Background: Little is known about what factors influence women to participate its trials designed for women at high risk for breast cancer. Yet the recruitment phase is of utmost importance in determining whether the trial can achieve its goals. The purpose of this study was to examine predictors of participation in a risk counseling trial for first-degree relatives of breast cancer patients.
Methods: Subjects were identified by their relatives who had received a diagnosis of breast cancer at one of six institutions. Letters of introduction were sent to potentially eligible, unaffected relatives. They were informed about the risk counseling study and given the opportunity to decline. Letters were sent to 1392 first-degree relatives; of these, 1149 women were contacted for an interview and 14% refused. Of the 987 respondents, 47% accepted and 53% declined to participate. Bivariate and multivariate statistics were used to examine predictors of participation.
Results: In the total sample, there were five significant multivariable predictors of participation: level of education, recent clinical breast examination (CBE), objective and perceived breast cancer risk, and any current use of alcohol. Participation was moderated by time since the relative's diagnosis. There was a statistically significant relationship to education such that women with a higher level of education were significantly more likely to participate if they were approached within 2 months of their relative's diagnosis of breast cancer.
Conclusions: Like many other kinds of trials, participants in this risk counseling trial were significantly more likely to have more than a high school education and more likely to be nonsmokers than the nonparticipants. They also were significantly more likely to drink alcohol (dichotomous measure), have had a recent CBE, and have higher subjective and objective breast cancer risks. Different types of recruitment strategies may be needed depending on the characteristics of the people being recruited and the timing of the invitation.