Think Twice

used in internal medicine to arrive at a diagnosis. The diagnostic approaches used in general practice perplexed and intrigued me, and led me to the research of Amos Tversky and Daniel Kahneman, and their paper on making judgements in conditions of uncertainty. 1 What was happening in general practice? I conducted a study involving all 20 GPs in a Hampshire market town, to whom I presented a series of vignettes of patients with dyspepsia, and asked them to tell me, for each vignette, what further information they would need to make a diagnosis or management plan, and conclude the consultation. 2 There were large differences between doctors in the number and nature of the pieces of information that they required and the time taken to complete these ‘consultations’. In contrast with previous research there was no correlation between the professional experience of my subjects and the amount and nature of data they collected. With hindsight, it was perfectly obvious that I was observing the interplay between Type 1 and Type 2 thinking, described in Kahneman’s 2011 book Thinking, Fast and Slow . 3 I just couldn’t see it. I went on to edit the British Journal of General Practice . Kahneman went on to win the Nobel Prize in economics for his work on prospect theory and the psychology of judgement and decision making. But is he happy? Type 1 reasoning is rapid, intuitive, automatic and unconscious; it generates the diagnosis that forms in our mind when we see a patient’s name on the surgery list, or observe her rising from the chair in the waiting room. Type 2 reasoning is slower, more logical, analytical, conscious and effortful. It includes the search for confirming and disconfirming evidence, obtaining and acting on the results of investigations, being willing to let go your earlier, cherished diagnosis, and recognising that relying on your personal heuristics — short cuts to diagnosis — may sometimes take you down a blind alley. Diagnostic safety-netting, if you like. Diagnosis is the theme of this month’s BJGP , with articles related to many aspects of diagnosis in general practice. There are the challenges of making an accurate diagnosis when no diagnostic test is available, as in IBS, and the likely impacts of genomics, point-of-care testing, and computerised decision support systems. In the future these may have the capacity to synthesise the content of the electronic medical record with the presenting complaint, the clinical signs, and diagnostic tests, including genetic testing, in ways that are now just about imaginable. Observations like those made by Chris Burton and colleagues on the interplay of abdominal pain and pelvic symptoms in the years leading up to a final diagnosis of endometriosis are likely to form the substrate of these diagnostic support systems. Gentle reminders about considering coeliac disease in the IBS scenario, and hyperaldosteronism in the hypertension case could transform the role of the third person in the consultation: the computer. One of the most compelling examples of Types 1 and 2 thinking, or at least of the difference between the intuitive and the empirical, in medicine is tangentially linked to Chris Murphy’s article about humility, in which the great Scottish philosopher David Hume plays a part. On his sick bed, Hume had gathered the wisest physicians of the day around him. They offered a range of diagnostic possibilities, which Hume considered fanciful, not least because no one had actually examined him. Fortunately he was visited by John Hunter, empiricism incarnate, who palpated Hume’s abdomen to find the malignant liver; giving Hume an answer for which he was immensely grateful. Think twice — it’s alright. Roger Jones, Editor

1. Tversky A, Kahneman D. Judgement under uncertainty: heuristics and biases. Science 1974; 185 (4157): 1124–1131. 2. Jones RH. Data collection in decision-making: a study in general practice. Med Educ 1987, 21(2): 99–104. 3. Kahneman D. Thinking, fast and slow . New York, NY: Farrar, Straus and Giroux, 2011. DOI: https://doi.org/10.3399/bjgp17X693521 © British Journal of General Practice 2017; 67: 537–584 EDITOR Roger Jones, DM, FRCP, FRCGP, FMedSci London DEPUTY EDITOR Euan Lawson, FRCGP, FHEA, DCH Lancaster JOURNAL MANAGER Catharine Hull SENIOR ASSISTANT EDITOR Amanda May-Jones WEB EDITOR Erika Niesner ASSISTANT EDITOR Moira Davies ASSISTANT EDITOR Tony Nixon DIGITAL & DESIGN EDITOR Simone Jemmott EDITORIAL ASSISTANT Margaret Searle EDITORIAL ADMINISTRATOR Mona Lindsay EDITORIAL BOARD Sarah Alderson, MRCGP, DRCOG, DFRSH Leeds Luke Allen, MBChB, MPH, PGCE Clin Edu Oxford Hajira Dambha-Miller, MSc, MPhil, MBBS Cambridge Jessica Drinkwater, MRes, MRCGP, DFRSH Leeds Graham Easton, MSc, MRCGP London Adam Firth, MBChB, DTM&H, DipPalMed Manchester Claire Gilbert, BA, MPH, MRCGP, PGCME, DCH Yorkshire and the Humber Benedict Hayhoe, LLM, MD, MRCGP, DRCOG, DPMSA London Jennifer Johnston, PhD, MRCGP Belfast Nada Khan, MSc, DPhil, MBBS Leeds Peter Murchie, MSc, PhD, FRCGP Aberdeen Joanne Reeve, PhD, FRCGP, DFPH Hull Liam Smeeth, MSc, PhD, FRCGP, FFPH London STATISTICAL ADVISORS Richard Hooper, Sally Kerry, Peter Schofield, and Obioha Ukoumunne SENIOR ETHICS ADVISOR David Misselbrook, MSc, MA, FRCGP 2016 impact factor: 2.760 EDITORIAL OFFICE 30 Euston Square, London, NW1 2FB. (Tel: 020 3188 7400, Fax: 020 3188 7401). E-mail: [email protected] / bjgp.org / @BJGPjournal PUBLISHED BY The Royal College of General Practitioners. Registered charity number 223106. The BJGP is published by the RCGP, but has complete editorial independence. Opinions expressed in the BJGP should not be taken to represent the policy of the RCGP unless this is specifically stated. No endorsement of any advertisement is implied or intended by the RCGP. ISSN 0960-1643 (Print) ISSN 1478-5242 (Online) British Journal of General Practice, December 2017 539 PRINTED BY WARNERS 01778 395111