Recruiting Diverse Smokers: Enrollment Yields and Cost

To help tobacco control research better include vulnerable populations, we sought to identify effective ways to recruit diverse smokers. In 2014–2015, we recruited 2149 adult cigarette smokers in California and North Carolina, United States, to participate in a randomized trial of pictorial cigarette pack warnings. The most effective means of recruiting smokers were the classified advertising website Craigslist (28% of participants), word of mouth (23%), Facebook (16%), and flyers or postcards (14%). Low-income and African American smokers were more likely to respond to interpersonal contact (including staff in-person recruitment and word of mouth) than were high-income and non-African American smokers (all p < 0.05). Hispanic and gay, lesbian, and bisexual smokers were more likely to be recruited by Craigslist than non-Hispanic and straight smokers (both p < 0.05). Of the recruitment methods requiring cost, the cheapest was Craigslist ($3–7 per smoker). The most expensive methods were newspaper ads in California ($375 per smoker) and staff in-person recruiting in North Carolina ($180 per smoker). Successfully recruiting diverse smokers requires using multiple methods including interpersonal, online, and other media. Craigslist and word of mouth are especially useful and low-cost ways to recruit diverse smokers.