knowledge management
• Improve communication
• No avoidable ignorance
INCREASING GOOD VARIATION (patient-
centered care)
• Recognize clinical differences among
patients
• Honor personal differences among patients
The efficient way to reduce overuse,
underuse, and misuse of care

7. Support for personal knowledge: BPH
How bothersome is urinary dysfunction?
How bothersome will sexual dysfunction be?

8. Simple measures of decision quality: BPH
Knowledge of relevant treatment Concordance between patient
options and outcomes values and care received
1. Are my symptoms likely to be life- 1. How much am I bothered by my
threatening? What if I do nothing? symptoms?
2. Is surgery the only option? How 2. How much will I be bothered by a
much can other treatments help? possible change in experience of sex?
3. Will surgery change my sexual
function? In what ways?
OR = 7.0
Least Most
valued valued
OR = 0.2

9. Simple measures of decision quality: CHD
Knowledge of relevant treatment Concordance between patient
options and outcomes values and care received
1. Are my symptoms likely to be life- 1. How much am I bothered by my
threatening? What if I do nothing? symptoms?
2. Is surgery the only option? How much 2. How much will I be bothered by a
can other treatments help? possible change in cognitive abilities?
3. Will surgery change my ability to think
clearly? In what ways? What else can I
expect in the future?
100
90
CABG
80
70
60
Medical Therapy
50
40
0 2 4 6 8 10 12

10. Impact of Better Decisions for BPH & CHD
Toronto trial
Prostatectomy rates decreased CABG rates decreased 26% to
40% to a rate lower than all but a rate lower than all 306
one of 306 regions

11. The New Yorker, June 1, 2009

12. A Tale of Two Cities: McAllen and El Paso
McAllen $14,946
El Paso $ 7,504

14. Questions raised but not answered

15. Glover’ s discovery and the ethical imperative
•10-fold variation in tonsillectomy
•8-fold risk of death with surgical
treatment
•The response:
•“…these strange bare facts of
incidence…”
•“… tendency for the operation
to be performed for no particular
reason and no particular result.”
•“…sad to reflect that many of
the anesthetic deaths… were
due to unnecessary operations.”
J Allison Glover, 1938