Applying calculations to clinical medicine requires nuance: author's reply

• Published in: Journal of clinical epidemiology Vol. 152; pp. 328 - 329
• Main Author: Uy, Elenore Judy B.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2022; Elsevier Limited
• Subjects: Clinical Medicine; Decision making; Diagnosis; Diagnostic systems; Diagnostic tests; Health services; Humans; Mathematical analysis; Medicine; Probability
• ISSN: 0895-4356; 1878-5921
• DOI: 10.1016/j.jclinepi.2022.08.009

Shared decision-making in diagnosis is therefore involved not just in treatment decisions but also the approach to diagnostic testing [3]. Once set, however, these decision thresholds become the objective basis for deciding whether or not the post-test probability from a round of testing would result in (1) definitively ruling out the disease (i.e., post-test probability has crossed the diagnostic threshold), (2) committing to the diagnosis and proceeding to implement treatment (i.e., post-test probability has crossed the therapeutic threshold), or (3) doing further tests for the disease under consideration (i.e., post-test probability is still within the testing range).2 Starting the calculation with probability (risk) rather than odds may be inconsequential when prevalence is low but would not work at higher prevalence rates The example provided in Section 5 of the paper is indeed a simplified example. The ability to estimate pretest probability is therefore an important starting point for prioritizing which differential diagnoses to test for, and subsequently, the type of diagnostic test to use [2].