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Recruitment is often a difficult and costly part of any human research study. Social media and other emerging means of mass communication hold promise as means to complement traditional strategies used for recruiting participants because they can reach a large number of people in a short amount of time. With the ability to target a specified audience, paid Facebook advertisements have potential to reach future research participants of a specific demographic. This paper describes the experiences of a randomized controlled trial in Edmonton, Alberta, attempting to recruit healthy pregnant women between 8 and 20 weeks’ gestation for participation in a prenatal study. Various traditional recruitment approaches, in addition to paid Facebook advertisements were trialed.
To evaluate the effectiveness of paid advertisements on Facebook as a platform for recruiting pregnant women to a randomized controlled trial in comparison with traditional recruitment approaches.
Recruitment using traditional approaches occurred for 7 months, whereas Facebook advertisements ran for a total of 26 days. Interested women were prompted to contact the study staff for a screening call to determine study eligibility. Costs associated with each recruitment approach were recorded and used to calculate the cost to recruit eligible participants. Performance of Facebook advertisements was monitored using Facebook Ads Manager.
Of the 115 women included, 39.1% (n=45) of the women who contacted study staff heard about the study through Facebook, whereas 60.9% (n=70) of them heard about it through traditional recruitment approaches. During the 215 days (~7 months) that the traditional approaches were used, the average rate of interest was 0.3 (0.2) women/day, whereas the 26 days of Facebook advertisements resulted in an average rate of interest of 2.8 (1.7) women/day. Facebook advertisements cost Can $506.91 with a cost per eligible participant of Cad $20.28. In comparison, the traditional approaches cost Cad $1087, with approximately Cad $24.15 per eligible participant. Demographic characteristics of women were similar between the 2 recruitment methods except that women recruited using Facebook were significantly earlier in their pregnancy than those recruited using traditional approaches (
Paid Facebook advertisements hold promise as a platform for reaching pregnant women. The relative ease of placing an advertisement, the comparable cost per participant recruited, and the dramatically improved recruitment rates in comparison with traditional approaches highlight the importance of combining novel and traditional recruitment approaches to recruit women for pregnancy-related studies.
ClinicalTrials.gov NCT02711644; https://clinicaltrials.gov/ct2/show/NCT02711644 (Archived by WebCite at http://www.webcitation.org/6kKpagpMk)
The recruitment portion of human research studies is often expensive and resource intensive. Finding interested and eligible participants can be challenging and can take longer than expected. Extending the recruitment period can negatively affect time-sensitive study funding, delay data collection and analyses, and ultimately delay the release of evidence necessary to change practice. For prenatal studies, an additional challenge is to find women at an appropriate gestational age.
Traditional recruitment approaches for prenatal studies include printed posters and brochures, radio, television, and newspaper advertisements, word of mouth, and approaching pregnant women in clinics [
Edmonton, Alberta, has been noted previously to be a difficult center in which to access and recruit pregnant women for research [
The overall objective of the RCT was to examine the efficacy of supportive prenatal counseling versus standard prenatal care in promoting appropriate weight gain and dietary intake among pregnant women. The recruitment goal was 70 healthy pregnant women between 8 and 20 weeks’ gestation, living in the greater Edmonton area. The purpose of this paper was to evaluate the effectiveness of paid advertisements on Facebook as a platform for recruiting pregnant women to this RCT in comparison with traditional recruitment approaches.
Recruitment for the RCT using traditional approaches, including printed posters and brochures, word of mouth, newspaper advertisements, local television news health report, booths at mommy and baby fairs, and advertisements in physicians’ offices, started in July 2015. A Facebook account was created to distribute paid advertisements that ran intermittently from October 6 to December 1, 2015, for 26 nonconsecutive days. Advertisements were targeted to Facebook users based on the following criteria: female, 23-40 years of age, living in the Edmonton + 25-mile radius geographic area, and “Interests” related to pregnancy. The “Interests” used were Childbirth, Infant, Maternity clothing, Mommy connections, Parent, Prenatal, Prenatal care, Prenatal development, Motherhood, Today’s Parent, Ultrasound, Prenatal nutrition, Family, and Parenting (
Performance of Facebook advertisements was monitored regularly and optimized in real time using Facebook Ads Manager. Following the trial of multiple paid Facebook advertisement campaigns, the advertisement performance was assessed by examining number of clicks and the amount of engagement. Engagement can be defined as interactions with the study advertisement such as likes, comments, or shares. Funds were reallocated to the Facebook advertisements with the highest number of clicks and highest rate of engagement. Advertisement performance was most affected by the location of the advertisement and the “Interests” specified. Advertisements located on the mobile newsfeed performed better than those on desktop newsfeed; therefore, desktop advertisements were turned off after 9 days. The “Interests”
Costs associated with each recruitment approach were recorded and used to calculate the cost to the study to recruit eligible participants. The time required by staff to support each of these approaches was not captured and therefore not included in the cost calculations. The local television news report (ie, news reporter, film crew, television airing of segment) was donated in kind, and therefore the costs associated with it were also not included in determination of costs.
Advertising performance statistics were collected from information provided by Facebook Ads Manager. Demographic information was self-reported by participants who were eligible and had consented to study participation. These data were collected through the Research Electronic Data Capture (REDCap) Consortium member site housed at the University of Alberta [
Ethics approval for the RCT was obtained from the Health Research Ethics Board–Health Panel at the University of Alberta (study ID number: Pro00054360). This study is registered at ClinicalTrials.gov (ID: NCT02711644).
A screenshot that shows the set-up of a paid Facebook advertisement.
A screenshot that shows the paid Facebook advertisements on a mobile phone.
A total of 11 women (11/126, 8.7%) did not indicate how they heard about the RCT and were excluded from further analyses. Of the 115 women included in analysis, 39.1% (n=45) of the women who contacted study staff heard about the study through Facebook, whereas 60.9% (n=70) of them heard about it through traditional approaches (
During the 215 days (~7 months) that the traditional approaches were used, the average rate of interest was 0.3 (0.2) women/day. The local television news report resulted in 18 women contacting the study and was the most successful component of the traditional approach. When the local television news report is excluded, the remaining traditional approaches had an average interest rate of 0.2 (0.1) women/day. In comparison, the 26 days of Facebook advertisements resulted in an average interest rate of 2.8 (1.7) women/day. The traditional approaches alone (ie, before launching Facebook advertisements) had an overall interest rate of 8.7 women/month. Adding Facebook advertisements to traditional recruitment approaches increased the overall interest rate to 29.7 women/month. Of note, the Facebook advertisements ran for 26 nonconsecutive days to avoid advertisement fatigue. The maximum number of consecutive days the advertisement was displayed was 8. Advertisements were stopped on day 8 as the performance statistics dropped on days 6-8.
The 45 women who contacted study staff in response to the Facebook advertisement resulted in 40 women who were screened and 25 who were eligible and agreed to participate in the study (55.6% of interested). This resulted in a recruitment rate of 0.96 eligible participants/day. Of the 70 women who expressed interest through traditional approaches, 64 were screened and 45 were eligible and agreed to participate (64.2% of interested), resulting in a recruitment rate of 0.21 eligible participants/day. The calculated (hypothetical) amount of time needed to recruit 70 women using only traditional approaches is 334 days and could be shortened to 73 days using Facebook advertisements.
Facebook advertisements cost Cad $506.91, with a cost of Cad $0.28 per click. Other forms of engagement with the Facebook advertisements included 55 likes, 24 comments, and 28 shares. Most of the comments consisted of the names of Facebook friends who would be notified of the tag. A few comments required response from the study team as they asked questions regarding the eligibility criteria. Facebook advertisements had a cost per eligible participant of Cad $20.28. In comparison, the traditional approaches cost Cad $1087 for all methods combined (ie, printing, media advertisements, mileage to deliver brochures to different venues, participation at mommy and baby fairs). Traditional approaches cost approximately Cad $24.15 per eligible participant.
Women recruited to the randomized controlled trial using traditional approaches and paid Facebook advertisements (n=115). The traditional approaches include methods listed in addition to other methods that consist of online classified advertisements, doctor referrals, blog posts, email newsletters, newspaper advertisements, mommy fairs, and online mom connection groups.
Proportion of interested women for the randomized control trial using Traditional approaches and paid Facebook Advertisements (n=115). The Traditional Approaches include methods listed in addition to ‘Other’ methods that consist of: Online classified advertisements, Doctor referrals, blog posts, email newsletters, newspaper advertisements, mommy markets and online mom connection groups.
Characteristics of women recruited using Facebook advertisements versus traditional approaches.
Characteristic | Recruitment method | ||
Facebook advertisements |
Traditional approaches |
||
Age, years, mean (SD) | 35 (4.6) | 34 (4.5) | .42 |
Gestational age, weeks, mean (SD) | 12.6 (3.7) | 14.7 (3.8) | .03 |
Prepregnancy BMIa, kg/m2, mean (SD) | 26.4 (5.9) | 24.8 (4.9) | .25 |
Born in Canada | 22 (88) | 36 (80) | .40 |
Not born in Canada | 3 (12) | 9 (20) | |
Single | 1 (4) | 2 (4) | .92 |
Married or common-law | 24 (96) | 43 (96) | |
Less than bachelor’s degree | 6 (24) | 17 (38) | .24 |
Bachelor’s degree or higher | 19 (76) | 28 (62) | |
< $70,000 | 2 (8) | 8 (18) | .26 |
> $70,000 | 23 (92) | 37 (82) | |
Part time | 6 (24) | 11 (24) | .97 |
Full time | 19 (76) | 34 (76) | |
One | 7 (28) | 18 (40) | .17 |
Two or more | 3 (12) | 2 (4) |
aBMI: body mass index.
This study highlights the improved time efficiency achieved by coupling Facebook advertisements with traditional approaches for recruitment of pregnant women to a research study. After a 3-month period of traditional recruitment, we decided to test Facebook recruiting. Along with traditional recruiting, we used Facebook for 26 nonconsecutive days. Had we relied solely on traditional methods of finding interested women, it would have taken close to 1 year to reach our recruitment target, and this was shortened to less than 6 months by adding Facebook advertisements as a recruitment method. This improvement in recruitment rates of pregnant women is similar to that reported by a study recruiting women before conception. Shere et al found that social media–based recruitment resulted in a 12-fold higher rate of recruits per month [
On the surface, the absolute costs of the 2 recruitment methods used in this study were comparable (Cad $24.15/eligible participant for traditional approaches and $20.28/eligible participant for Facebook advertisements). Neither of these costs included those incurred by study staff. Staff or trainee time, mileage, and other related costs can be difficult to measure. The time required to generate and post Facebook advertisements is typically less than that needed to pick up and distribute posters and brochures to multiple sites throughout a large city. One of our traditional approaches, the television health report, was donated “in kind” and involved a local news anchor along with a 1-person film crew. This would have been very costly had the study not been seen as a valuable news item. The free television health report is considered a traditional approach to recruitment. However, if its contribution to the traditional recruitment rate is removed, the cost per eligible participant for traditional approaches increases to Cad $33.97. Future studies should track resource investments, such as staff time, more thoroughly to better understand the relative savings or costs of social media compared with traditional recruitment approaches.
To our knowledge, no additional studies have been published within the last 2 years examining paid Facebook advertisements as a recruitment tool for prenatal studies. Changes in reach, access, and usage of Facebook over the 5 years that these studies and our study span make it difficult to fairly compare results between studies. Our Facebook click-through ratio was better than the 0.08% reported in the study by Arcia [
Our cost per advertisement click was slightly less than those reported by others. In several other studies, cost/click ranged from Cad $0.39/click [
This study suggests that Facebook is a promising platform for reaching and recruiting pregnant women to a research study. Facebook advertisements can be more targeted than many of the traditional approaches because it is possible to define specific demographic and geographic characteristics, and information can be directed to those who search terms on the Web that align with the “Interests” specified by the researcher. Specifying “Interests” related to pregnancy likely enhanced the effectiveness of our advertisements because pregnancy is often a life event that is shared on social media platforms, and Facebook can display the advertisement to users based on their recent activity on the Web. Our RCT is the first prenatal study to describe the “Interests” used in their advertisements. This could be advantageous by reducing the time needed to identify interested participants for a research study. Because most women use the Web to seek health-related information related to pregnancy, Facebook also holds potential as a useful way to distribute public health messages by using “Interests” to target this population [
Previous studies have noted a concern that recruitment through Web-based methods may result in a nonrepresentative population [
There are several limitations to this study. Our research team had little experience with Facebook advertisements before starting the study. The advertisements might have been more impactful or cost-effective if those formulating them had more experience developing, testing, and monitoring social media platforms and related statistics. Another limitation was that we could not determine whether women saw the advertisement on their personal Facebook page or if it came to them through a friend who saw it on Facebook. In our study, “word of mouth” was labelled as a traditional approach; however, the original study awareness may have originated from Facebook advertisements. This would underestimate the effectiveness of Facebook advertisements as a recruitment tool.
With ever-changing technology, researchers must stay current and utilize innovative approaches to find interested study participants. The ease of placing an advertisement on Facebook, the comparable cost per participant recruited, and the dramatically improved recruitment rates when Facebook advertisements were added to traditional approaches highlight the importance of combining novel and traditional recruitment techniques to efficiently recruit women to pregnancy-related research studies, even in geographic areas where recruitment is difficult [
randomized controlled trial
The authors thank all the women who participated and showed interest in the RCT. The authors also thank Ms Bethany Singleton, RD, for her help with data collection, Hara Nikolopoulos for her help with study logistic support, and Mr Dave Cornish who kindly offered his creativity and marketing expertise to trial Facebook recruitment advertisements. The RCT is funded by the Danone Institute of Canada as well as a Collaborative Research and Innovation Opportunities grant provided by Alberta Innovates: Health Solutions. LMA has received support through the Frederick Banting and Charles Best Canada Graduate Scholarship from the Canadian Institutes of Health Research. In addition, she has received scholarships from the University of Alberta including the Queen Elizabeth II Graduate Scholarship, the Anthony Fellowship in Human Nutrition, Hazel McIntyre Summer Research Award, and the Walter H Johns Graduate Fellowship.
None declared.