title: [Tools for the evaluation of diagnostic techniques].
abstract: This presentation focuses on evaluation of the diagnostic value of clinical findings, laboratory test results and data provided by diagnostic technologies including imaging techniques. A sign S or indicant of a disease D is a datum which is more frequent (more likely) in patients with the disease D than in subjects free of the disease D. The ratio of these two conditional probabilities is the likelihood ratio or Bayes factor of S for D. For a given test T, the number of likelihood ratios is equal to the number of different result patterns obtained with test T. The likelihood ratio reflects the role of the test result in the predictive value, i.e., the likelihood that the disease is present given the test result observed. The likelihood ratio is the tool of choice for evaluating the diagnostic value of a test. The method proposed by Spiegelhalter and Knill-Jones is based on the likelihood ratio. Evaluation of an imaging technique rests on the characteristics of the "image-physician" combination. The rating method can be used to analyze Receiver Operating Characteristic curves in view of assessing either the imaging technique or the physician's diagnostic skills.
authors.affiliation: Centre de Pédiatrie, Tours, France.
authors.forename: B
authors.initials: B
authors.lastname: Grenier
mesh_terms: D019411:Clinical Laboratory Techniques; D003933:Diagnosis; D003952:Diagnostic Imaging; D005069:Evaluation Studies as Topic; D005602:France; D006801:Humans; D007827:Laryngitis / Q000175:diagnosis; D008722:Methods; D012372:ROC Curve; D013290:Streptococcal Infections / Q000175:diagnosis; D011795:Surveys and Questionnaires
vernacular_title: Les outils de l'évaluation des techniques diagnostiques.