Table 5.

Costs per enrolled participant by media type.^a

Study authors (year)	Cost per enrolled participant
	Social media	Traditional methods	Other online media
Abbate et al (2017) [20]	N/Ab	US $8.28c	N/A
Adam et al (2016) [21]	Can $20.28	Can $24.15	N/A
Bracken et al (2019) [23]	N/A	Aus $594	N/A
Frandsen et al (2014) [27]	Aus $56.34	Aus $52.33	N/A
Frandsen et al (2016) [9]	Aus $42.34	Aus $21.52	N/A
Guthrie et al (2019) [28]	US $593	US $356	N/A
Heffner et al (2013) [29]	US $172.76	US $5.27-$46.98	US $26.19-$50.26
Huesch et al (2018) [30]	US $18	US $635	N/A
Ince et al (2014) [31]	€5.33	N/A	N/A
Jones et al (2017) [33]	US $66.46	US $149.62	N/A
Juraschek et al (2018) [34]	US $1426	US $436-$917	N/A
Kayrouz et al (2016) [10]	US $37	US $40	N/A
Kendall et al (2018) [35]	N/A	Aus $2141c	N/A
Nash et al (2017) [38]	Aus $45.15-$176	N/A	N/A
Partridge et al (2015) [39]	Aus $945.33	Aus $144.52-$212.51	Aus $11.98-$571.45
Raviotta et al (2016) [41]	US $110	US $61	N/A
Volkova et al (2017) [46]	NZ $5d	NZ $4-$179	NZ $4
Waltman et al (2019) [47]	US $119.38	US $29.36-$926.90	US $1000
Watson et al (2018) [48]	US $40.51	US $20.30	US $13.95-34.71

^aCurrency exchange rates of Can $1=US $0.75, Aus $1=US $0.72, €1=US $1.17, and NZ $1=US $0.66 were applicable at the time of publication.

^bN/A: not applicable.

^cCost per enrolled participant across all media.

^dIncludes cost using Craigslist.