TITLE

Quantifying how tests reduce diagnostic uncertainly

AUTHOR(S)
Coulthard, Malcolm G.
PUB. DATE
May 2007
SOURCE
Archives of Disease in Childhood;May2007, Vol. 92 Issue 5, p404
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background: Diagnostic tests are commonly evaluated from sensitivity and specificity, which are robust and independent of prevalence, but clinically not intuitive. Many clinicians prefer to use positive and negative predictive values (PPV and NPV), but they are frequently applied as if they are independent of prevalence, whereas this may make an important difference. Methods and results: We present graphs that allow easy reference to appropriate values and demonstrate that PPV and NPV are not independent of prevalence. PPV and NPV figures reflect the prior probability of the case having a positive diagnosis, estimated clinically from the history, examination and other results, as well as the impact of the test result. To avoid the common error of allowing for prior probability twice, and to interpret the impact of the test result alone, we present graphs of the proportionate reduction in uncertainty score (PRU), calculated from sensitivity, specificity and prevalence. These plots show the extent to which either a positive or negative test result affects the remaining degree of uncertainty about a diagnosis in either direction, according to likely clinical prevalence. Conclusions: PRU plots demonstrate the discriminatory value of tests more clearly than sensitivity and specificity from which they are derived, and should be published alongside them.
ACCESSION #
25374010

 

Related Articles

  • Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative. Bossuyt, Patrick M.; Reitsma, Johannes B.; Bruns, David E.; Gatsonis, Constantine A.; Glasziou, Paul P.; Irwig, Les M.; Lijmer, Jeroen G.; Moher, David; Rennie, Drummond; de Vet, Henrica C.W. // Annals of Clinical Biochemistry;Jul2003, Vol. 40 Issue 4, p357 

    Background: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in a study and to evaluate the generalizability of its results. Methods: The Standards for Reporting of Diagnostic Accuracy (STARD)...

  • Diagnostic Styles of Attending Pediatricians, Residents, and Nurses in Evaluating Febrile Children. Mccarthy, Paul L.; Cicchetti, Domenic V.; Stashwick, Carole A.; Spiesel, Sydney Z.; Dolan, Jr., Thomas F. // Clinical Pediatrics;Sep1982, Vol. 21 Issue 9, p534 

    In order to compare the diagnostic styles of attending pediatricians (A), residents (R), and nurses (N) in judging the degree of illness of a febrile child prior to physical examination, we studied the frequency with which they used 139 different history variables and 186 observation variables...

  • REVIEW The Use of “Overall Accuracy” to Evaluate the Validity of Screening or Diagnostic Tests. Alberg, Anthony J.; Park, Ji Wan; Hager, Brant W.; Brock, Malcolm V.; Diener-West, Marie // JGIM: Journal of General Internal Medicine;May2004 Part 1, Vol. 19 Issue 5, p460 

    Evaluations of screening or diagnostic tests sometimes incorporate measures of overall accuracy, diagnostic accuracy, or test efficiency. These terms refer to a single summary measurement calculated from 2 × 2 contingency tables that is the overall probability that a patient will be...

  • Making sense of diagnostic test likelihood ratios. Perera, Rafael; Heneghan, Carl // ACP Journal Club;Mar/Apr2007, Vol. 146 Issue 2, pA8 

    The article discusses the use of likelihood ratio (LR) in making diagnosis of a disease. LR summarizes information about the diagnostic test by combining information about the sensitivity and specificity. It tells how much a positive or negative result changes the likelihood that a patient would...

  • A NOVEL APPROACH TO DETERMINING BEST MEDICAL PRACTICES: LOOKING AT THE EVIDENCE. Tucker, John // Houston Journal of Health Law & Policy;2010, Vol. 10, p147 

    The article discusses the effective guidelines for best medical practices for the improvement of health care in the U.S. The guidelines incorporate clinician workflow and strategies for compliance in the guideline delivery system. The legislators will also play a key role in meeting the...

  • Physician Clinical Performance Assessment: Prospects and Barriers. Landon, Bruce E.; Normand, Sharon-Lise T.; Blumenthal, David; Daley, Jennifer // JAMA: Journal of the American Medical Association;9/3/2003, Vol. 290 Issue 9, p1183 

    The performance of physicians in their day-to-day clinical practices has become an area of intense public interest. Both patients and health care purchasers want more effective means of identifying excellent clinicians, and a variety of organizations are discussing and implementing plans for...

  • Who is leading guideline development in tissue viability? Coull, Alison // British Journal of Nursing;10/28/2004, Vol. 13 Issue 19, pS3 

    Discusses the development of evidence-based guidelines in tissue viability practice in Great Britain. Information on the best practice statements produced by the Nursing and Midwifery Practice Development Unit in Scotland; Impact of the presence of specialist nurses on tissue viability...

  • Transductive Machine Learning for Reliable Medical Diagnostics. Kukar, Matjaž; Grošelj, Ciril // Journal of Medical Systems;Feb2005, Vol. 29 Issue 1, p13 

    In the past decades Machine Learning tools have been successfully used in several medical diagnostic problems. While they often significantly outperform expert physicians (in terms of diagnostic accuracy, sensitivity, and specificity), they are mostly not being used in practice. One reason for...

  • Net Quiz:A brownish-red plaque in an adult. Harman, Mehmet; Akdeniz, Sedat; Balcı, Gökçen; Uzunlar, Ali Kemal // Indian Journal of Dermatology, Venereology & Leprology;Jan/Feb2009, Vol. 75 Issue 1, p121 

    The article presents the case of a 50-year old man who was presented to a clinic due to a slowly enlarging plague on his back. The wife told the clinicians that his husband had suffered a pimple-sized brownish lesion which continuously enlarging. After further examination using the patient's...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics