Major recruitment events May 2010 to March 2012. C, community events; E, emails or mailed letters to individuals or smaller groups; I, internet ad or website posting; ME, mass email to listserv or purchased email list; MM, mass mailing; N, newspaper ad; R, radio ad; TV, television ad. (* denotes multiple runs during period). Not shown: flyers posted or “word of mouth”. Events shown in blue were in Providence and those in black were done in North Carolina. Symbols indicate when a cohort was randomized at each location: # in North Carolina; @ in Providence.