Recruitment of asthmatic ethnic minorities into a methacholine research study: factors influencing participation.

Background: How to recruit minority participants into research studies has been an issue since 1993, when NIH funding guidelines required minorities to be included as research participants.

Objective: The purpose of this analysis was to determine what factors affected recruitment of asthmatic minorities into a large bronchoconstrictor study involving African-Americans, Hispanics/Mexican Americans, Asian/Pacific Islanders, and whites with mild asthma (forced expiratory volume in the first second of expiration > or = 70%).

Methods: Ethnic minorities were recruited for 3 years. Recruitment strategies included physician and clinic referrals, newspaper ads, posters in health care settings, asthma databases, and electronic resources.

Findings: After 3 years, the total number of referrals was 650, with 50 from medical doctor clinic settings and 600 from all of the other resources. The inclusion/exclusion criteria were clearly listed, but only 64.5% (419/650) of respondents met inclusion criteria. Of these, only 31.9% (134/419) [corrected] met pulmonary function testing criteria. Only 5, or 1% of the 50 medical doctor clinic referrals met inclusion criteria--1 participated. A total of 106, or 82.8%, completed all of the study procedures; for 87.7% of participants this was their first research experience. Hispanics/Mexican Americans accounted for only 14.8% of the total recruitment responses.

Conclusion: We believe our recruitment strategies did encourage ethnic minorities to participate, but the inclusion criteria of a positive methacholine response proved to be a study enrollment barrier.