• Errors in communication and perception
  • What a patient tells us versus how we hear that
  • How deeply we explore the information they give us
• Breakdowns in information gathering (history, examination)
• Breakdowns in integrating and interpreting information (decision making)
• Insufficient knowledge is not actually a major contributor. The biggest problem with inexperience is missing a key sign that would have changed investigation/management

• Cognitive bias affects information we gather and how we interpret information
• Our brain is built to jump to conclusions and make assumptions
• Affects questions we ask on history and thoroughness of examination, what we dismiss as irrelevant
  • Context bias e.g. if someone is tachypnoeic with pins and needles in one hand and this patient is framed as anxious, we may assume this is a patient who is hyperventilating and not examine thoroughly for other causes of tachypnoea
  • Confirmation bias – can exacerbate the above, for instance, if that tachypnoeic patient’s oxygen saturations are normal we may assume their condition is benign as normal oxygen saturations is consistent with hyperventilation
• Can affect how we handover information

• Junior doctors work in environments of high stress
• HALT framework:
  • Hungry
  • Angry
  • Late
  • Tired
• Emotionally distracted e.g. newborn baby, relationship stress can also make us more prone to errors in Type 1 thinking
• Doctors tend to be good at focusing and ignoring distractions
• Invisible gorilla experiment
  • When doctors are asked to count the number of times a basketball player bounces a ball, they can fail to notice the gorilla walking through and waving on the screen
  • 83% of radiologists focusing on a CT, looking for metastases, missed the picture of a gorilla
  • We look for the things we are looking for and miss what else is going on
• Recognise when you are hungry, angry, late or tired and acknowledge this to someone to that they can help you and keep an eye out for you
• Tactical breathing to help focus
• Boxed breathing technique taught to soldiers in the army, to breath in for 3 seconds, hold for 3 seconds then exhale for 3 seconds

• The more experience we have, the more our brain learns to recognise patterns and make faster decisions e.g. like ordering a dish at a familiar restaurant versus a new restaurant
• Type 1 thinking is automatic, rapid thinking, involving jumping to conclusions intuitively
  • Is enough most of the time to get you through the day
  • Is risky at times e.g. if you are hungry, angry, late, tired
  • Is useful at a cardiac arrest, when under time pressure
• Type 2 thinking is true reasoning with analytical, step-by-step processing
• Both types of thinking are necessary
• Need to recognise when Type 1 thinking isn’t enough andto stop and switch to Type 2 thinking
• Heuristics are mental shortcuts that allow people to solve problems and make judgments quickly and efficiently. These rule-of-thumb strategies shorten decision-making time and allow people to function without constantly stopping to think about their next course of action. Heuristics are helpful in many situations, but they can also lead to cognitive biases
• Internship is a period of incredible growth
  • Initially may rely heavily on Type 2 thinking due to new problems faced
  • Gradually transition to Type 1 thinking as experience builds
  • Still need to be aware of when to switch back to Type 2 thinking

• Awareness of the risk of diagnostic error
• Document and work through a differential e.g. what the working diagnosis is, the differentials are, what their pros and cons are and how they will be ruled out
• Often in diagnostic errors the true diagnosis was considered but not thoroughly considered
• Make sure to clearly communicate the working diagnosis with the patient and family and what’s been ruled out- to avoid misunderstandings in what the diagnosis is e.g. in documentation such as discharge letters – also important to communicate this when handing over care to another health worker
• It is important to consider and rule out the worst case scenario
• Red flags to reconsider diagnosis: when things don’t quite fit, a blood test result that doesn’t fit the picture, a lack of response to appropriate treatment e.g. recurrent MET calls
• Often management needs to commence whilst the diagnosis is still uncertain
  • Make sure to handover any uncertainty and flag to the next clinician to continue to look for other things that don’t fit
  • This can increase the chance of making the correct diagnosis

• To question and challenge, in a polite and respectful way
• In root cause analyses, often someone in the team is aware something is not right but is too scared to speak up
• Acknowledge imperfection and when you are not having a good day
• Recognise when things aren’t right
• Ask your team what they are looking for on the tests they request

CEC working on:

• Diagnostic mental time out: stop and plan to engage type 2 thinking
• Red team/blue team thinking exercises
  • If things don’t feel quite right
  • Based on army technique, where blue team aims to argue for what they want to do and how, while the red team aims to question and challenge
  • One member of the team e.g. the registrar can argue for the current diagnoses and way of thinking whilst another member of the team e.g. the junior doctor or consultant can play the devil’s advocate to question and challenge the diagnosis and management
  • Can question and challenge: what is the worst case scenario, is it time critical and have we ruled it out, what are the differentials, are there symptoms that don’t quite fit, do we have all the investigation results we need, do we need to do these investigations
  • Involve the patient as well in how they feel about the direction of management
  • Improves supervision and education
  • Ensures a shared mental model within the team
  • Makes it easier to question and challenge

• Document and work through a differential
• You are only human, allow yourself to be human
• Listen to your gut and if something doesn’t feel quite right, stop and reassess the situation

• Croskerry P, Singhal G, Mamede S. Cognitive debiasing 2: impediments to and strategies for change. BMJ Qual Saf. 2013;22 Suppl 2:ii65-ii72.
• Croskerry P, Singhal G, Mamede S. Cognitive debiasing 1: origins of bias and theory of debiasing. BMJ Qual Saf. 2013;22 Suppl 2:ii58-ii64.
• Mamede S, Splinter TAW, van Gog T, Rikers RMJP, Schmidt HG.  Exploring the role of salient irrelevant clinical features in the emergence of diagnostic errors and the mechanisms through which reflection counteracts mistakes. BMJ Qual Saf. 2012. doi:10.1136/bmjqs-2011-000518.