![]() Both sensitivity and specificity are essential when describing the value of selected tests and measures used during diagnosis. Specificity is calculated using the formula: Sp = True negatives/(True negatives + False positives). Specificity, or the true negative rate, is defined as the proportion of patients who do not have the disease that the test identifies as negative. Sensitivity, or the true positive rate, is defined as the proportion of patients who have the disease that the test identifies as positive and is calculated using the formula: Sn = True positives/(True positives + False negatives). The purpose of this clinimetrics corner titled “Beyond SPIN and SNOUT: Considerations with Dichotomous Tests During Assessment of Diagnostic Accuracy” is to discuss the limitations of these shortcuts for diagnostic accuracy. Unfortunately, using sensitivity or specificity independently to confirm a diagnosis may lead to error. Specific tests are advocated as highly sensitive or specific, purportedly rendering that test effective at either ruling out (if sensitive) or ruling in (if specific) a given diagnosis. In an effort to rule in or rule out a disease or condition, clinicians often use one or multiple tests to confirm or refute a hypothesis. Last, the quality of a diagnostic accuracy study can affect the generalizibility of the results to practice environments. Second, appropriate power must be considered when evaluating each study. ![]() First, sensitivity, specificity, and other estimates of the diagnostic accuracy of dichotomous physical examination tests should be viewed as estimates with confidence when those estimates are expressed as confidence intervals. Using examples from diagnostic accuracy studies and a review of pertinent literature, this clinimetrics corner outlines additional considerations for clinicians when consuming research in this area. In an effort to improve the clinical utility of diagnostic accuracy calculations, researchers have promoted the use of the mnemonics SpPIn (if specificity is high, a positive test rules in pathology) and SnNOut (if se nsitivity is high, a negative test rules out pathology). Paramount to efficient and effective care is the determination of an accurate diagnosis that leads to the proper referral and/or intervention. ![]()
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