1. 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

2. 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

3. 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

4. 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 € € €

5. Recruitment

6. Cost-benefit analysisHR CH NL
Number of ads 2 3 1
Total costs for all ads € € €
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

7. 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

8. Socio-economic status: employmentHR
(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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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)

16. Thank you for your attention!
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