title: [Confidence intervals and p-values in urology: interpretation and misinterpretation].
abstract: Confidence intervals and p-values are widely used in the urological literature to describe and interpret outcomes. However, several readers, authors and reviewers are unfamiliar with the true interpretation of these values. P-values determine statistical significance of data. Confidence intervals characterize a range of values in which the true effect size is suggested to be with a given degree of certainty. An independent but complementary interpretation of both values is important in studies with and without statistical significance. Based on a clinical case scenario this article discusses the interpretation as well as common pitfalls in interpretation of p-values and confidence intervals. An accurate assessment of these statistical cornerstones is fundamental for a correct interpretation of the urological literature and thus important aspects of evidence-based urology.
authors.affiliation: Klinik und Poliklinik für Urologie, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Deutschland. mrink@uke.uni-hamburg.de
authors.forename: M
authors.initials: M
authors.lastname: Rink
authors.forename: L A
authors.initials: LA
authors.lastname: Kluth
authors.forename: S F
authors.initials: SF
authors.lastname: Shariat
authors.forename: R
authors.initials: R
authors.lastname: Dahlem
authors.forename: M
authors.initials: M
authors.lastname: Fisch
authors.forename: P
authors.initials: P
authors.lastname: Dahm
mesh_terms: D016001:Confidence Intervals; D003627:Data Interpretation, Statistical; D019317:Evidence-Based Medicine / Q000706:statistics & numerical data*; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000379:methods*; D016896:Treatment Outcome; D014570:Urologic Diseases / Q000453:epidemiology* / Q000628:therapy*