Table 4.

Enrollment rates by recruitment method.^a

Study authors (year)	Enrolled from social media, %	Enrolled from traditional methods, %	Enrolled from other online media, %
Abbate et al (2017) [20]	16	40	57
Adam et al (2016) [21]	36	64	N/Ab
Alley et alc (2016) [22]	53d	47e	N/A
Bracken et al (2019) [23]	2	94	1
Buckingham et al (2017) [24]	50	26	24
Burrell et al (2012) [25]	23	77e	N/A
Frandsen et al (2014) [27]	52	47	N/A
Frandsen et al (2016) [9]	53	47	N/A
Guthrie et al (2019) [28]	8	92	N/A
Heffner et al (2013) [29]	5	25	70
Huesch et al (2018) [30]	65	35	N/A
Ince et al (2014) [31]	78	2	0
Jones et al (2012) [32]	7	94	N/A
Jones et al (2017) [33]	62	38	N/A
Juraschek et al (2018) [34]	3	77	N/A
Kayrouz et al (2016) [10]	86	14	N/A
Kendall et al (2018) [35]	33	67	N/A
Kira et al (2016) [36]	4	88	N/A
Kuhn et al (2017) [37]	18	22	60
Partridge et al (2015) [39]	2	71	25
Rabin et al (2013) [40]	0	100	N/A
Raviotta et al (2016) [41]	20	80	N/A
Rounds et al (2019) [42]	3	81	16
Sanchez et al (2018a) [43]	0	19	5
Sanchez et al (2018b) [43]	0	53	4
Volkova et al (2017) [46]	43	46	11
Waltman et al (2019) [47]	16	44	1
Watson et al (2018) [48]	49	11	39

^aSome studies allowed participants to be counted in multiple recruitment and enrollment methods.

^bN/A: not applicable.

^cItalics signify studies that reported the highest enrollment rates from social media.

^dIncludes participants enrolled from targeted Facebook ads only.

^eIncludes participants enrolled from both traditional and other online media.