Probability samples of area births versus clinic populations for reproductive epidemiology studies.

Journal Article (Journal Article)

Studies of pregnancy outcome are generally based either on geographically defined populations, often from birth records, or on clinic or hospital populations. We compared women recruited into a clinic-based study, the Pregnancy, Infection, and Nutrition (PIN) Study, with women who resided in the geographical area of the study (Alamance, Orange, and Wake Counties in North Carolina) and gave birth over the corresponding time period (1996-2000). Clinic participants were more likely to be Black, younger, have lower education, be unmarried, have a more frequent history of adverse pregnancy outcome, obtain prenatal care later, and smoke more cigarettes. Despite that profile, the proportion of clinic participants delivering preterm was somewhat lower than among area women overall (10.8% vs. 11.3%). Black/White risk ratios for preterm birth were markedly different for area (1.6) vs. clinic women (1.1), whereas other predictors were similar. Patterns may differ across groups for many reasons, including self-selection of clinics and varying clinical practices.

Full Text

Duke Authors

Cited Authors

  • Savitz, DA; Dole, N; Kaczor, D; Herring, AH; Siega-Riz, AM; Kaufman, J; Thorp, JM

Published Date

  • July 2005

Published In

Volume / Issue

  • 19 / 4

Start / End Page

  • 315 - 322

PubMed ID

  • 15958154

Electronic International Standard Serial Number (EISSN)

  • 1365-3016

International Standard Serial Number (ISSN)

  • 0269-5022

Digital Object Identifier (DOI)

  • 10.1111/j.1365-3016.2005.00649.x


  • eng