Overcoming challenges of recruiting cancer patients into clinical trials: insights from a randomized trial of app-based smoking cessation interventions.

Behavioral clinical trials among cancer patients often fail to meet recruitment goals - especially for underrepresented groups. Comparing recruitment strategies on participant accrual and cost can inform the use of cost-effective recruitment strategies for enrollment of diverse populations of cancer patients. In this study, we compared social media, internet sites, and clinic-based recruitment on accrual, cost, and characteristics of cancer patients (i.e., sociodemographic, cancer type/stage, and smoking habits) enrolled in a randomized trial of app-based smoking cessation interventions. Fisher's exact tests for categorical variables and analysis of variance for continuous variables were used to compared data between recruitment strategies. In 35 months, 427 cancer patients from 45 US states enrolled in the trial out of 3,936 screened (rate of participation, 10.8%). Social media recruited over eight times the number of enrolled participants (n=340, 79.6%) compared with Internet sites (n=43, 10.1%) and clinics (n=42, 9.8%). Most (80.1%) participants were women, with mean age 52.3 years. About 20.4% of participants were from underrepresented racial/ethnic backgrounds, 23.0% were rural residents, and 23.7% were uninsured. Over 32 cancer types and all cancer stages were represented. Breast cancer was the most common diagnosis (n=129/427, 30.2%), followed by lung cancer (n=96/427, 23.8%). Internet recruitment generated a higher proportion of men (30.2% vs. 26.2% clinics vs. 17.4% social media,