Subgroup Variation in Diagnostic Test Evaluation
Authors: Arthur T. Evans
Journal: Annals of Internal Medicine (2003)

Letters15 April 2003Subgroup Variation in Diagnostic Test EvaluationArthur T. Evans, MD, MPHArthur T. Evans, MD, MPHCook County Hospital and Rush Medical College; Chicago, IL 60612 (Evans)Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-138-8-200304150-00023 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail TO THE EDITOR:The article by Mulherin and Miller on subgroup variation in diagnostic test evaluation is an important contribution (1). Although test performance may truly vary across subgroups, this variation might also be spuriousreference test bias masquerading as spectrum effect.Whenever the reference testthe gold standardis imperfect (a common occurrence), test characteristics (sensitivity, specificity, and likelihood ratios) will vary across subgroups that differ in prevalence of disease (2-4). Sensitivity will spuriously appear higher and specificity will spuriously appear lower in the patient subgroups with the higher prevalence, merely because the reference test is imperfect. This pattern assumes that the ...References1. Mulherin SA, Miller WC. Spectrum bias or spectrum effect? Subgroup variation in diagnostic test evaluation. Ann Intern Med. 2002;137:598-602. [PMID: 12353947] LinkGoogle Scholar2. Brenner H, Gefeller O. Variation of sensitivity, specificity, likelihood ratios and predictive values with disease prevalence. Stat Med. 1997;16:981-91. [PMID: 9160493] CrossrefMedlineGoogle Scholar3. Boyko EJ, Alderman BW, Baron AE. Reference test errors bias the evaluation of diagnostic tests for ischemic heart disease. J Gen Intern Med. 1988;3:476-81. [PMID: 3049969] CrossrefMedlineGoogle Scholar4. Miller WC. Bias in discrepant analysis: when two wrongs don't make a right. J Clin Epidemiol. 1998;51:219-31. [PMID: 9495687] CrossrefMedlineGoogle Scholar5. Lachs MS, Nachamkin I, Edelstein PH, Goldman J, Feinstein AR, Schwartz JS. Spectrum bias in the evaluation of diagnostic tests: lessons from the rapid dipstick test for urinary tract infection. Ann Intern Med. 1992;117:135-40. [PMID: 1605428] LinkGoogle Scholar Author, Article, and Disclosure InformationAffiliations: Cook County Hospital and Rush Medical College; Chicago, IL 60612 (Evans) PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetailsSee AlsoSpectrum Bias or Spectrum Effect? Subgroup Variation in Diagnostic Test Evaluation Stephanie A. Mulherin and William C. Miller Subgroup Variation in Diagnostic Test Evaluation Ronald R. Scobbo Subgroup Variation in Diagnostic Test Evaluation Stephanie A. Mulherin and William C. Miller Metrics Cited byDiagnostic test accuracy may vary with prevalence: implications for evidence-based diagnosis 15 April 2003Volume 138, Issue 8Page: 686KeywordsAge groupsChlamydia trachomatisEnzyme immunoassayLigasesLikelihood ratioSpecificityUrine ePublished: 15 April 2003 Issue Published: 15 April 2003 Copyright & PermissionsCopyright © 2003 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...