Presentation on theme: "CLINICAL REASONING IN GENERAL PRACTICE Dr Charles Todd."— Presentation transcript:
CLINICAL REASONING IN GENERAL PRACTICE Dr Charles Todd
OBJECTIVES At the end of the session you should: Understand cognitive methods utilised in making a diagnosis Recognise some of the special features that apply in general practice Have a strengthened ability to reach an accurate diagnosis in the general practice consultation Understand how and why errors in reasoning occur
KEY MESSAGE: STOP & THINK! Remember this antismoking slogan? Plus message spray painted over it… THINK FIRST - MOST DOCTORS DON’T SMOKE Smoke first – Most doctors don’t think!
WHY IMPORTANT? Diagnostic errors: i.Common: estimates 10-20%. ii.Among medical errors are the second leading cause of adverse effects (after medication errors) iii.Associated with high morbidity. iv.The most common and most costly source of malpractice payments (in UK & USA).
GENERAL PRACTICE CONSULTATIONS Short Enormously varied Problems undifferentiated Serious disease uncommon Multiple tasks: the key one is to establish the reasons for the patient’s attendance – with new problems this means reaching a diagnosis
MAKING A DIAGNOSIS Key competency for GPs Forms the basis for determining the patient’s treatment, prognosis, etc Concerns moving “backwards” from the patient’s complaints (the illness) to the disease (target disorder) Important to consider physical, social and psychological aspects The history is critical – examination and investigations play a relatively small role
KAHNEMAN’S SYSTEMS OF THINKING System 1 operates automatically and quickly, with little effort System 2 involves effortful mental activity While most of the time system 1 is in operation, system 2 can to some extent overrule it We can “toggle” between the two
CLINICAL PROBLEM SOLVING IN PRACTICE What methods are used in reaching a diagnosis? 1)Intuition 2)Hypothesis generation and testing 3)Follow a structured guideline or algorithm
INTUITION Instant realisation that the presenting signs and symptoms conform to an already known pattern Reflex rather than reflective Applies where the presentations is very familiar “Pattern recognition” Kahneman’s System 1
HYPOTHETICO-DEDUCTIVE METHOD Analytical approach Laboured, time-consuming Kahneman’s System 2 Ideas are generated during the interview about what the underlying problem is These “hypotheses” are then tested and refined by further questions, examination and investigations
MORE ON HYPOTHESES Hypotheses are “explanatory ideas” that are increasingly refined through the consultation The first are generated very early on in history taking (within seconds) Usual strategy followed is to “prove” rather than refute a particular hypothesis Used by clinicians of all types – more experienced are better at it
GENERATING HYPOTHESES Consider: Probability or likelihood of a given condition in a specific setting Potential seriousness and Treatability of any possible diagnosis – especially with regard to the value of early detection
WHEN THE GOING GETS TOUGH Consider broad categories first, e.g. think about what system is involved Keep an open mind Look for a unifying diagnosis Utilise checklists as aide-memoires Avoid fishing expeditions Listen to the patient and think!
SOURCES OF ERROR AND BIAS Jumping to conclusions and fixing on them – being “blind” to other ideas Basing diagnosis on recall of a similar case from the past or novelty, rather than awareness of epidemiology in the setting Continuing reference to existing and/or extension of existing diagnostic label Unquestioning faith in diagnostic labels applied by others, especially consultants Failure to reassess when things don’t fit with what is expected Being distracted by too much information Focus on ruling in rather than ruling in
ERROR AND BIAS (ctd) Confirmation bias: focus on ruling in rather than refuting a particular diagnosis (i.e. only seeking evidence to confirm) Over-reliance on results of investigations “Colluding” with the patient who is asking for reassurance Multiple doctors involved failure to see the bigger picture Emotional factors / denial Being too tired or rushed Lack of knowledge and experience
EXAMPLES FROM PRIMARY CARE SIGNIFICANT EVENTS PresentationInitial diagnosisEventual diagnosisReason for error 60 yr old rectal bleeding HaemorrhoidsRectal cancerInexperience Failure to follow guidelines 2 yr old unwell with fever, unusual blanching rash Viral infectionMeningococcal septicaemia “Blindness” and collusion 40 yr old obese type 2 DM with severe recurrent vertigo LabyrinthitisCerebellar strokeMultiple doctors Failure to reassess
COMMUNICATION SKILLS FOR BETTER DIAGNOSIS Listen – and show it Don’t interrupt (“the golden minute”) Ask open-ended questions first, then more directed ones Be receptive to all verbal and non-verbal cues Summarise and check Be open to the patient’s perspective (ICE)
SPECIAL CONSIDERATIONS IN GENERAL PRACTICE Be pragmatic and action oriented Use time judiciously Don’t trust specialists uncritically Learn to live with uncertainty Manage risk Identify and respond to the patient’s ideas about what is wrong
USE OF CLINICAL EPIDEMIOLOGY TO IMPROVE DIAGNOSTIC ACCURACY Statistical methods are underutilised in reaching a diagnosis Estimate initial probability of disease (prevalence in the setting) Know specificity and sensitivity of diagnostic tests Refine probability based on strength of evidence (“likelihood ratio”)
FINAL TIPS Generate more than one possible diagnositic idea Think of the worst thing this could be Don’t just focus on presenting symptoms: review recent consultations and look at bigger picture Always be ready to reconsider or ask a colleague Listen to your gut, but Never abandon your critical faculties
READING Sackett D, Haynes et al. Clinical Epidemiology. A Basic Science for Clinical Medicine. Little Brown Elstein A, Schwarz A. Clinical problem solving and diagnostic decision making... BMJ 2002; 324: more-common-and-harmful-for-patients/ Scott I. Errors in clinical reasoning: causes and remedial strategies. BMJ 2009; 339: Fraser R. Clinical Method: a general practice approach. Butterworth Heinemann. Kahneman D. Thinking, Fast and Slow. Penguin, 2012