Clinical decision making

Carl ThompsonUK, Centre for Evidence Based Nursing

Editor, Evidence Based Nursing

www.ebn.bmj.com

This session

Integrating research evidence with preferences and contextual informationThe ways people think and make choices

When should intuition and more structured approaches be used?What’s right and wrong with clinical

experience?Tools and techniques: decision analysis,

cognitive approaches

How do nurses (and doctors) think they think?

1. Make sense of multiple cues

2. Diagnose or assess3. Treat or intervene4. Evaluate progress5. Treat some more if

needed

Errr… start again…

How do they actually think?

The theory – cognitive continuum

Hamm,R (1988) in Dowie & Elstein, Clinical Judgement and decision making, Cambridge University Press

Daniel Kahneman and Amos Tversky (d. 1996) Tversky and Kahneman, Judgment Under Uncertainty: Heuristics and Biases, Science (1974), Vol. 185, pp 1124-1131

Heuristics and Bias

The Need to Assess Probabilities

People need to make decisions constantly: diagnosis and therapy

Thus, people need to assess probabilities to classify objects or predict various values, such as p (DISEASE|SYMPTOMS)

People employ heuristics to assess probabilities heuristics lead to significant biases,

CONSISTENTLY This observation leads to a descriptive, rather than a

normative, theory of human probability assessment

“Getting” healthcare is not easy

Pattern recognition is easier if you have experience

Experience: A problem of perceptionSlide from Slawson, Shaughnessy, Becker, 1999.

Do you see the Dalmation in the picture? Moral: Clinical experience sometimes helps see, sometimes prevents seeing the right pictureNow that you see it, can you try to not see it?Moral: Experience can result in ideas that are difficult to change

One learns the basic patterns

One sees them in new situations.

Then one can see the pattern where before it had been confusing.

Time and nursing decisions

Once every 30 seconds in critical care (Bucknall, 2000)

Circa 50 decisions every 8 hour shift in Medical Admissions (Thompson et al. 2001 – 2005)

5 judgement or decision challenges per consult for health visitors.

Remember uncertainty?

How do we normally respond? Experiential/internal knowledge Very limited textual information use and for certain

kinds of decisions (British National Formulary and local protocols)

90 hours of primary care = 1 telephone call 180 hours of acute care (1080 decisions) = local protocols

x4 times, BNF x50 times).

‘sophistication’ and technology doesn’t matter (Randell et al. 2007).

Demography and biography poor predictors of use

The five classic decision pitfalls

Representativeness and base rate neglect

AvailabilityOverconfidenceConfirmationIllusory correlations

What can we do?

Think about decision structure, time & visibility Be aware of base rates Consider whether information is truly relevant

and not just salient Seek reasons why you may be wrong and

entertain alternatives Ask questions that may disprove, rather than

confirm, your current hº You are wrong more often than you think