Irrational prescribing because of shifting therapeutic thresholds for sore throats and for coughing
Editor, Butler and co-workers1 conclude that antibiotics are
prescribed for a variety of complex reasons.
In our medical decision analysis study addressing the management of
‘coughing’, we also used a qualitative study: focus groups2 to answer our
first research question: "In patients with coughing as the reason for
encounter, what arguments do general practitioners use to make decisions,
suspecting a respiratory tract infection?"
From our focus groups the key decision in such patients is to prescribe
antibiotics or not. So we asked ourselves: "Are Butler and co-workers’
conclusions congruent with our results?" and " Are their results
transferable to an other clinical setting?"
Concerning the Interviews with general practitioners, our results are
similar, except for the Explanations for irrational prescribing. Bulter
and co-workers state: "The vast majority said they had increased their
prescribing as their knowledge of their patients increased". Quite
opposite we found that more knowledge about patients is less likely
associated with prescribing an antibiotic.
We believe diagnostic uncertainty (mathematically expressed as
probability3) has an important impact on prescribing decisions.
The explanation for irrational prescribing under this condition, is the
use of doctor and patient factors besides the ‘clinical pointers1’.
Because differentiating between bacterial and viral infections is not
possible with any certainty on clinical grounds alone1, general
practitioners quite often get stuck on probabilities of disease within the
test area, defined by Pauker and Kassirer4, leaving them with reasonable
diagnostic doubt. We believe this load of diagnostic uncertainty
determines that factors such as fear of medicolegal problems1 are also
used in decision making. They do not change probabilities of disease.
But we assume general practitioners take them into account to manipulate
their therapeutic thresholds.
Why then do such doctor and patient factors tend to shift the
therapeutic thresholds in favour of prescribing antibiotics? This we
believe is because of chagrin5, e.g. if chagrin on not having prescribed
antibiotics when necessary is higher than on an unnecessary prescription.
This hypothesis frames ‘the variety of complex reasons’.
Looking again at the results of Butler and co-workers, they seem
congruent with our results, with the exception that our general
practitioners seem to have higher tolerance for chagrin with increasing
knowledge of their patients.
Therefor we can transfer the ‘key messages1’ to our clinical setting.
To change prescription habits general practitioners need to develop a
higher tolerance for chagrin in cases of diagnostic uncertainty. By
sharing this doubt and chagrin with their patients?
Drs. Samuel Coenen
Dr. Hugo Van Puymbroeck
Dr. Luc Debaene
Prof. Dr. Paul Van Royen
Prof. Dr. Joke Denekens.
Drs. Samuel Coenen
Research Assistant for the Fund of Scientific Research - Flanders
University of Antwerp - UIA - Centre for General Practice Antwerp
Universiteitsplein 1, B-2610 Antwerp, Belgium
Tel: 00 32 3 820.25.29 Fax: 00 32 3 820.25.26
1. Butler CC, Rollnick S, Pill R, Maggs-Rapport F, Stott N.
Understanding the culture of prescribing: qualitative study of general
practitioners' and patients' perceptions of antibiotics for sore throats.
2. Kitzinger J. Introducing focus groups. BMJ 1995;311(29 July):299-302.
3. Sox jr H. Medical Decision Making: Butterworths, 1988.
4. Pauker S, Kassirer J. The threshold approach to clinical decision
making. NEJM 1980;302(20):1109-17.
5. Feinstein A. The 'Chagrin Factor' and Qualitative Decision Analysis.
Arch Intern Med 1985;145:1257-9.
Competing interests: No competing interests