Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-23T06:48:46.368Z Has data issue: false hasContentIssue false

Ineffectiveness of cognitive forcing strategies to reduce biases in diagnostic reasoning: acontrolled trial

Published online by Cambridge University Press:  04 March 2015

Jonathan Sherbino*
Division of Emergency Medicine, Department of Medicine, McMaster University, Hamilton, ON
Kulamakan Kulasegaram
Program for Educational Research and Development, McMaster University, Hamilton, ON
Elizabeth Howey
Program for Educational Research and Development, McMaster University, Hamilton, ON
Geoffrey Norman
Program for Educational Research and Development, McMaster University, Hamilton, ON
McMaster Clinic 2nd Floor, Hamilton General Hospital Site, 237 Barton Street East, Hamilton, ONL8L 2X2;


Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Cognitive forcing strategies (CFS)may reduce error arising from cognitive biases. This is the first experimental test to determine the effect of CFS training in medical students.


Students were allocated to CFS training or control during a 4-week emergency medicine rotation (n = 191). At the end of the rotation examination, students were tested using computer-based cases. Application of CFS could enable reduction of diagnostic error, as evidenced by identifying multiple correct diagnoses for the two cases prone to search satisficing bias (SSB) and uncommon diagnoses for the two cases prone to availability bias (AB). Two “false positive” cases were included to test for possible “oversearching.”


There were 145 students in the intervention and 46 in the control group. For the SSB cases, 52% of students with CFS training and 48% in the control group initiated a search for the second diagnosis (χ2 = 0.13, df = 1, p = 0.91). More than half (54%) correctly identified the second diagnosis in the CFS group, and 48% identified it in the control group. The difference was not significant (χ2 = 2.25, df = 1, p = 0.13). For the second diagnosis in the false positive cases, 64% of the CFS group and 77% of the control group incorrectly identified it. There were no significant differences between groups (χ2 = 2.38, df = 1, p = 0.12). In the AB cases, only 45% in each group identified the uncommon correct diagnosis (χ2 = 0.001, df = 1, p = 0.98).


The educational interventions suggested by experts in clinical reasoning and employed in our study to teach CFS failed to show any reduction in diagnostic error by novices.

Original Research • Recherche originale
Copyright © Canadian Association of Emergency Physicians 2014



1.Graber, M, Franklin, N, Gordon, R.Diagnostic error in internal medicine. Arch Intern Med 2005;165:1493–9, doi:10.1001/archinte.165.13.1493.CrossRefGoogle ScholarPubMed
2.Kohn, LT, Corrigan, JM, Donaldson, MS, editors. To err is human. Building a safer health system. Washington (DC): National Academy Press; 1999.Google Scholar
3.Kuhn, GJ.Diagnostic errors. Acad Emerg Med 2002;9:740–50, doi:10.1111/j.1553-2712.2002.tb02155.x.Google Scholar
4.Agency for Healthcare Research and Quality. Medical errors: the scope of the problem. Available at: (accessed July 1, 2008).Google Scholar
5.Blendon, RJ, DesRoches, CM, Brodie, M.Views of practicing physicians and the public on medical errors. N Engl J Med 2002;347:1933–9, doi:10.1056/NEJMsa022151.CrossRefGoogle ScholarPubMed
6.Leape, LL, Brennan, TA, Laird, N, et al. The nature of adverse events in hospitalized patients. Results of the Harvard Medical Practice Study II. N Engl J Med 1991;324:377–84, doi:10.1056/NEJM199102073240605.Google Scholar
7.Croskerry, P.Cognitive forcing strategies in clinical decisionmaking. Ann Emerg Med 2003;41:110–20, doi:10.1067/mem.2003.22.CrossRefGoogle ScholarPubMed
8.Croskerry, P.Cognitive forcing strategies in emergency medicine. Emerg Med J 2002;19:A9.Google Scholar
9.Croskerry, P.Critical thinking and decision making: avoiding the perils of thin-slicing. Ann Emerg Med 2006;6:720–3, doi:10.1016/j.annemergmed.2006.03.030.CrossRefGoogle Scholar
10.Redelmeier, D.The cognitive psychology of missed diagnoses. Ann Intern Med 2005;142:115–20, doi:10.7326/0003-4819-142-2-200501180-00010.Google Scholar
11.Kahnemann, D, Slovik, P, Tversky, A, editors. Judgment under uncertainty: heuristics and biases. New York: Cambridge University Press; 1982.CrossRefGoogle Scholar
12.Croskerry, P.The importance of cognitive errors in diagnosis and strategies to minimize them. Acad Med 2003;78:775–80.CrossRefGoogle Scholar
13.Elstein, AS.Heuristics and biases: selected errors in clinical reasoning. Acad Med 1999;74:791–4, doi:10.1097/00001888-199907000-00012.CrossRefGoogle ScholarPubMed
14.Singh, H, Petersen, LA, Thomas, EJ.Understanding diagnostic errors in medicine: a lesson from aviation. Qual Saf Health Care 2006;15:159–64, doi:10.1136/qshc.2005.016444.Google Scholar
15.Sherbino, J, Yip, S, Dore, KL, et al. The effectiveness of cognitive forcing strategies to decrease diagnostic error: anexploratory study. Teach Learn Med 2011;23:7884, doi:10.1080/10401334.2011.536897.Google Scholar
16.Ark, TK, Brooks, LR, Eva, KW.The benefits of flexibility: the pedagogical value of instructions to adopt multifaceted diagnostic reasoning strategies. Med Educ 2007;41:281–7, doi:10.1111/j.1365-2929.2007.02688.x.CrossRefGoogle ScholarPubMed
17.Kulatunga-Moruzi, C, Brooks, LR, Norman, GR.Coordination of analytic and similarity-based processing strategies and expertise in dermatological diagnosis. Teach Learn Med 2001;13:110–6, doi:10.1207/S15328015TLM1302_6.Google Scholar
18.Evans, JSBT.Dual-processing accounts of reasoning, judgment, and social cognition. Annu Rev Psychol 2008;59:255–78, doi:10.1146/annurev.psych.59.103006.093629.CrossRefGoogle ScholarPubMed
19.Van Merriënboer, JJG, Sweller, J.Cognitive load theory in health professional education: design principles and strategies. Med Educ 2010;44:8593, doi:10.1111/j.1365-2923.2009.03498.x.Google Scholar
20.Mamede, S, Schmidt, HG, Rikers, RM, et al. Breaking down automaticity: case ambiguity and the shift to reflective approaches in clinical reasoning. Med Educ 2007;41:1185–92, doi:10.1111/j.1365-2923.2007.02921.x.CrossRefGoogle ScholarPubMed
21.Mamede, S, Schmidt, HG, Penaforte, JC.Effects of reflective practice on the accuracy of medical diagnoses. Med Educ 2008;42:468–75, doi:10.1111/j.1365-2923.2008.03030.x.CrossRefGoogle ScholarPubMed
22.Ilgen, JS, Bowen, JL, Yarris, LM, et al. Adjusting our lens: can developmental differences in diagnostic reasoning be harnessed to improve health professional and trainee assessment? Acad Emerg Med 2011;18 Suppl 2:S7986, doi:10.1111/j.1553-2712.2011.01182.x.Google Scholar
23.Sherbino, J, Dore, KL, Wood, TJ, et al. The relationship between response time and diagnostic accuracy. Acad Med 2012;87:785–91.CrossRefGoogle ScholarPubMed
24.Norman, GR, Brooks, LR, Colle, CL, et al. The benefit of diagnostic hypotheses in clinical reasoning: experimental study of an instructional intervention for forward and backward reasoning. Cogn Instruct 1999;17:433–48, doi:10.1207/S1532690XCI1704_3.Google Scholar
25.Ark, T, Brooks, LR, Eva, KW.Giving learners the best of both worlds: do clinical teachers need to guard against teaching pattern recognition to novices? Acad Med 2006;81: 405–9, doi:10.1097/00001888-200604000-00017.CrossRefGoogle ScholarPubMed
26.Eva, KW, Hatala, RM, Leblanc, VR, Brooks, LR.Teaching from the clinical reasoning literature: combined reasoning strategies help novice diagnosticians overcome misleading information. Med Educ 2007;41:1152–8, doi:10.1111/j.1365-2923.2007.02923.x.Google Scholar
27.Coderre, S, Wright, B, McLaughlin, K.To think is good: querying an initial hypothesis reduces diagnostic error in medical students. Acad Med 2010;85:1125–9, doi:10.1097/ACM.0b013e3181e1b229.CrossRefGoogle ScholarPubMed
28.Eva, KW, Cunnington, JP.The difficulty with experience: does practice increase susceptibility to premature closure? J Contin Educ Health Prof 2006;26:192–8, doi:10.1002/chp.69.Google Scholar