title: Biases in observational studies of the effect of prenatal treatment for congenital toxoplasmosis.
abstract: The paper reviews methodological difficulties that arise when using observational studies to evaluate the effect of prenatal screening and treatment. The principle of each difficulty is described and then illustrated by a clinical example of toxoplasmosis in pregnancy and its consequences. Methods to deal with these difficulties are described. Given the limitations of existing observational studies and lack of randomised controlled trials, a systematic review of cohort studies offers the best approach for exploring potential biases.
authors.affiliation: INSERM U593, Institut de Santé Publique, d'Epidémiologie et de Développement (ISPED), Université Bordeaux 2-Victor Segalen, Bordeaux, France. rodolphe.thiebaut@isped.u-bordeaux2.fr
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Thiébaut
authors.forename: Valériane
authors.initials: V
authors.lastname: Leroy
authors.forename: Ahmadou
authors.initials: A
authors.lastname: Alioum
authors.forename: Christine
authors.initials: C
authors.lastname: Binquet
authors.forename: Gwendoline
authors.initials: G
authors.lastname: Poizat
authors.forename: L Rachid
authors.initials: LR
authors.lastname: Salmi
authors.forename: Luuk
authors.initials: L
authors.lastname: Gras
authors.forename: Roger
authors.initials: R
authors.lastname: Salamon
authors.forename: Ruth
authors.initials: R
authors.lastname: Gilbert
authors.forename: Geneviève
authors.initials: G
authors.lastname: Chêne
mesh_terms: D000328:Adult; D015982:Bias; D036262:Empirical Research; D005260:Female; D005865:Gestational Age; D006801:Humans; D015588:Observer Variation; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000188:drug therapy* / Q000453:epidemiology; D011295:Prenatal Care; D015983:Selection Bias; D014125:Toxoplasmosis, Congenital / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control