Medical Decision Making and Medical Problem Solving are two main approaches used to describe the cognitive processes underlying clinical diagnosis.(1) This distinction is the result of historical factors. A diagnosis is a statement about what disease someone has (http://www.macmillandictionary.com) based on symptoms (subjectively) and signs (objectively).(2) Medical decision making (MDM) models are concerned with diagnostic reasoning as an opinion revision process.(3) They make use of Bayes’ theorem, likelihood ratios, prior and posterior odds, thresholds, schemes and decision trees to arrive at the best diagnostic and therapeutic decisions. (1;3-7) These mathematical models, incorporating clinical epidemiological data, are related to the concept of evidence-based medicine.

Research into medical problem solving regards diagnostic reasoning as a process of generating and testing hypotheses.(3;8;9) Experienced physicians immediately understand a patient’s problem in diagnostic terms based on only a few relevant signs and symptoms. (8;10) Afterwards a deliberate verification and testing of these hypotheses is necessary. In more complex cases when a diagnosis is not readily available clinicians rely on their medical knowledge by listing patient features, weighing them up, and mapping them to the signs and symptoms known to be associated with certain diseases.(1) Alternatively, they can engage in causal reasoning with biomedical knowledge to bridge the gaps between the elements of the clinical picture.(11;12)

(1) Stolper CF, Van de Wiel M, Van Royen P, Van Bokhoven MA, Van der Weijden T, Dinant GJ. Gut feelings as a third track in general practitioners’ diagnostic reasoning. J Gen Intern Med 2011;26(2):197-203.

(2) Aronowitz RA. When do symptoms become a disease? Ann Intern Med 2001 May 1;134(9 Pt 2):803-8.

(3) Elstein AS, Schwarz A. Clinical problem solving and diagnostic decision making: a selective review of the cognitive literature. BMJ 2002 Mar 23;324(7339):729-32.

(4) Chapman GB, Sonnenberg F. Decision making in health care: theory, psychology, and applications. New York: Cambridge University Press; 2000.

(5) Sackett DL, Haynes RB, Guyatt GH, Tugwell P. Clinical epidemiology: a basic science for clinical medicine. 2 ed. Boston: Little, Brown; 1991.

(6) Richardson WS, Wilson MC, Guyatt GH, Cook DJ, Nishikawa J. Users’ guides to the medical literature: XV. How to use an article about disease probability for differential diagnosis. Evidence-Based Medicine Working Group. JAMA 1999 Apr 7;281(13):1214-9.

(7) Pauker SG, Kassirer JP. The threshold approach to clinical decision making. N Engl J Med 1980 May 15;302(20):1109-17.

(8) Elstein AS, Shulman L, Sprafka S. Medical Problem Solving: an analysis of clinical reasoning. Cambridge, Mass.: Harvard University Press; 1978.

(9) Neufeld VR, Norman GR, Feightner JW, Barrows HS. Clinical problem-solving by medical students: a cross-sectional and longitudinal analysis. Med Educ 1981 Sep;15(5):315-22.

(10) Norman GR, Eva K, Brooks LR, Hamstra S. Expertise in Medicine and Surgery. In: Ericsson KA, Charness N, Feltovich PJ, Hoffman RR, editors. The Cambridge Handbook of Expertise and Expert Performance.New York: Cambridge University Press; 2006. p. 339-54.

(11) Norman GR, Trott AD, Brooks LR, Smith EKM. Cognitive differences in clinical reasoning related to postgraduate training. Teaching and Learning in Medicine 1994;6(2):114-20.

(12) Patel VL, Groen GJ, Arocha JF. Medical expertise as a function of task difficulty. Mem Cognit 1990 Jul;18(4):394-406.