Facebook ads as recruitment for online drug surveys: the Holy Grail? Dijana Jerković University Psychiatric Hospital Vrapče Martina Lotar Rihtarić Faculty of Education and Rehabilitation Sciences, University of Zagreb Tvrtko Horvat European Monitoring Centre for Drugs and Drug Addiction Lisbon, 25 October 2017

Introduction Facebook is the most popular social media Currently 2.06 billion monthly active users (Statista, 2017) Increasingly used as a method to target and survey individuals about health risk behaviors (Thornton et al, 2016) European Web Survey on Drugs – FB ads: to compare methodology and characteristics of respondents in different countries

Participants 18-65+, consumed at least once in the last 12 months one or more of the drugs: cannabis, amphetamines, ecstasy, cocaine Ads were applied in Croatia, Switzerland, and the Netherlands Eligible participants: agree to participate and drug use in the last year

Recruitment Campaigns HR CH NL Ad language Croatian German, French Dutch No of ads 2 ads (different ad placement) 3 ads (different duration, language, ad placement) 1 ad Targeting Country; age; specific interests (music, events, etc: 28) Country; age FB page New page created Existing page used Duration (2016) 04-18/04 22/5-04/07 09-29/09 Budget € 1 232.00 € 1 677.09 € 100.00

Recruitment

Cost-benefit analysis HR CH NL Number of ads 2 3 1 Total costs for all ads € 1 232.00 € 1 677.09 € 100.00 Number of clicks 14 791 4 292 707 Cost per a click € 0.08 € 0.39 € 0.14 Number of eligible subjects 3 581 1 281 394 Cost per participant € 0.34 € 1.31 € 0.25

Age & gender HR (N=3581) CH (N=1281) NL (N=394) Average age 18-83 M=24.36; SD=6.50 18-73 M=25.16; SD=7.97 18-60 M=30.25; SD=8.35 Age by groups 18-24 62.7 62.6 30.2 25-34 24.8 25.1 39.6 35-44 5.9 8.2 23.4 45+ 1.8 3.3 5.8 Gender Male 62.2 67.7 54.3 Female 36.6 31.9 45.4 Trans 0.9 0.3

Socio-economic status: employment HR (N=3129) CH (N=1113) NL (N=326) Employment status (%) Full-time 33.1 41.2 53.4 Part-time 5.3 12.5 18.1 Self-employed 7.7 5.9 6.6 Student 42.6 32.4 16.3 Unemployed 8.9 4.2 2.5 Other 2.4 3.9 3.7

Place of living & household composition HR (N=3132) CH (N=1115) NL (N=326) Place of living City 49.4 37.0 17.8 Town 37.7 30.0 53.7 Village 12.9 32.9 28.5 Household composition HR (N=2287) CH (N=771) NL (N=298) One person living alone 31.6 48.0 32.2 A couple without children 18.6 27.4 20.8 A couple with child(ren) 38.9 37.6 One adult with child(ren) 10.9 6.1 9.4

Cannabis use Have never used: RH 6.3%; CH 3.8%, NL 11.6% HR (N=2826) Frequency of cann use in last 12 months (%) Infrequent (<11 days) 16.0 22.2 35.5 Occasional (11-50) 16.8 14.9 20.4 Regular (51-250) 30.2 22.6 19.4 Intensive (>250) 36.9 40.3 24.7 I HR i CH se značajno razlikuju od NL. Između HR i CH nema razlike. HR (N=795) CH (N=417) NL (N=66) No. of days used cann in last 12 months M=238.62 SD=136.01 M=235.77 SD=142.31 M=166.71 SD=152.96 F=8.207; p<.05

MDMA use Have never used: RH 51.2%; CH 42.1%, NL 3.9% HR (N=1161) NL (N=292) Frequency of MDMA use in last 12 months (%) Daily 0.5 - 0.3 Almost daily 1.0 0.2 Not daily but more than once a week 3.2 2.6 3.1 Once a week 7.7 5.9 4.5 < than once a week - least once a month 22.6 19.6 36.3 < than once a month 65.1 71.6 55.5 Značajna razlika samo između HR i CH. HR i NL vjerojatno nije značajno zbog manjeg broja ispitanika u NL HR (N=1129) CH (N=414) NL (N=287) No. of days used MDMA in past 12 months M=20.63 SD=48.50 M=14.24 SD=31.80 M=14.23 SD=30.13 F=4.843; p<.05

Amphetamines use Have never used: RH 59.6%; CH 56.3%, NL 26.8% HR Frequency of amph use in past 12 months (%) Daily 1.1 1.4 Almost daily 3.0 3.4 Not daily but more than once a week 6.8 6.7 8.0 Once a week 10.3 11.8 7.4 < than once a week - least once a month 23.4 21.2 24.6 < than once a month 55.5 55.9 55.4 HR (N=808) CH (N=280) NL (N=163) No. of days used amph in last 12 months M=34.85 SD=63.91 M=34.40 SD=68.28 M=32.82 SD=64.12 F=0.067; p>05

Cocaine use Have never used: RH 62.7%; CH 52.8%, NL 29.8% HR (N=716) Frequency of coca use in past 12 months (%) Daily 2.1 1.5 0.6 Almost daily 1.8 4.1 1.1 Not daily but more than once a week 7.5 6.2 Once a week 3.8 6.7 7.9 < than once a week - least one a month 15.8 23.2 33.2 < than once a month 72.5 57.1 51.1 Značajna razlika samo između HR i CH HR (N=692) CH (N=332) NL (N=175) No. of days used coca in last 12 months M=20.07 SD=52.36 M=29.51 SD=62.80 M=26.13 SD=52.97 F=3.461; p<.05

Discussion Ad price - the lowest in HR (a „bid” system?) RH & CH – younger age groups; more males (FB: female network vs drugs: male phenomenon?) NL: FB more popular among older age groups? More intensive cannabis users participated from HR & CH than NL MDMA – more frequent users in HR than CH (Caution - NL: smaller number of participants) Amphetamines – no differences Cocaine – more frequent users in CH than HR

Conclusion High number of respondents Mostly young age groups Recreational use: added value (not present in the GPS) Time & budgetary affordable Might be a valuable strategy - for „hard to reach” respondents - in surveys with „difficult” topics Limitations connected with online surveys (e.g. non- representative samples)

Thank you for your attention! Questions? Comments? dijana.jerkovich@gmail.com