title: An international case-control study on hypospadias. The problem with variability and the beauty of diversity.
abstract: The paper describes problems and advantages in an international cooperative study of a case-control design, aimed at investigating the possible association between exogenous hormones and hypospadias. The varying degrees of the ascertainment of specific exposures and risk factors, in spite of the use of a standardized questionnaire is illustrated. Definite support for the existence of recall or interviewer bias is presented. On the other hand, the multipopulation design offers possibilities to make use of the diversity of the populations: differences in reproductive patterns and in specific exposures such as drug use, smoking and maternal occupation.
authors.affiliation: Department of Embryology, University of Lund, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Källén
authors.forename: E E
authors.initials: EE
authors.lastname: Castilla
authors.forename: E
authors.initials: E
authors.lastname: Robert
authors.forename: P A
authors.initials: PA
authors.lastname: Lancaster
authors.forename: M
authors.initials: M
authors.lastname: Kringelbach
authors.forename: O
authors.initials: O
authors.lastname: Mutchinick
authors.forename: M L
authors.initials: ML
authors.lastname: Martínez-Frias
authors.forename: P
authors.initials: P
authors.lastname: Mastroiacovo
mesh_terms: D015982:Bias; D016022:Case-Control Studies; D003625:Data Collection; D005260:Female; D006801:Humans; D007021:Hypospadias / Q000453:epidemiology*; D007391:International Cooperation; D008297:Male; D011939:Mental Recall; D010865:Pilot Projects; D011247:Pregnancy; D012307:Risk Factors; D011795:Surveys and Questionnaires