24071796

PMC4471475

Purpose

As epidemiological studies expand to examine gene–environment interaction effects, it is important to identify factors associated with participation in genetic studies. The National Birth Defects Prevention Study is a multisite case–control study designed to investigate environmental and genetic risk factors for major birth defects. The National Birth Defects Prevention Study includes maternal telephone interviews and mailed buccal cell self-collection kits. Because subjects can participate in the interview, independent of buccal cell collection, detailed analysis of factors associated with participation in buccal cell collection was possible.

Methods

Multivariable logistic regression models were used to identify the factors associated with participation in the genetic component of the study.

Results

Buccal cell participation rates varied by race/ethnicity (non-Hispanic whites, 66.9%; Hispanics, 60.4%; and non-Hispanic blacks, 47.3%) and study site (50.2–74.2%). Additional monetary incentive following return of buccal cell kit and shorter interval between infant’s estimated date of delivery and interview were associated with increased participation across all racial/ethnic groups. Higher education and delivering an infant with a birth defect were associated with increased participation among non-Hispanic whites and Hispanics.

Conclusion

Factors associated with participation varied by race/ethnicity. Improved understanding of factors associated with participation may facilitate strategies to increase participation, thereby improving generalizability of study findings.

CDC Public Access

IYP0/Intramural CDC HHS/United States
P30 ES005605/ES/NIEHS NIH HHS/United States