“…Overall, the 19 RCTs included were conducted in the United States [13, 56, 59, 60, 62-68, 71, 72], Brazil [61,70], India [58,73], Iran [69], and China [57]. Study participants were recruited from hospitals [57, 63-67, 69, 73], outpatient clinics [61,62] and schools [58]. The process of recruitment also included using purchased lists and health-plan enrollment files [56,59] and multiple other mechanisms, including flyers, newspaper advertisements, web-based announcements, brochures, public health departments, tumor registry systems, and doctor referrals [13,60,68,71,72].…”