African American smokers interested and eligible for a smoking cessation clinical trial: predictors of not returning for randomization.

Purpose: Recruitment is often the rate-limiting step in conducting clinical trials among ethnic minorities. Little is known about participants who consent and enroll into a trial, but do not return for randomization. Why participants fail to return for randomization is largely unknown.

Methods: We compared 287 enrolled African American smokers who did not return for randomization, to the 500 who returned and were randomized to participate in a clinical trial for smoking cessation in African Americans. Analyses were conducted to identify variables associated with not returning for randomization.

Results: Univariate comparisons found the nonrandomized group to be significantly different from those randomized. Logistic regression showed younger age, less readiness to quit, having been proactively recruited, lacking a regular source of health care, believing that they will be smoking in 6 months, less church attendance, and a lower literacy level to be jointly related with not returning for randomization.

Conclusions: African American participants who did not return for randomization into a clinical trial were different from those who did. Better understanding of these factors may allow researchers to target recruitment efforts resulting in enhanced accrual in clinical trials and increased efficiency.