Assoc Prof Ian Scott
Department of Internal Medicine and Clinical Epidemiology, Princess Alexandra Hospital and Southern School of Medicine, University of Queensland, Brisbane

Dr Ian Scott is consultant general physician and Director of Internal Medicine and Clinical Epidemiology at Princess Alexandra Hospital in Brisbane. He is Associate Professor of Medicine at University of Queensland and Adjunct Associate Professor of Medicine at Monash University. He has research interests in evidence-based medicine, quality improvement, health technology assessment and guideline development, and has co-authored more than 170 articles in peer-reviewed journals. He is a member of Queensland Policy and Advisory Committee on new Technology (QPACT) and sits on the Executive Committee of the CSANZ/NHFA Acute Coronary Syndrome Guidelines Update for 2015 in addition to various working groups of Royal Australasian College of Physicians, Queensland Health, and the Australian Commission of Quality and Safety in Health Care.  


The evolving roles of general physicians – a case of back to basics

Heath care systems are giving more attention to the waste and marginal benefits embedded in current models of care and funding arrangements. Calls are being made for a ‘back to basics’ approach that maximises outcome value for dollars spent. Overdiagnosis  and overtreatment, inappropriate polypharmacy, sub-optimal end of life care, lack of focus on non-medical patient needs, fragmented care of older patients with multi-morbidity, and hospital-centric care delivery are recognised barriers to high value care. General physicians have an opportunity to exert real influence at the level of both clinical care and health policy in countering these barriers using methods which will the subject of this presentation.  

Unnecessary hospitalisation and investigation of low risk patients presenting to hospital with chest pain

Aggarwal L, Perera M, Scott IA*

Department of Internal Medicine and Medical Assessment and Planning Unit, Princess Alexandra Hospital, Brisbane

Objectives: Among patients with undifferentiated chest pain admitted from emergency departments (EDs), less than 20% have acute coronary syndrome (ACS) as final discharge diagnosis suggesting potentially avoidable admissions. This study determined clinical characteristics, risk level, investigations and outcomes of patients with chest pain admitted to a medical assessment and planning unit (MAPU).

Method: Retrospective study of all consecutive patients admitted to MAPU between February and June 2012 for evaluation of chest pain. Demographic data, ECG results, cardiac biomarker levels, Thrombolysis in Myocardial Infarction Score (TIMI score) and results of non-invasive cardiac investigations and coronary angiography were analysed. Outcome measures comprised confirmed ACS, all-cause death, and readmissions to hospital over six months follow-up.

Results: 321 patients were studied aged 58.5 +/- SD 14.2 years with TIMI score of 1.8 (+/-1.7). Exercise stress test and computerised tomography of the coronary arteries were performed in 16.5% and 13.7% of patients respectively, with a combined positivity rate for probable coronary artery disease (CAD) of 3.5%. At discharge, 31(9.6%) patients were diagnosed with ACS, of whom 25 (80.6%) were diagnosed in ED prior to MAPU admission. Of 290 patients with initially negative investigations in ED, only six (2.0%) were subsequently diagnosed with ACS during hospital stay. At 6 months follow-up, only one patient (0.3%) represented with ACS and two (0.6%) died of non-coronary causes. Among 165 patients (51.4% of total cohort) with TIMI score of 0 or 1, only seven (4.2%) had confirmed ACS at discharge; none were readmitted with ACS or died up to 6 months.

Conclusion: More than 9 out of 10 patients admitted to MAPU for evaluation of chest pain after initially negative investigations in ED have a very low risk of ACS, death or cardiac-related readmission at 6 months. Further in-patient testing has very low yield for CAD. Strategies are needed to identify such patients and facilitate their early discharge. 

Underuse of risk assessment and overuse of CTPA in patients with suspected pulmonary thromboembolism

Aggarwal L, Perera M, Scott IA*

Department of Internal Medicine and Medical Assessment and Planning Unit,

Princess Alexandra Hospital, Brisbane.

Objectives: Increasing use of computerised tomography pulmonary angiography (CTPA) in patients with suspected pulmonary thromboembolism (PTE) without commensurate improvement in clinical outcomes suggests possible overuse. This study assessed the use and clinical utility of pre-test clinical prediction rules and D-Dimer assays in ruling PTE in or out in patients presenting to hospital with suspected PTE, and identifying those who warrant CTPA.

Methods: All consecutive patients undergoing CTPA at a tertiary hospital between August 1st and December 31st 2013 were studied retrospectively. Use of D-dimer assays and clinical prediction rules for PTE were evaluated by review of clinical notes. For each patient, a modified Wells score (mWS), revised Geneva score (rGS) and PISA model  were calculated retrospectively and performance characteristics for PTE determined in reference to CTPA results. Results for the mWS and D-dimer assays (when performed) were used to estimate overuse of CTPA according to risk category. 

Results: Of 344 patients undergoing CTPA, 53 (15.4%) were diagnosed with PTE.  Use of a pre-test PTE prediction rule was documented in only 5.0% of patients. Of 269 low risk patients (78.2% of total cohort) who had a calculated mWS ≤4, only 64 (23.8%) had a D-Dimer assay performed, and only 30 (11.1%) had PTE on CTPA.  Among 75 patients with a mWS >4, 23 (30.7%) had PTE on CTPA (p<0.001). Of all prediction rules, a high risk mWS had the highest positive predictive value (31%) for PTE in this cohort; all rules demonstrated similar negative predictive values for low risk scores (between 87% and 89%). After adjusting for 11% false negative rate for PTE in patients with low risk mWS, avoidable overuse of CTPA was possible in up to 190 (55.2%) patients.

Conclusion: Use of clinical prediction rules and D-dimer use need to be systematised in emergency medicine practice in facilitating more selective use of CTPA in suspected PTE.

 The elephants in the room – the role of cognitive biases in overdiagnosis and overtreatment

Scott IA*, Soon J, Elshaug A, Lindner R.

*Director of Internal Medicine and Clinical Epidemiology, Princess Alexandra Hospital; Associate Professor of Medicine, University of Queensland, Brisbane

Background: Among the many drivers of low value care, the role of cognitive biases in clinician decision-making deserve greater attention. Strategies frequently adopted to counter low value care – such as education programs, guidelines, and audit and feedback – are based on rationalist principles (ie system 2 thinking). However, clinical decision making often defaults to mindlines and heuristics (ie System 1 thinking) based on highly personal and internalised beliefs vulnerable to cognitive bias.

Methods: A narrative review of relevant literature combined with insights from authors’ experience in leading overuse minimisation projects were employed in identifying several biases and strategies for overcoming them. These will be illustrated using clinical examples.

Results: Common biases include: clinician regret of omission (or loss aversion), availability heuristic, optimism and outcome bias, confirmation bias and framing effects, innovation (or novelty) bias, endowment effects and sunken costs fallacy, extrapolation bias, affect and authority bias, certainty and reassurance needs, and groupthink.

Debiasing strategies include: cognitive autopsies and huddles for sharing discomfort with uncertainty and omission regret, ‘teachable moment’ narratives of patient harm that invert availability heuristics, emphasising gains over losses in clinical outcomes, reframing overuse messaging from negative to positive, presenting avoidance of low value care as innovative renewal, offering alternative forms of care to nullify endowment effects and sunken costs fallacy, building equipoise for more research to counter extrapolation bias, using normalisation of deviance and nudge techniques to preserve autonomy, and deploying shared decision-making.

Conclusion: Cognitive and psychosocial factors that influence clinician decision-making deserve more attention in determining ways in which behavioural economics can be used to minimise overuse of care.