Using Facebook to recruit to a national online survey investigating complementary medicine product use in pregnancy and lactation: A case study of method.

Background: Online recruitment can be targeted efficiently to recruit specific samples for survey research. It has been shown to be a cost-effective method of recruitment, and useful for geographically dispersed populations.

Objectives: To describe the use of Facebook to recruit a targeted sample of expectant and breastfeeding mothers to a national online survey. Different techniques to assess response rates using data provided by Facebook are also described.

Methods: Participants accessed an anonymous online survey through a link included in posts from a Facebook page specifically set up for the research. Recruitment strategies were primarily of two types. Firstly, Facebook was paid to promote posts by displaying them on potential participants' Facebook feeds. Secondly, by purposive and snowball recruitment through the sharing of posts on relevant Facebook pages. Post success was measured by the reach, impressions, link clicks, post clicks, and click through rates; and for boosted posts, the cost per day, and cost per engagement with the post as well. Traditional methods of calculating response rates, and response rates using post clicks and survey link clicks were calculated.

Results: After 10 weeks of recruitment, 1418 participants had enrolled in the study, and of these 810 (57.1%) completed the 20-minute (70 question) survey. Women participated from across Australia. Both paid and purposive approaches to promotion contributed to recruitment success. Paid promotions at higher costs for fewer days were the most successful. Total paid promotion costs were (Australian) $1147.97 (or $1.44 per completed survey). Purposive promotion was slower, but also contributed significantly to the number of people who saw the posts and clicked through to the survey. Traditional response rate calculations showed a response rate of 0.8%. Using post clicks and survey link clicks in calculations, resulted in response rates of 23.1% and 42.7%, respectively.

Conclusions: A combination of paid promotions and purposive and snowball recruitment on Facebook were used to successfully recruit 1418 participants resulting in 810 completed surveys over a 10-week period, at a low cost per participant. Use of additional methods to measure response rates may be useful in measuring the success of using Facebook posts in recruitment.