Using Behavioral Nudges to Engage Pregnant Women in a Smoking Cessation Trial: An Online Field Quasi-Experiment.

Evidence shows that behavioral nudges could be used to enhance enrollment rates in randomized controlled trials (RCTs) by addressing enrollment barriers, but research on this topic is limited. We conducted an online field quasi-experiment with separate pretest (October 2017-January 2018) and posttest (February-May 2018) samples designed to examine the use of behavioral nudges to engage pregnant smokers in a couple-focused smoking cessation RCT relying on online enrollment through paid Facebook ads and a dedicated website, by reporting aggregate Facebook ads and Google Analytics data. The Facebook ads pretest conversion rate of 1.6% doubled and reached 3.41% in the posttest period. The pretest eligibility assessment rate decreased from 10.3% to 6.46%, but registered a relative increase of approximately 50% in the posttest period, as opposed to the pretest. The number of women who signed the informed consent in the posttest period has increased with 63%, from a proportion of 8.54% in the pretest to 11.73% in the posttest period. These findings might lend support to integrating behavioral nudges in the recruitment and enrollment materials of RCTs to boost enrollment.