title: [The consistency and validity of a measurement in clinical pediatric research. Its definition, evaluation and interpretation].
abstract: In clinical pediatric research as in all research, one of the fundamental characteristics is the measurement of the studied features, either clinical, of laboratory or cabinet. A measurement must have two fundamental characteristics, for it to be considered as scientific: consistency and validity. The first one is centered on the variability of the measurement, which is due to the measuring instrument, to the subject or entity which is measured and to the individual or individuals who carry out the measuring, this is known as intra or interobserver variability, respectively. Validity is the fact of "actually" measuring what we want to measure. Both characteristics of measurement, are often mixed, between them and with other concepts, and this is the reason of not having a clear idea of what is the real meaning. This paper discusses the different terms that have been used for consistency and validity of a measurement. Also it points out how to assess consistency, from the validity, taking into account the measuring scale of the variables and the number of observers. Easy examples are used for the application of different formulas and for the interpretation of the results.
authors.affiliation: Departamento de Epidemiología Clínica, Hospital de Pediatría del Centro Médico Nacional Siglo XXI, México, D.F.
authors.forename: A
authors.initials: A
authors.lastname: Fajardo-Gutiérrez
authors.forename: L T
authors.initials: LT
authors.lastname: Yamamoto-Kimura
authors.forename: J
authors.initials: J
authors.lastname: Garduño-Espinoza
authors.forename: D M
authors.initials: DM
authors.lastname: Hernández-Hernández
authors.forename: M C
authors.initials: MC
authors.lastname: Martínez-García
mesh_terms: D010372:Pediatrics / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D012106:Research / Q000592:standards; D012107:Research Design; D013223:Statistics as Topic / Q000379:methods / Q000592:standards; D009626:Terminology as Topic
vernacular_title: Consistencia y validez de una medición en la investigaciíon clínica pediátrica. Definición, evaluación y su interpretación.