Recruiting pregnant smokers from Text4baby for a randomized controlled trial of Quit4baby

Recruiting pregnant smokers into clinical trials is challenging since this population tends to be disadvantaged, the behavior is stigmatized, and the intervention window is limited. The purpose of this study is to test the feasibility and effectiveness of recruiting pregnant smokers into a smoking cessation trial by sending recruitment text messages to an existing subscriber list. Recruitment messages were sent to subscribers flagged as pregnant in Text4baby, a national text messaging program for pregnant women and mothers. Four recruitment messages were rotated to test the effectiveness of different emotional frames and a financial incentive. Study staff called subscribers who expressed interest to screen for eligibility and enroll eligible women. Between October 6, 2015 and February 2, 2016, 10,194 recruitment messages were sent to Text4baby subscribers flagged as pregnant, and 10.18% (1038) responded indicating interest. No significant increase in cancellation was observed compared to subscribers who received other ad hoc messages. Of respondents, 54.05% (561) were reached by phone for follow-up, and 21.97% (228) were found to be eligible. Among the eligible, 87% (199) pregnant smokers enrolled. The recruitment message with a pride emotional appeal had a significantly higher response (p = 0.02) compared to the recruitment message with no emotional appeal, but enrollment did not significantly differ between recruitment messages with different emotional appeals. The recruitment messages with a reference to financial incentive yielded higher response (p < 0.01) and enrollment (p = 0.03) compared to a recruitment message without. This study demonstrates success recruiting pregnant smokers using text message. Future studies should consider building on this approach for recruiting high-risk populations.