title: Determinants of participation in an epidemiological study of preterm delivery.
abstract: We describe the study design and patterns of participation for a cohort study of preterm delivery, focused on genital tract infections, nutrition, tobacco use, illicit drugs and psychosocial stress. Women are recruited at 24-29 weeks' gestation from prenatal clinics at a teaching hospital and a county health department. We recruited 57% of the first 1843 eligible women; 29% refused and 8% could not be contacted. White women were somewhat more likely to participate than African-American women (61% vs. 54% respectively). More notable differences were found comparing teaching hospital and health department clinics (71% vs. 47% participation respectively), with the health department clinic having a greater proportion refuse (24% vs. 33%) and more women who could not be contacted (4% vs. 11%). Participation was affected only minimally by day or timing of recruitment, but inability to contact diminished substantially as the study continued (13-0%). Refusals were largely unrelated to patient attributes. Lower education predicted inability to contact. Risk of preterm delivery was 14% among recruited women, 10% among women who refused, and 15% among women whom we were not able to contact, demonstrating that, overall, risk status was not lower among recruited women.
authors.affiliation: Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill 27599-7400, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Savitz
authors.forename: N
authors.initials: N
authors.lastname: Dole
authors.forename: J
authors.initials: J
authors.lastname: Williams
authors.forename: J M
authors.initials: JM
authors.lastname: Thorp
authors.forename: T
authors.initials: T
authors.lastname: McDonald
authors.forename: A C
authors.initials: AC
authors.lastname: Carter
authors.forename: B
authors.initials: B
authors.lastname: Eucker
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D009657:North Carolina / Q000453:epidemiology; D007752:Obstetric Labor, Premature / Q000453:epidemiology*; D018579:Patient Selection; D011247:Pregnancy; D011446:Prospective Studies; D012107:Research Design; D012959:Socioeconomic Factors