The Effect of Follow-Up on Limiting Non-Participation Bias in Genetic Epidemiologic Investigations

• Published in: European journal of epidemiology Vol. 14; no. 2; pp. 129 - 138
• Main Authors: Romitti, Paul A., Munger, Ronald G., Murray, Jeffrey C., Daack-Hirsch, Sandra, Hanson, James W., Burns, Trudy L.
• Format: Journal Article
• Language: English
• Published: Dordrecht Kluwer Academic Publishers 01.02.1998; Springer; Springer Nature B.V
• Subjects: Academic degrees; Adult; Bias; Biological and medical sciences; Birth defects; Blood; Blood specimen collection; Case-Control Studies; Child; Childbirth; Children; Children & youth; Cigarette smoking; Cleft Lip - blood; Cleft Lip - epidemiology; Cleft Lip - genetics; Cleft Palate - blood; Cleft Palate - epidemiology; Cleft Palate - genetics; Consent; Data collection; Demography; Environmental Exposure; Epidemiology; Families & family life; Family medical history; Fathers; Female; Follow-Up Studies; General aspects; Humans; Informed Consent; Investigations; Iowa - epidemiology; Male; Medical sciences; Methodology; Molecular Epidemiology; Mothers; Neonatal disorders; Odds Ratio; Parents; Participation; Patient Selection; Population; Population Surveillance; Postal Service; Pregnancy; Public health. Hygiene; Public health. Hygiene-occupational medicine; Reminder Systems; Smoking - epidemiology; Socioeconomic Factors; Surveillance; Telephone; Vitamins - therapeutic use; Iowa; Iowa City Iowa; United States > US; Utah; Human; Participation; Methodology; Genetics; Methodological bias; Case control study; Epidemiology; Congenital disease; Public health
• ISSN: 0393-2990; 1573-7284
• DOI: 10.1023/a:1007406313703

The use of a comprehensive follow-up strategy to limit non-participation bias was evaluated in a population-based case-control study of orofacial clefts. Birth parents were requested to provide exposure data, and index children and parents were asked to provide blood specimens. Follow-up included telephone or postal reminders every two weeks for up to three months. Consent to participate was received from 281 (76.6%) case mothers and 246 (72.4%) case fathers. The corresponding totals for controls were 279 (54.7%) and 245 (49.8%). Evaluation of participation rates by intensity of follow-up showed that 23% of case and 18% of control families consented without reminders (first stage); 81% of cases and 83% of controls agreed following one or two reminders (second stage); and the remainder of participants consented following three or more reminders (final stage). Cumulative distributions of sociodemographic characteristics differed little between second and final stage participants. Odds ratios for maternal multivitamin use were similar between second and final stage participants, whereas those for maternal and paternal smoking tended to decline. Although follow-up measures were necessary to enroll most families, use of more than two reminders did not appear to increase the representativeness of the sample; however, termination of recruitment after only two reminders would have led to different conclusions. Future studies require data collection protocols that encourage participation from all population subgroups, and one alternative is presented.