title: Matching, an appealing method to avoid confounding?
abstract: Matching is a technique used to avoid confounding in a study design. In a cohort study this is done by ensuring an equal distribution among exposed and unexposed of the variables believed to be confounding. In a matched case-control study, a case, affected by the disease, is matched with one or more individuals not affected by the disease, the controls. Because in a matched case-control study case and control group become too similar not only in the distribution of the confounder but also in the distribution of the exposure, one finds a lower effect estimate (odds ratio closer to 1). A matched case-control study requires statistical analysis to correct for this phenomenon. Nonetheless, a matched case-control study is suitable for confounders that are difficult to measure.
authors.affiliation: Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, The Netherlands. M.A.de_Graaf @ LUMC.nl
authors.forename: Michiel A
authors.initials: MA
authors.lastname: de Graaf
authors.forename: Kitty J
authors.initials: KJ
authors.lastname: Jager
authors.forename: Carmine
authors.initials: C
authors.lastname: Zoccali
authors.forename: Friedo W
authors.initials: FW
authors.lastname: Dekker
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D008297:Male; D012107:Research Design; D012737:Sex Factors