Abstract
Background/Aims The aim of this study is to identify predictors of participation in women of different racial groups to optimize future recruitment efforts.
Methods We randomly selected and assessed predictors of participation on Kaiser Permanente Southern California adult female members (n = 107,378) between November 2012 and June 2013. Women were asked to provide a saliva sample for a research biobank. Potential predictors of participation were age, long-term membership (= 5 years), no significant gaps in health care coverage (<3 month in last 3 years), physical examination within the last 3 years and neighborhood education and income.
Results The overall participation among women was 6.8%. Restricting recruitment to women with = 5 years of membership, no major gaps in health care coverage, and at least one physical examination within the last 3 years improved participation in Whites (from 7.1% to 14.3) and Hispanics (from 2.5% to 5.0%) but only modestly in Blacks (from 2.0% to 3.6%). In logistic regression models predicting participation, the strongest predictors in Whites and Hispanics were having a physical examination (OR 1.25, 95%-CI 1.17–1.33 in Whites and 1.45, 1.28–1.65 in Hispanics) and long-term membership (OR 1.19, 95%-CI 1.12–1.27 in Whites and 1.32, 1.16–1.50 in Hispanics). None of the restrictions significantly predicted participation in Blacks (p for interaction with race <0.001).
Conclusions Applying restrictions based on regular physical examinations and longer membership may potentially increase participation of non-Hispanic White and Hispanic women in a research biorepository.
