It is well documented that human beings are for the most part noncritical thinkers and that we are prone to deductive and inductive errors in reasoning (i.e., judgment errors). Additionally, the cognitive limitation of human working memory leads us to access simpler rather than more complex cognitive or problem-solving strategies (i.e., shortcuts in reasoning). In actuality, it is likely the combination of judgment errors and reliance on shortcuts in reasoning (e.g., heuristics) that leads to most errors in clinical reasoning. Finally, errors will vary based on the difficulty of the patient case, knowledge of content and context, strategy selection, and integration and interpretation of pertinent patient information.
100. What is deductive reasoning?
Deductive reasoning involves reaching a conclusion based on evidence (i.e., deductive reasoning combines two or more pieces of evidence to reach a conclusion).
101. What are examples of deductive reasoning errors?
Illogical or poor reasoning, persistence of beliefs despite empirical data to the contrary, rationalizing, justifying, and using biases and heuristics to assess information are examples of deductive reasoning errors.
102. What is inductive reasoning?
Inductive reasoning uses specific pieces of evidence (i.e., more than one example) to draw conclusions that are probably, but not necessarily, true (e.g., generalizations, cause and effect, and analogies).
103. What are examples of inductive reasoning errors?
Examples include overconfidence in validity of beliefs, confusion of opinion or anecdotal evidence with truth, overestimation of knowledge, and basing a decision on personal interests.
104. What is iterative hypothesis testing?
Iterative hypothesis testing, as described by Kasper and Harrison, is a process used by medical practitioners to increase the efficiency of the interview process. During this process interview questions are used to confirm or refute the evolving diagnostic hypothesis. Iterative hypothesis testing uses specific questions to probe patient answers. Iterative hypothesis testing does not replace
a systematic, thorough, and complete history of present illness, past medical history, review of systems, family history, and the physical examination. Iterative hypothesis testing represents a pattern of application of inductive and deductive reasoning.
105. Give an example of iterative hypothesis testing based on a patient’s perception of illness.
The patient presents with a referral that states: “Lumbar pain, Evaluate and Treat.” Therapist:
“What are you here for today?” Patient: “I have a pinched nerve in my back.” Therapist: “Who was the doctor that diagnosed you with this condition?” Patient: “It was not my doctor.” Therapist: “I am not certain if I understand; how did you determine that you have a pinched nerve in your back?” Patient: “About a year ago my neighbor had the same pain that I am having and he was diagnosed with a pinched nerve in his back.” In this example if the therapist did not test the hypothesis, a serious error could have occurred.
106. List common errors or biases in clinical reasoning and a potential consequence of the error or bias.
Error or Bias Possible Consequences
Adding pragmatic inferences Making diagnostic assumptions that result in misdiagnoses or faulty clinical decisions Confirmation bias (e.g., emphasizing or validating Failure to identify or address competing information that supports clinician’s favored diagnoses and limiting examination to tests and hypotheses while negating information that does measures that confirm suspected diagnosis
not) while ignoring evidence and testing that might
eliminate diagnosis
Confusing covariance with causality Presuming that two or more factors are causally related when two factors have been found to covary
Confusions between deductive and inductive logic Deductive reasoning errors or drawing conclusions that go beyond the information contained in premises (e.g., correct: if A then B, A therefore B; incorrect: if A then B, therefore if B then A); inductive reasoning errors or
generalizations based on specific observations that are not based on deductive reasoning (e.g., all A are B ≠all B are A)
Considering too few diagnoses (e.g., hypotheses) Artificially or prematurely limiting number of plausible diagnoses
Considering too few interventions Choosing same intervention option when there are additional and alternative options available Errors in detecting variance Making a judgment about relationship of two
factors without understanding how two factors covary with one another
Failure to sample enough information Basing clinical decisions on generalizations and limited data and discontinuing search for
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Bibliogaphy
Addison RG: Chronic pain syndrome,Am J Med 77:54-58, 1984.
American Physical Therapy Association: Guide to physical therapist practice: second edition,Phys Ther 81:9-746, 2001.
Bogduk N, Twomey LT:Clinical anatomy of the lumbar spine,New York, 1987, Churchill Livingstone.
Bordage G: Elaborated knowledge: a key to successful diagnostic thinking,Acad Med 69:883-885, 1994.
Boyling JD, Palastanga N, Grieve GP:Grieve’s modern manual therapy: the vertebral column,ed 2, New York, 1994, Churchill Livingstone.
Edwards I et al: Clinical reasoning strategies in physical therapy,Phys Ther 84:312-330, 2004 (discussion 331-335).
Elstein AS: Heuristics and biases: selected errors in clinical reasoning,Acad Med 74:791-794, 1999.
Friedman MH et al: Medical student errors in making a diagnosis,Acad Med 73(10 suppl):S19-21, 1998.
Gamsa A, Vikis-Freibergs V: Psychological events are both risk factors in, and consequences of, chronic pain, Pain44:271-277, 1991.
Garfin SR et al: Spinal nerve root compression,Spine20:1810-1820, 1995.
Goodman CC, Snyder TEK:Differential diagnosis in physical therapy,ed 3, Philadelphia, 2000, WB Saunders.
Groves M, O’Rourke P, Alexander H: The clinical reasoning characteristics of diagnostic experts,Med Teach 25:308-313, 2003.
Higgs J, Jones MA:Clinical reasoning in the health professions,ed 2, Oxford, 2000, Butterworth-Heinemann.
Holloway PJ: Inductive vs deductive reasoning,Br Dent J 188:643-644, 2000.
Jarvik JG, Deyo RA: Diagnostic evaluation of low back pain with emphasis on imaging,Ann Intern Med 137:586-597, 2002.
Jarvis C:Physical examination & health assessment,ed 4, St Louis, 2004, WB Saunders.
Kasper DL, Harrison TR:Harrison’s’ principles of internal medicine,ed 16, New York, 2005, McGraw-Hill.
Kempainen RR, Migeon MB, Wolf FM: Understanding our mistakes: a primer on errors in clinical reasoning, Med Teach 25:177-181, 2003.
Mense S, Simons DG, Russell IJ:Muscle pain: understanding its nature, diagnosis, and treatment,Philadelphia, 2001, Lippincott Williams & Wilkins.
Moore KL, Dalley AF:Clinically oriented anatomy,ed 4, Philadelphia, 1999, Lippincott Williams & Wilkins.
Nissl J:Health guide A-Z: complete blood count (CBC) HTML; December 14, 2004; WebMDHealth (website):
http://my.webmd.com/hw/lab_tests/hw4260.asp. Accessed July 29, 2005.
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Error or Bias Possible Consequences
additional diagnoses after anticipated diagnosis is made
Faulty hypotheses testing Making clinical decisions based on illogical or faulty reasoning processes
Faulty or inadequate knowledge or skill base Making clinical decisions based on omissions that stem from lack of knowledge or omitting more beneficial interventions secondary to lack of knowledge or skill
Generating a diagnosis based on availability or Overestimating probability of a diagnosis and
recall generating false sense of frequency
Generating a diagnosis based on similarity or Neglecting prevalence of competing diagnoses pattern recognition
Generating a diagnosis based on patient Type of confirmation bias in which clinician perception of illness seeks to validate a self-reported patient
diagnosis
Round A: Introduction to clinical reasoning,J Eval Clin Pract 7:109-117, 2001.
Rubin E:Essential pathology,ed 3, Philadelphia, 2001, Lippincott.
Seidel HM et al:Mosby’s guide to physical examination,ed 4, St Louis, 1999, Mosby.
Wall PD, Melzack R, Bonica JJ:Textbook of pain,New York, 1984, Churchill Livingstone.
Willis WD, Jr: The pain system: the neural basis of nociceptive transmission in the mammalian nervous system,Pain Headache 8:1-346, 1985.