Résumé :
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[BDSP. Notice produite par INIST-CNRS R0xp999p. Diffusion soumise à autorisation]. To evaluate the representativeness of controls in an ongoing, population-based, case-control study of birth defects in 10 centers across the United States, researchers compared 1997-2003 birth certificate data linked to selected controls (n=6,681) and control participants (n=4,395) with those from their base populations (n=2,468,697). Researchers analyzed differences in population characteristics (e.g., percentage of births at>2,500 g) for each group. Compared with their base populations, control participants did not differ in distributions of maternal or paternal age, previous live births, maternal smoking, or diabetes, but they did differ in other maternal (i.e., race/ethnicity, education, entry into prenatal care) and infant (i.e., birth weight, gestational age, and plurality) characteristics. Differences in distributions of maternal, but not infant, characteristics were associated with participation by selected controls. Absolute differences in infant characteristics for the base population versus control participants were
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