A clinical trial to examine disparities in quitting between African-American and White adult smokers: Design, accrual, and baseline characteristics

Abstract

Background: African-Americans smoke fewer cigarettes per day than Whites but experience greater smoking attributable morbidity and mortality. African-American-White differences may also exist in cessation but rigorously designed studies have not been conducted to empirically answer this question.

Methods/design: Quit2Live is, to our knowledge, the first head-to-head trial designed with the primary aim of examining African-American-White disparities in quitting smoking. Secondary aims are to identify mechanisms that mediate and/or moderate the relationship between race and quitting. The study is ongoing. Study aims are accomplished through a 5-year prospective cohort intervention study designed to recruit equal numbers of African-Americans (n=224) and Whites (n=224) stratified on age (<40, ≥40) and gender, key factors known to impact cessation, and all within a restricted income range (≤400% federal poverty level). All participants will receive 12 weeks of varenicline in combination with smoking cessation counseling. The primary outcome is cotinine-verified 7-day point prevalence abstinence from smoking at week 26. Secondary outcomes are cotinine-verified 7-day point prevalence abstinence from smoking at weeks 4 and 12.

Discussion: Findings from Quit2Live will not only address if African-American-White disparities in quitting smoking exist but, more importantly, will examine mechanisms underlying the difference. Attention to proximal, modifiable mechanisms (e.g., adherence, response to treatment, depression, stress) maximizes Quit2Live's potential to inform practice. Findings will provide an empirically-derived approach that will guide researchers and clinicians in identifying specific factors to address to improve cessation outcomes and reduce tobacco-related morbidity and mortality in African-American and White smokers.

Trial registration number: ClinicalTrials.gov: NCT01836276.

Keywords: African-American; Disparities; Smoking cessation; Varenicline; White.

Figure 1

Time to Accrual by Strata* *Time to accrual was calculated as the time between when the study opened for enrollment through when the last participant was enrolled into each stratum. Recruitment for all groups began on February 4, 2013. AA=African American

Figure 2

Participant Flow During Screening and Enrollment by Strata Eligibility Rate = eligible/screened, Enrollment Rate = enrolled/eligible