4. Definition
Postgraduate Course
Evidence-based management means making decisions
about the management of employees, teams or
organizations through the conscientious, explicit and
judicious use of four sources of information:
1. The best available scientific evidence
2. Organizational facts, metrics and characteristics
3. Stakeholders’ values and concerns
4. Practitioner expertise and judgment
12. Postgraduate Course
elderly people who have give them a drug that
an irregular heartbeat are reduces the
much more likely to die of number of
coronary disease irregular beats
13. How 40,000 cardiologists can be wrong
Postgraduate Course
In the early 1980s newly introduced anti-
arrhythmic drugs were found to be highly
successful at suppressing arrhythmias.
Not until a RCT was performed was it realized
that, although these drugs suppressed
arrhythmias, they actually increased mortality.
The CAST trial revealed Excess mortality of
56/1000.
By the time the results of this trial were
published, at least 100,000 such patients had
been taking these drugs.
14. Errors and Biases of Human Judgment
Postgraduate Course
Doctors and managers hold many erroneous beliefs,
not because they are ignorant or stupid, but because
they seem to be the most sensible conclusion
consistent with their own professional experience!
available evidence.
15. Problem II: false information
Postgraduate Course
Half of what you learn will be shown to be either dead
wrong or out-of-date within 7 years of your graduation;
the trouble is that nobody can tell you which half
Sackett: remember that your teachers are full of crap,
just like your parents.
16. Evidence-based?
Postgraduate Course
1. Incompetent people benefit more from feedback than
highly competent people.
2. Task conflict improves work group performance while
relational conflict harms it.
3. Being intelligent is a disadvantage for performing low
skilled jobs.
17. Evidence-based?
Postgraduate Course
Competentie management
Excellente zorg
Kwaliteits management
Het nieuwe werken
Kennis management
Magnet, Investors in People
Plain Tree, Healing Environment
Balanced Score Card / INK
Lean / Six Sigma / TOC
18. Postgraduate Course
Don’t be a parrot!
Think critically about experience,
question your assumptions, and
challenge what you think you know.
(Show me the evidence!)
20. 5-step approach
Postgraduate Course
1. Formulate a focused question
2. Searching for the best available evidence
3. Critical appraisal
4. Turning evidence into practice
5. Monitor the outcome
26. Type vraag: effect
Postgraduate Course
Werkt het?
Werkt het beter dan ....?
Effect Heeft het een effect op ....?
Wat zijn de succesfactoren voor ....?
Wat is nodig om het te laten werken?
27. Type: non-effect
Postgraduate Course
Needs: Wat hebben mensen nodig, waar hebben ze
behoefte aan?
Attitude: Wat denken of vinden mensen van ...?
Experience: Wat zijn de ervaringen van mensen met ...?
Prevalence: Hoeveel mensen / organisaties ....?
Procedure: Hoe kunnen we .... implementeren?
Explanation: Waarom werkt het?
Economics: Hoeveel kost het (tijd en geld)?
28. Which design for which question?
Postgraduate Course
Explanation
31. What is evidence?
Postgraduate Course
Evidence is not the same as ‘proof’ or ‘hard facts’
Evidence can be
- so strong that no one doubts its correctness, or
- so weak that it is hardly convincing at all
32. Postgraduate Course
The best available evidence =
Studies with the highest internal validity
Studies with the highest external validity
33. Internal validity
Postgraduate Course
internal validity = indicates to what extent the
results of the research may be biased and is
thus a comment on the degree to which
alternative explanations for the outcome found
are possible (confounding).
34. Confounding
Postgraduate Course
Confounding is the idea that a 3rd variable can distort or
confuse (or confound..) a relationship between two other
variables. For instance, when factor X causes disease Y,
that relationship could be confounded by factor C that is
associated with both factor X and disease Y. C would be
an alternative explanation for the relationship observed
between X and Y.
35. What are the confounders?
Postgraduate Course
1. Shoe size & quality of handwriting
2. Body length & body weight
3. Number of storks & birth rate
4. Smoking youngsters & better lung function
37. Levels of internal validity
Postgraduate Course
1. Were there enough subjects in the study?
2. Was a control group used?
3. Were the subjects randomly assigned?
4. Was a pretest used?
5. Was the study started prior to the intervention or event?
6. Was the outcome measured in an objective and reliable way?
6x yes = very high (A)
5x yes = high (A)
4-3x yes = limited (B)
2x yes = low (C)
1-0x yes = very low (D)
41. External validity: generalizability
Postgraduate Course
Always ask yourself to what extent the evidence
is generalizable to your situation:
Ecological validity: Is your organization so different from
those in the study that its results may be difficult to apply?
Population validity: Is your population so different from
those in the study that its results may be difficult to apply?
42. Generalizability
Postgraduate Course
Keep in mind:
What works in one narrowly defined setting
might not work in another,
but some psychological principles
are generalizable to all human beings.