Imperial College London


Faculty of MedicineDepartment of Surgery & Cancer

Reader in Medical Decision Making



o.kostopoulou Website




5.07Medical SchoolSt Mary's Campus





Olga is an applied experimental psychologist studying judgement and decision making. Her main focus is the application of Psychology theory, evidence and experimental methods to the study of medical decisions. She has conducted research on professional judgement and decision making in a variety of healthcare contexts, including dentistry, neonatal and adult intensive care, surgery, and primary care. As Principal Investigator and Co-investigator, she has obtained funding from the Department of Health, Cancer Research UK, and the European Commission for studies in diagnosis, diagnostic error, decision support, and referral decision making. 

Olga was the 2021-22 President of the Society for Medical Decision Making (SMDM). In the past, she served SMDM as President-Elect (2020-21), Immediate Past President and Chair of the Nominations Committee (2022-23), and International Trustee (2013-2016). She organised and chaired the 16th biennial European SMDM meeting (London, 12-14 June, 2016).

She is Associate Editor of Medical Decision Making and Frontiers in Cognition (Reason and Decision-Making section).


  • Decision making processes
  • Behaviour change through boosting or nudging
  • The communication of risk and uncertainty
  • Decision aids, algorithms, decision support systems: their design, use, and interaction with human judgement
  • Individual differences in judgement and decision making

Decision Psychology Research group:


1. Cancer Research UK project award: "Cancer risk algorithms and their influence on clinical judgement." Amount awarded: £382,853. From February 2020 to October 2024.

Olga Kostopoulou (PI). Researchers: Bence Pálfi (Postdoctoral Research Associate), Kavleen Arora (Clinical Research Fellow).

2. Cancer Research UK project award: "Demonstrating the feasibility of a Learning Health System for cancer diagnosis in primary care." PI: Brendan Delaney.

Olga Kostopoulou: Co-I, Work package lead. Amount allocated: £202,675. 2018-2021. Researcher: Christian Ramtale.

3. Cancer Research UK project award: "Investigating delays in the detection of early cancers: an exploration of GPs' decision making based on Signal Detection Theory." Amount awarded: £308,944. From March 2016 to February 2019.

Olga Kostopoulou (PI). Co-investigators: Brendan Delaney, Francesca Fiorentino. Researcher: Martine Nurek.

4. Cancer Research UK project award: "An investigation of the cognitive factors for missing early presentations of cancer in primary care". Amount awarded: £330,772. From September 2011 to December 2015.

Olga Kostopoulou (PI). Co-investigator: Brendan Delaney. Researchers: Miroslav Sirota, Thomas Round, Shyamalee Samaranayaka. 

5. EU FP7 programme grant: Translational Research and Patient Safety in Europe (TRANSFoRm)- Scientific co-ordinator: Brendan Delaney. From March 2010 to May 2015

Olga Kostopoulou (Lead of Work Package 2: "Developing diagnostic support for primary care"). Researchers: Andrea Rosen, Thomas Round, Talya Porat. Amount allocated to WP2: €594,554



  • Camille Lakhlifi. ‘Exploration of Physicians’ metacognition’. (Supervisor: Benjamin Rohaut) Paris Brain Institute (Institut du Cerveau) and French Health Authority (Haute Autorité de Santé). Paris, November 2023.
  • Angela Lilly. ‘How Do Statutory Social Workers Formulate Judgements and Decisions About Well-Being?'(Supervisors: Tim Rakow & Ben Gardner). King’s College London. 4/5/2023
  • Marine Hainguerlot. ‘Probability distortion in medical decision making: Field evidence, laboratory experiments, and statistical aids’. (Supervisors: Vincent de Gardelle & Jean-Christophe Vergnaud). Université Paris 1 Panthéon Sorbonne, UFR de Sciences Economiques. Paris, 21/12/2017.
  • Yasmina Okan. ‘How to improve the comprehension and communication of medical risks and health’, (Supervisor: Rocío García-Retamero) University of Granada, Spain, 20/12/2013.
  • Jane Heyhoe. ‘Affective and cognitive influences on decision making in healthcare’ (supervisor: Rebecca Lawton) Institute of Psychological Sciences, University of Leeds. 26/9/2013.
  • Laura Zwaan. ‘Diagnostic reasoning and diagnostic error in Medicine’. (supervisor: Daniëlle Timmermans) Department of Public and Occupational Health, VU University Medical Center, Amsterdam, NL. 16/03/2012.


Ploutarchos Kourtidis. "Influences of a diagnostic decision aid on physicians’ thinking". Graduated 2022. Funding: NIHR Imperial PSTRC.

Martine Nurek. "Predecisional information distortion in physicians' diagnostic judgements". Graduated 2017. Funding: LISS-DTP (London Interdisciplinary Social Science Doctoral Training Partnership).

Amanda Woolley. "Clinical Intuition in General Practice: A Cognitive Psychology Perspective". Graduated 2015. Funding: Departmental Doctoral grant.

Visiting Researcher: 

Dafina Petrova (Mind, Brain, & Behavior Research Center, University of Granada, Spain) - September to December 2015 

Olga is looking for exceptional candidates willing to apply to the London Interdisciplinary Social Science Doctoral Training Partnership (LISS DTP) and the President's PhD Scholarship scheme, and early career postdocs for the highly-competitive Imperial College Research Fellowships

Selected Publications

Journal Articles

Blanchard MD, Herzog SM, Kämmer JE, et al., 2024, Collective Intelligence Increases Diagnostic Accuracy in a General Practice Setting., Med Decis Making

Pálfi B, Arora K, Prociuk D, et al., 2024, Risk prediction algorithms and clinical judgment: Impact of advice distance, social proof, and feature-importance explanations, Computers in Human Behavior, Vol:153, ISSN:0747-5632

Sirota M, Habersaat KB, Betsch C, et al., 2024, We must harness the power of social and behavioural science against the growing pandemic of antimicrobial resistance, Nature Human Behaviour, Vol:8, ISSN:2397-3374, Pages:11-13

Nurek M, Kostopoulou O, 2023, How the UK public views the use of diagnostic decision aids by physicians: a vignette-based experiment, Journal of the American Medical Informatics Association, Vol:30, ISSN:1067-5027, Pages:888-898

Nurek M, Hay AD, Kostopoulou O, 2023, Online experiment comparing GPs’ antibiotic prescribing decisions to a clinical prediction rule, British Journal of General Practice, Vol:73, ISSN:0960-1643, Pages:e176-e185

Kourtidis P, Nurek M, Delaney B, et al., 2022, Influences of early diagnostic suggestions on clinical reasoning, Cognitive Research: Principles and Implications, Vol:7, ISSN:2365-7464

Palfi B, Arora K, Kostopoulou O, 2022, Algorithm-based advice taking and clinical judgement: impact of advice distance and algorithm information, Cognitive Research: Principles and Implications, Vol:7, ISSN:2365-7464

Kostopoulou O, Arora K, Palfi B, 2022, Using cancer risk algorithms to improve risk estimates and referral decisions, Communications Medicine, Vol:2, ISSN:2730-664X

Kostopoulou O, Schwartz A, 2021, To unpack or not? Testing public health messaging about COVID-19, Journal of Experimental Psychology-Applied, Vol:27, ISSN:1076-898X, Pages:751-761

Kostopoulou O, Tracey C, Delaney B, 2021, Can decision support combat incompleteness and bias in routine primary care data?, Journal of the American Medical Informatics Association, ISSN:1067-5027

Kostopoulou O, Nurek M, Delaney B, 2020, Disentangling the relationship between physician and organizational performance: a signal detection approach, Medical Decision Making, Vol:40, ISSN:0272-989X, Pages:746-755

Nurek M, Delaney BC, Kostopoulou O, 2020, Risk assessment and antibiotic prescribing decisions in children presenting to UK primary care with cough: a vignette study, Bmj Open, Vol:10, ISSN:2044-6055

Kostopoulou O, Nurek M, Cantarella S, et al., 2019, Referral decision making of General Practitioners: a signal detection study, Medical Decision Making, Vol:39, ISSN:0272-989X, Pages:21-31

Petrova D, Kostopoulou O, Delaney BD, et al., 2018, Strengths and gaps in physicians’ risk communication: a scenario study of the influence of numeracy on cancer screening communication, Medical Decision Making, Vol:38, ISSN:0272-989X, Pages:355-365

Porat T, Delaney BC, Kostopoulou, 2017, The impact of a diagnostic decision support system on the consultation: perceptions of GPs and patients, BMC Medical Informatics and Decision Making, Vol:17, ISSN:1472-6947

Sirota M, Kostopoulou O, Round T, et al., 2017, Prevalence and alternative explanations influence cancer diagnosis: an experimental study with physicians, Health Psychology, Vol:36, ISSN:1930-7810, Pages:477-485

Sirota M, Round T, Samaranayaka S, et al., 2017, Expectations for antibiotics increase their prescribing: causal evidence about localized impact, Health Psychology, Vol:36, ISSN:1930-7810, Pages:402-409

Kostopoulou O, Porat T, Corrigan D, et al., 2017, Diagnostic accuracy of GPs when using an early-intervention decision support system: a high-fidelity simulation, British Journal of General Practice, Vol:67, ISSN:1478-5242, Pages:e201-e208

Nurek M, Kostopoulou O, 2016, What You Find Depends on How You Measure It: Reactivity of Response Scales Measuring Predecisional Information Distortion in Medical Diagnosis, PLOS One, Vol:11, ISSN:1932-6203

Kostopoulou O, 2006, The transient nature of utilities and health preferences, Medical Decision Making, Vol:26, ISSN:0272-989X, Pages:304-306

Kostopoulou O, Sirota M, Round T, et al., 2016, The role of physicians’ first impressions in the diagnosis of possible cancers without alarm symptoms, Medical Decision Making, Vol:37, ISSN:1552-681X, Pages:9-16

Porat T, Kostopoulou O, Woolley A, et al., 2015, Eliciting user decision requirements for designing computerized diagnostic support for family physicians, Journal of Cognitive Engineering and Decision Making, Vol:10, ISSN:1555-3434, Pages:57-73

Kostopoulou O, Lionis C, Angelaki A, et al., 2015, Early diagnostic suggestions improve accuracy of family physicians: a randomized controlled trial in Greece., Family Practice, Vol:32, ISSN:1460-2229, Pages:323-328

Vadillo MA, Kostopoulou O, Shanks DR, 2015, A critical review and meta-analysis of the unconscious thought effect in medical decision making, Frontiers in Psychology, Vol:6, ISSN:1664-1078

Woolley A, Kostopoulou O, Delaney BC, 2015, Can medical diagnosis benefit from "unconscious thought"?, Medical Decision Making, Vol:36, ISSN:1552-681X, Pages:541-549

Kostopoulou O, Rosen A, Round T, et al., 2015, Early diagnostic suggestions improve accuracy of GPs: a randomised controlled trial using computer-simulated patients, British Journal of General Practice, Vol:65, ISSN:0960-1643, Pages:E49-E54

Nurek M, Kostopoulou O, Hagmayer Y, 2014, Predecisional information distortion in physicians’ diagnostic judgments: Strengthening a leading hypothesis or weakening its competitor?, Judgment and Decision Making, Vol:9, ISSN:1930-2975, Pages:572-585

Sirota M, Juanchich M, Kostopoulou O, et al., 2014, Decisive Evidence on a Smaller-Than-YouThink Phenomenon: Revisiting the "1-in-X'' Effect on Subjective Medical Probabilities, Medical Decision Making, Vol:34, ISSN:0272-989X, Pages:419-429

Woolley A, Kostopoulou O, 2013, Clinical Intuition in Family Medicine: More Than First Impressions, Annals of Family Medicine, Vol:11, ISSN:1544-1709, Pages:60-66

Kostopoulou O, Russo JE, Keenan G, et al., 2012, Information Distortion in Physicians' Diagnostic Judgments, Medical Decision Making, Vol:32, ISSN:0272-989X, Pages:831-839

Kostopoulou O, Mousoulis C, Delaney BC, 2009, Information search and information distortion in the diagnosis of an ambiguous presentation, Judgment and Decision Making, Vol:4, ISSN:1930-2975, Pages:408-418

Kostopoulou O, Devereaux-Walsh C, Delaney BC, 2009, Missing Celiac Disease in Family Medicine: The Importance of Hypothesis Generation, Medical Decision Making, Vol:29, ISSN:0272-989X, Pages:282-290

Kostopoulou O, Delaney BC, Munro CW, 2008, Diagnostic difficulty and error in primary care - a systematic review, Family Practice, Vol:25, ISSN:0263-2136, Pages:400-413

Kostopoulou O, Oudhoff J, Nath R, et al., 2008, Predictors of diagnostic accuracy and safe management in difficult diagnostic problems in family medicine, Medical Decision Making, Vol:28, ISSN:0272-989X, Pages:668-680

Kostopoulou O, 2008, Do GPs report diagnostic errors?, Family Practice, Vol:25, ISSN:0263-2136, Pages:1-2

Kostopoulou O, Delaney B, 2007, Confidential reporting of patient safety events in primary care: results from a multilevel classification of cognitive and system factors, Quality & Safety in Health Care, Vol:16, ISSN:1475-3898, Pages:95-100

Kostopoulou O, 2006, From cognition to the system: developing a multilevel taxonomy of patient safety in general practice, Ergonomics, Vol:49, ISSN:0014-0139, Pages:486-502

Kostopoulou O, Wildman M, 2004, Sources of variability in uncertain medical decisions in the ICU: a process tracing study, Quality & Safety in Health Care, Vol:13, ISSN:1475-3898, Pages:272-280

Greenhalgh T, Kostopoulou O, Harries C, 2004, Making decisions about benefits and harms of medicines, British Medical Journal, Vol:329, ISSN:1756-1833, Pages:47-50B

Kostopoulou O, Duncan KD, 2001, Abstract and reduced-context representations in fault-finding training, Ergonomics, Vol:44, ISSN:0014-0139, Pages:175-201

Kostopoulou O, Shepherd A, 2000, Fragmentation of treatment and the potential for human error in neonatal intensive care., Top Health Inf Manage, Vol:20, ISSN:1065-0989, Pages:78-92

Kostopoulou O, Brickley MR, Shepherd JP, et al., 2000, Perceived risk of future pathology associated with pathology-free third molars: a comparison of oral and maxillofacial surgeons and family dentists, British Dental Journal, Vol:188, ISSN:0007-0610, Pages:28-31

Kostopoulou O, Brickley MR, Shepherd JP, et al., 1998, Intra-observer reliability regarding removal of asymptomatic third molars, British Dental Journal, Vol:184, ISSN:0007-0610, Pages:557-559


Kostopoulou O, 2009, Diagnostic errors: psychological theories and research implications., Health Care Errors and Patient Safety, Editor(s): Hurwitz, Sheikh, Oxford, Blackwell, ISBN:9781444360318

Harries C, Kostopoulou O, 2005, Measuring and Modelling Clinical Decision Making, Handbook of Health Research Methods: Investigation, Measurement and Analysis, Editor(s): Bowling, Ebrahim, Open University Press, Pages:331-361


Kostopoulou O, Sirota M, Round T, et al., 2014, The role of information gathering and physician experience in detecting early presentations of cancer in primary care, WILEY-BLACKWELL, Pages:29-29, ISSN:0961-5423

Hagmayer Y, Kostopoulou O, 2013, A probabilistic constraint satisfaction model of information distortion in diagnostic reasoning., Cooperative Minds: Social Interaction and Group Dynamics, Cognitive Science Society, Austin, TX

More Publications