Gripenberg-Abdon et al 2012

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

RESEARCH

Open Access

Measuring substance use in the club setting:
a feasibility study using biochemical markers
Johanna Gripenberg-Abdon1,2*, Tobias H Elgán2, Eva Wallin1, Marjan Shaafati3, Olof Beck3 and Sven Andréasson1

Abstract
Background: During the last few decades the use of club drugs (e.g., cocaine, amphetamines) has been of
increased concern in nightlife settings. Traditionally, surveys have been used to estimate the use of club drugs,
however, they mostly rely on self-reports which may not be accurate. Recent advances have allowed for readily
accessible drug testing methods such as oral fluid drug testing. Nevertheless, research using oral fluid sampling to
measure the frequency of drug use in the club environment is scarce. The objective of this study is to evaluate the
feasibility of measuring the frequency of alcohol and drug use among Swedish clubbers using breath alcohol and
oral fluid drug testing.
Method: The setting was a 40 hour electronic music dance event (EMDE) on a cruise ship on the Baltic Sea,
departing from Sweden, with 875 passengers. Groups of participants at the EMDE were randomly invited to
participate. Data were collected with face-to-face and self-administered questionnaires. Further, oral fluid samples
were collected to determine illicit drug use, and blood alcohol concentration (BAC) levels were measured using a
breath analyzer.
Results: A total of 422 passengers were asked to participate in the study whereof 21 declined (5.0% refusal rate).
Of the 401 study participants (accounting for 45.8% of all attendees), 5 declined oral fluid drug testing. Results
show that there was a discrepancy between self-reported and actual drug use as 10.1% of the participants were
positive on illicit drug use (amphetamines, ecstasy/MDMA, cannabis, cocaine), while only 3.7% of the participants
reported drug use during the last 48 hours. The average BAC level was 0.10% and 23.7% had BAC levels ≥ 0.15%,
while 5.9% had levels below the detection limit. The mean BAC levels for the illicit drug users were significantly
higher (p = 0.004) than for non-drug users (0.13% vs. 0.10%). Self-reported AUDIT-C scores (using a threshold of ≥ 5
for men and ≥ 4 for women) revealed that 76.0% of the men and 80.7% of the women had risky alcohol
consumption patterns.
Conclusion: This study indicates that it is feasible to conduct breath alcohol and oral fluid drug testing in a
Swedish club setting.
Keywords: Blood alcohol concentration, BAC, Club drugs, ?“?Clubs against Drugs?”?, Cruise ship, Electronic music
dance event, EMDE, Illicit drug, Oral fluid drug testing, Saliva

Background
The use of illicit drugs in the nightlife setting is a public
health concern since it is associated with violence, drug
driving, and risky sexual behavior [1-5]. In Sweden, problems related to club drug use have been attributed to
an increased availability of club drugs and a reduction
* Correspondence: [email protected]
1
Department of Public Health Sciences, Karolinska Institutet, Stockholm,
Sweden
Full list of author information is available at the end of the article

in drug prices [6,7], as well as an increase in the number
of licensed premises with extended opening hours [8,9].
In 2002, STAD (Stockholm Prevents Alcohol and Drug
Problems) initiated a multi-component communitybased club drug prevention program, named “Clubs
against Drugs”. Program evaluations showed an increase
in doormen interventions towards drug-intoxicated
patrons (e.g., refused entry into the club) [10,11], a
decrease in self-reported drug use among staff at
licensed premises, and a decrease in staff’s observed

© 2012 Gripenberg-Abdon et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

drug use among patrons [12]. Nevertheless, club drugs
at licensed premises remain a major problem in the
Swedish nightlife scene, and we are missing information
on actual frequency rates of illicit drug use among
patrons.
There are established protocols for measuring patrons’
blood alcohol concentration (BAC) in the nightlife setting (e.g., [13-15]). In contrast, similar protocols for
measuring illicit drugs have been lacking due to the
challenges of collecting biological specimens like blood
and urine that have traditionally been used for detection
of drugs and their metabolites. However, recent
advances in the drug testing field have allowed for the
use of alternative specimens such as oral fluid, which
now can be used to detect a variety of drugs including
amphetamines, cocaine, ecstasy/MDMA, opioids, and
cannabis [16-18]. Oral fluid is readily accessible and
sampling can be carried out by non-medical personnel
without need for special facilities.
Based on these advances, researchers in the U.S. developed a portal methodology to collect both self-reported
data and biochemical assays to measure alcohol and illicit drug use among patrons as they entered and exited
clubs [19]. Using this methodology, Miller and co-workers reported that one out of four patrons at so called
electronic music dance events (EMDEs) was using drugs
[20], and the most frequently used illicit drugs were
cannabis, cocaine, amphetamine, and ecstasy/MDMA
[21]. They further found that about 33% of the patrons
had blood alcohol concentrations (BAC) levels of 0.08%
or more.
Since the portal methodology has proven to be a useful tool to investigate alcohol and drug use among
patrons at EMDEs in the U.S., it was our intent to
adopt this method and test it at a similar event in Sweden. However, unlike the U.S. nightlife scene, similar
events rarely occur in Sweden today, mainly due to the
increased control and sanctions taken by the police
authorities as a reaction towards the appearance of the
rave culture [22] in Sweden during the 90s. Although
EMDEs are rare in Sweden, these events are nowadays
arranged on cruise lines that depart from Sweden and
take place on international waters where Swedish laws
and regulations do not apply and Swedish Authorities
have difficulties operating.
Furthermore, while data collected in the U.S. demonstrate the willingness among club-goers to participate in
studies involving biological drug testing [21], we had
concerns regarding the adoption of a similar methodology in a Swedish setting-especially given the strict enforcement of Swedish narcotic laws. Additionally, the
overall population in Sweden is perceived to have more
restrictive attitudes towards illicit drug use as compared
to the U.S.. For instance, although staff at licensed

Page 2 of 10

premises in Stockholm report high levels of drug use,
almost 70% agree with Swedish drug laws stating that it
should be illegal to be drug-intoxicated [12].
The objective of this study is to evaluate the feasibility
of measuring the frequency of alcohol and drug use
among Swedish clubbers, using breath alcohol and oral
fluid drug testing, in a similar setting as in the aforementioned U.S. studies (i.e., EMDEs). In particular, we
are interested in the overall participation rate and the
acceptance to give an oral fluid sample. We will also
present data on self-reported and measured alcohol and
illicit drug use, participants’ risky alcohol consumption
patterns, and the discrepancy between self-reported and
measured drug use. To our knowledge, this is the first
study outside of the U.S. using biochemical sampling in
a club setting to measure the frequency of patrons’ illicit
drug use.

Methods
Setting

Since large EMDEs in Sweden today are routinely
hosted on cruise ships, cruise lines and organizers of
EMDEs were approached to gain approval to conduct
the study on an EMDE cruise. Permission was obtained
to carry out the study at a specific event, however, it
was requested that neither the name of the cruise line,
the organizer, the EMDE, or the exact date of the event
be publicized.
Data collection took place on a 40 hour EMDE cruise
departing from Sweden during the spring of 2011.
There were a total of 875 paying passengers and
approximately 100 additional people involved in the
production of the EMDE such as DJs and sound/lightning technicians. The minimum age requirement to participate in the EMDE cruise was 18 years (which is the
legal drinking age in Sweden). When boarding the ship,
all passengers were required to pass by police officers
and drug detecting dogs. In addition, there were a number of police officers present in the departure hall.
All passengers received an event program by the organizers which also contained information about the purpose of the study, that participation was strictly
voluntary and confidential (i.e., no personal identifying
information was collected), and that participants would
receive an incentive in the form of a food coupon worth
approximately U.S. $15 or 10€.
On the ship there were several restaurants and bars,
and a total of two dance floors. Alcohol could be purchased both at bars/restaurants and at a duty free liquor
store selling beer, wine, and hard liquor which could be
consumed in the passengers’ cabins. During the 40 hour
event there were approximately ten security staff that
circulated around the ship including the dance floors,
bars, and the cabin hallways. The main task of the

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

security staff was to maintain order and prevent unruly
and aggressive behavior. In principle, the entire cruise
ship was turned into a club, from 10 p.m. and 6 a.m. for
two nights, during which time the EMDE attendees
moved between different areas on the ship (i.e., the
“club area” was not only restricted to the dance floors
and bars, and alcohol could be consumed everywhere
and at any time).
Measures

To collect data on demographics and patterns of alcohol
and drug use the participants were interviewed using a
face-to-face questionnaire and asked to complete an
additional self-administered questionnaire. The face-toface questionnaire contained questions on demographics
(e.g., age, gender), alcohol consumption during the present day/night, and the AUDIT-C (Alcohol Use Disorders Identification Test Consumption) instrument
[23,24] screening for risky alcohol use. The self-administered questionnaire contained other demographic questions (e.g., marital status, residence, employment) and
questions concerning licit and illicit drug use. Substances surveyed included cannabis, cocaine, amphetamines, and ecstasy/MDMA with regards to use ranging
from ever use to last 48 hour use, as well as planning to
use at this event.
Participant BAC levels were measured using breath
analyzers (Lion Alcolmeter™ SD-400, Lion Laboratories
Limited, Barry, U.K.) shown to have a high validity [25].
Recent drug use was measured by collecting oral fluid
samples (Quantisal™ Saliva Collection Device, Immunalysis Corporation, Pomona, CA, U.S.A.) which have
effectively been used to test for illicit drugs [17]. A
number of studies have confirmed the validity and reliability of utilizing oral fluids to detect recent use of illicit
drugs by comparing urine and/or blood tests with oral
fluids [26-29]. Based on previous research, the analysis
of the oral fluid samples were limited to the four most
commonly used club drugs in Sweden: cannabis,
cocaine, amphetamine, and ecstasy/MDMA [12].
Procedure

On board the cruise ship, a data collection area was
allotted by the organizer. This area was centrally located
in a passageway nearby the information desk, the duty
free liquor store, as well as the two dance floors. A modified portal survey methodology was used, where data
were collected once for each participant, instead of twice
(upon entering and exiting an event) as described by
Miller and co-workers [19,21]. In order to collect entering and exiting data as in the U.S. study, data collection
would have to occur when passengers boarded and disembarked the ship. However, boarding and leaving the

Page 3 of 10

ship takes place within a limited time-frame (approximately 1.5 hours for boarding and 30 minutes for disembarking), which would have resulted in very few study
participants. Further, measuring BAC levels when passengers disembarked, several hours after the EMDE
ended, would not have reflected the actual intoxication
levels during the event. As a result, we collected data during the EMDE as the attendees moved between the different dance floors, bars, cabins, and the liquor store.
A total of two research supervisors and 12 research
staff, divided into four teams (each consisting of three
staff members) worked in parallel during the two nights
of data collection. Groups, as opposed to individual persons, were randomly invited to participate by a recruiter
in each team. The reason to recruit groups was based
on previous research indicating that the refusal rate is
lower when an entire group is allowed to participate
[19]. The recruiter approached the first person passing
down the passageway and gave information about the
study. If the person belonged to a group, all members of
that group were invited to participate.
An informed consent statement was verbally presented
to all the participants and a copy of this information
was offered. The process of obtaining consent was documented by the research team. Since it was important to
maintain confidentiality, no signatures were required. If
a whole group, or a person(s) in a group, refused to participate, the recruiter recorded them as drop-outs and
noted the gender, approximate age, and asked them why
they did not want to participate.
Once the individuals had agreed to participate, they
were given a glass of water to rinse their mouths to get
accurate readings from alcohol breath test and oral fluid
samples. The face-to-face interview was then initiated,
followed by the breath test. The result from the breath
analyzer was instantly available on site. If requested, the
participants were given their BAC level. Next, oral fluid
samples were collected from the participants by placing
the Quantisal™ collection pad in the mouth. During
this process, the participants filled out the self-administered questionnaire. When data collection was completed the participants were given the food coupon. To
assure that each participant was only included in the
study once during the 40 hour event, the participants
were marked with an ultraviolet (UV)-inked stamp. A
unique identification number for each participant
allowed the pairing of the two questionnaires and oral
fluid sample. The oral fluid samples were stored at
approximately 2°C throughout the remainder of the
cruise. Once the EMDE was completed the oral fluid
samples were transported directly to the Pharmacological Laboratory at the Karolinska University Hospital,
where they were stored at -20°C pending analysis.

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

Oral fluid analysis

The Quantisal™ collection devices with collection pads
were thawed and subjected to mild shaking for 1 h at
room temperature. Each container was weighed, followed by centrifugation and careful removal of the collection pad. Sample preparation was performed as
described by Øiestad et al. [18] with only minor
changes: 90 ng/mL delta-9-tetrahydrocannabinol-d3 and
50 ng/mL amphetamine-d5 were added to a saline buffered solution (Extraction Buffer, Immunalysis, Pomona,
CA, U.S.A.) to be used as internal standards for delta-9tetrahydrocannabinol (THC) and alkaline drugs (amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), cocaine) respectively. After being
dried using a stream of nitrogen, samples containing
alkaline drugs were redissolved in 55 μL 0.1% formic
acid, and THC samples in 15 μL methanol. Thereafter,
40 μL methanol: 0.1% formic acid (50:50) was added to
each sample and transferred into screw cap vials. The
samples were analyzed using positive electrospray liquid
chromatography-tandem mass spectrometry (LC-MS/
MS, Waters Quattro Premier), operating in the selected
reaction monitoring mode. The applied reporting limit
was 1 ng/mL (neat oral fluid) for all analytes.
Statistical analysis

The SPSS Statistics 19 software (IBM Corporation) was
used to analyze the data in terms of descriptive analyses,
generating frequency and contingency tables. Here,
bivariate analyses yielding Pearson c 2 statistics were
used to investigate the relationship between variables
using a significance level of p ≤ 0.05. In addition, a ttest was used to compare means between independent
samples, and Cohen’s  was used as a measure of agreement between self-reported drug use and oral fluid drug
testing. Finally, to further investigate the association
between variables and control for potential confounders,
multivariate logistic regression analyses was performed
yielding odds ratios (O.R.) and corresponding 95% confidence intervals (C.I.). Here, the dependent variables
were “illicit drug use” (yes vs. no) and “BAC levels” (≥
0.1% vs. < 0.1%), while the independent variables were
“gender”, “age” (≥ 25 years vs. < 25 years), “relationship
status” (no relationship vs. relationship), “time” (2 a.m.
or later vs. before 2 a.m.), frequency of “clubbing” (≥ 1
times/week vs. < 1-2 times/month), overall “risky alcohol consumption” pattern (yes vs. no), as indicated by
AUDIT-C using threshold scores of ≥ 5 for men and ≥
4 for women.

Page 4 of 10

Results
The purpose of this study was to evaluate the feasibility of
using breath alcohol and oral fluid drug testing to measure
the frequency of alcohol and drug use among Swedish
clubbers. Overall, data collection proceeded according to
plans. The two research supervisors and the four research
teams worked from 10 p.m. (4 hours after departure) in
the evening until 6 a.m. in the morning. Throughout the
EMDE, the teams were fully occupied collecting data from
the participants; as soon as one group of participants had
completed data collection, a new group of participants
were recruited. A total of 422 passengers (belonging to
238 groups having a mean group size (± S.D.) of 1.73 ±
0.97) were asked to participate in the study whereof 21
(5.0%, belonging to 12 groups, mean size 2.70 ± 1.16)
declined, resulting in 401 participants (36.2% females).
Thus, 45.8% of the 875 paying passengers were included
in the study. During the first night of the EMDE, data
were collected from 206 attendees (51.4% of the whole
study sample), and on the second night an additional 195
attendees (48.6%) were included in the study. About half
of the participants (44.9%) took part in the study before 2
a.m. and the other half after 2 a.m.. On average, each of
the four research teams collected data from about six participants per hour. Missing data on specific items varied
but never exceeded 7.2% (which concerned a question
whether or not the participants were planning to use illicit
drugs at this event). A total of five participants declined to
give saliva samples. It is worth mentioning, that in some
cases (< 5 participants) the saliva collection procedure was
overly time consuming (> 15 min) due to dryness of
mouth, and a number of participants reported that their
low saliva production was related to medications (e.g.,
anti-depressants).
Demographics

The overall characteristics of the participating patrons
are presented in Table 1. The mean age of the participants was 25.7 ± 6.0 years (26.5 ± 6.2 and 24.2 ± 5.2 for
men and women, respectively) ranging from 18 to 45
years. The proportion of students was approximately
30%. Of these, about 25% were high school students and
about 60% were studying at university level. The participants were from various regions in Sweden: 40.1% from
one of the three largest cities (Stockholm, Gothenburg,
and Malmoe), 55.1% from minor cities or rural areas,
and 4.7% from abroad. Almost half of the participants
(48.5%) reported going out clubbing 1-2 times per
month, while 32.0% reported clubbing ≥ 1 times per
week, and 19.2% reported clubbing rarely.

Ethics statement

This study has been approved by the Regional Ethical
Review Board at the Karolinska Institutet in Stockholm
(Registration number: 2009/797-31/4).

Illicit drug use

Self-reported ever use of drugs among the participants
was 49.1% and 9.2% reported that they usually use drugs

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

Page 5 of 10

Table 1 Overall demographics and characteristics of patrons
Characteristic

Females (n = 145) % (n)

Males (n = 256) % (n)

Total (n = 401) % (n)

62.8 (91)

48.8 (125)

54.0 (216)

25-29

22.1 (32)

21.5 (55)

21.7 (87)

30-39

13.8 (20)

25.8 (66)

21.4 (86)

1.4 (2)

3.9 (10)

3.0 (12)

Employed, full time

28.2 (40)

65.5 (163)

51.9 (203)

Employed, part time

31.0 (44)

12.0 (30)

18.9 (74)

Unemployed

14.1 (20)

4.8 (12)

8.2 (32)

Student, full time

31.7 (45)

19.9 (50)

24.2 (95)

Age
< 25 years

40+
Employment/student status

Student, part time

7.0 (10)

6.0 (15)

6.4 (25)

Nonstudent

59.9 (85)

70.9 (178)

66.9 (263)

In a relationship

53.8 (78)

42.5 (108)

46.7 (186)

Not in a relationship

44.8 (65)

55.9 (142)

51.9 (207)

Relationship status

when clubbing. Further, 3.7% reported having used
drugs during the last 48 hours, and 6.0% were planning
to use drugs during the EMDE (Table 2 and Figure 1).
The most commonly self-reported drug during the last
48 hours was cannabis, followed by amphetamine,
cocaine, and ecstasy/MDMA. A total of 396 saliva samples were collected and analyzed. Analysis revealed that
10.1% of the participants tested positive for at least one
illicit drug (20.0% of the drug users were polydrug
users). The most commonly used drugs were amphetamines, followed by ecstasy/MDMA, cannabis, and
cocaine. The mean values (ng/mL) and ranges were:
amphetamine, 1587 (2-32352); methamphetamine, 725
(15-1880); MDMA, 930 (43-7288); cocaine, 11224; THC,
255 (58-297). Of the 40 illicit drug users the majority
were males (75.0%). The frequency of any illicit drug
use was 11.8% for men and 6.9% for women (Table 3),
however, this difference is non-significant. Both men
and women had the same drug preference but none of
the women tested positive for cocaine or metamphetamine. Of those who tested positive for drug use over the
course of the two evenings, a slightly higher number
(57.5%) were found during the second night of data collection. There were a larger (although non-significant)
proportion of participants (62.5%) who were positive on

drugs later in the night (2 a.m. or later) compared to
earlier (before 2 a.m.).
There is a poor agreement (Cohen’s  = 0.198, p =
0.001) between self-reported and actual drug use since
only 16.7% of those who tested positive for any drug
(using oral fluid drug testing) reported having used
drugs during the last 48 hours. Furthermore, of those
who tested negative for any drugs, 2.3% reported that
they had used drugs during the last 48 hours.
Alcohol use

The mean number of self-reported standard drinks
(defined as drinks containing 12 grams of pure alcohol,
e.g., one bottle of beer, one glass of wine) consumed by
the participating patrons each evening/night was 8.8 (±
5.7) drinks (9.9 ± 6.2 and 6.8 ± 4.0 for men and women,
respectively). The average BAC level was 0.10% (± 0.06,
range 0.00-0.28); for men the mean value was 0.11% (±
0.06) and for women 0.08% (± 0.06). As seen in Figure
2A, about 62% of the participating patrons (70% for
men, 49% for women) had a BAC level of ≥ 0.08%,
while approximately 23% (28% for men, 14% for
women) had a measured level of ≥ 0.15%, and almost
6% (7% for men, 3% for women) had a level of ≥ 0.20%.
About 6% (4% for men, 9% for women) of the

Table 2 Patrons self-reported drug use (%)
Have
tried

A couple of times/
month

Every
weekend

A couple of times/
week

Last 48
hrs

Usually use when
clubbing

Planning to use at this
event

Cannabis

41.5

7.2

2.6

1.5

2.1

6.1

1.9

Amphetamines

18.5

2.3

0.3

0.0

1.3

3.7

1.9

Cocaine

12.3

0.8

0.0

0.3

0.8

1.6

0.8

Ecstasy/MDMA

16.2

0.3

0.0

0.0

0.5

1.8

0.8

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

Page 6 of 10

Figure 1 Frequency of illicit drug use. A comparison between the frequency (in per cent) of illicit drug use as determined by oral fluid drug
testing (dark grey, n = 396) compared to self-reported drug use within the past 48 hours (light grey, n = 382). Since questions about
metamphetamine use were not included in the self-report questionnaire, a subsequent estimate was not available (asterisk).

participants had not consumed any detectable levels of
alcohol. There was no difference concerning measured
BAC levels between the first and second night of data
collection, nor before or after 2 a.m.. However, there are
significant differences between males and females as
54.4%, and 37.3% of men and women, respectively, had
a BAC level of 0.10% or more (c2 = 10.58, d.f. = 1, p =
0.001). Other factors that were significantly associated
to participants having a BAC level of 0.10% or more was
illicit drug use, an overall risky alcohol consumption
pattern, and frequency of clubbing (Table 4). These
associations remained after controlling for possible confounding factors using multivariate analyses.
Using an AUDIT-C threshold commonly used in European countries (i.e., ≥ 4 for women and ≥ 5 for men)
reveals that 76.0% of the men and 80.7% of the women
(77.7% for both genders) had self-reported risky alcohol
consumption patterns (Figure 2B). This proportion
increases to 87.8% and 92.4% for men and women
(89.5% for both genders), respectively, using a threshold
commonly used in the U.S. (i.e., ≥ 3 for women and ≥ 4
for men). These gender differences with regards to risky
alcohol consumption are not significant.
Alcohol and illicit drug use

A greater proportion (although not significant) of the
illicit drug users had self-reported risky alcohol consumption according to the AUDIT-C scores compared
to non-drug users (87.5% vs. 76.6%). All the illicit drug
users had been drinking alcohol. The mean BAC levels

for the illicit drug users were significantly higher than
for non-drug users, 0.13% compared to 0.10% (t = 2.893,
df = 390, p = 0.004). The significant association between
BAC levels and illicit drug use remained after controlling for possible confounding factors as seen in Table 4
(p = 0.02).

Discussion
These findings indicate that it is feasible to measure the
frequency of alcohol and drug use among Swedish clubbers using breath alcohol and oral fluid drug testing.
Previous studies using breath analyzers to measure BAC
levels among patrons have successfully been conducted
in a Swedish nightlife setting [30,31], but oral fluid drug
testing has never been used to measure illicit drug use.
During the planning phase of this study, concerns were
raised regarding the possibility of using biochemical
markers to measure illicit drug use among Swedish
clubbers. This was mainly due to potential cultural differences between countries concerning illicit drug use.
For instance, showing obvious signs of illegal drugintoxication is perceived to be more stigmatized in Sweden as compared to the U.S.. This would impede studying illicit drug use among Swedish clubbers as they
might be less inclined to take part in this type of study.
Nevertheless, the data collection procedure went according to plans and we were surprised by the amount of
positive feedback from the EMDE attendees as well as
the management and staff at the cruise ship. In fact, we
were invited by the cruise line management to contact

Table 3 Frequency of actual illicit drug use for males and females (%)
Amphet amine

Metamph etamine

Cannabis

Cocaine

Ecstasy/MDMA

Any illicit drug

Male

8.6

1.2

2.0

0.4

2.4

11.8

Female

4.2

0

0.7

0

2.8

6.9

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

Figure 2 Measured blood alcohol concentrations and AUDIT-C
scores. (A) Blood alcohol concentrations (BAC) for males (n = 250,
grey filled circles), females (n = 142, black filled circles), and both
genders (n = 392, solid line) distributed over the percentile range.
(B) Total AUDIT-C scores (ranging from 0-12 points) for males (n =
254, grey filled circles), females (n = 145, black filled circles), and
both genders (n = 399, solid line) distributed over the percentile
range.

them if we wanted to conduct further studies. The
research teams’ recruiters were able to approach nearly
half of the EMDE attendees and 95.0% agreed to participate which is a considerable higher participation rate
than the 56.0% reported in the U.S. study [21].
There are several possible factors that may have influenced the high participation rate: (i) the recruitment
process was crucial to the study and appropriate staff
(same age group as the EMDE attendees, outgoing personality, and socially skilled) were carefully selected and
trained, (ii) the incentive (food coupon corresponding to
U.S. $15 or 10€) appeared to be valuable for this target
group, (iii) the oral fluid sample device was easy to
administer, well accepted by the participants, and did
not give results on site, (iv) the EMDE organizers gave
written support to our study in the event program, and
finally, (v) the participants showed great interest in finding out their BAC levels. In fact, not only were we interested in measuring the participant’s actual BAC levels,

Page 7 of 10

our thought was that the inclusion of an initial BAC test
in the data collection process would make the oral fluid
testing for illicit drug use less dramatic.
Almost all participants, 94.1% had been drinking alcohol and 10.1% tested positive for illicit drug use. From
an international perspective the frequency for illicit drug
use might seem low. In comparison, at the U.S. EMDEs
an average of 26.0% of the attendees were drug-positive
when leaving the events [21]. There are several potential
explanations for the observed lower levels of illicit drugs
among the Swedish clubbers. It is possible that the
lower levels might reflect the actual drug use among the
patrons at this event. EMDE patrons in Sweden might
use illicit drugs to a lesser extent than for example their
counterparts in the U.S.. However, as in many other
countries EMDEs in Sweden have been associated with
high frequency of illicit club drug use. More specifically,
EMDEs on cruise ships in Sweden have previously had
problems with illicit club drugs. During an EMDE cruise
in 2005, the police authority (working undercover on
the cruise) estimated that about half of the patrons were
under the influence of illicit drugs and over 30 patrons
were arrested (when leaving the cruise ship) for drug
crimes, and cocaine, amphetamines, and ecstasy/MDMA
were confiscated. As a result, preventive measures have
been taken by the cruise lines, police authorities, and
the customs control department, which could have
resulted in decreased amounts of drugs brought on to
the cruise ship. For example, the fact that all passengers
had to pass by the police’s drug detecting dogs when
boarding, along with the police authority present in the
departure hall could explain the comparatively lower
observed illicit drug rates. In fact, at this cruise the
police authority reported about 20 drug-related crimes
at the point of boarding the ship. It could also be the
case that the patrons that used drugs during the cruise
were underrepresented in our sample. Even though
45.8% of the patrons were included in the study and the
refusal rate was low, the patrons that used drugs could
have avoided walking by the data collection area.
There is a discrepancy between self-reported drug use
and the results from the oral fluid tests as only 3.7% of
the participants reported having used drugs during the
last 48 hours, while 10.1% tested positive for drug use
(Figure 1). Even though self-reported illicit drug use was
confidential, only 16.7% of the drug users reported having used any drug during the last 48 hours. This type of
underreporting of self-reported drug use has also been
observed previously, and could possibly be explained by
reporting bias as people may be reluctant to report illicit
drug use. It could also be the case that some participants were unaware of drug intake. Nevertheless, the
agreement between self-reported and actual drug use
was poorer in our study (Cohen’s  = 0.198, p = 0.001)

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

Page 8 of 10

Table 4 Results from bivariate and multivariate analyses using logistic regression modeling to adjust for possible
confounders
Predictor variables

Bivariate analyses

Multivariate analyses

c2 (d.f.)

O.R.

95% C.I.

c2 (d.f.)a

O.R.

95% C.I.

7.66(1)**

2.65

1.30-5.40

5.63(1)*

2.53

1.18-5.43
0.71-6.61

D.V.: Illicit drug use (yes vs. no)b
BAC level (≥ 0.1% vs. < 0.1%)
Risky alcohol consumption (yes vs. no)

2.47(1)

2.14

0.81-5.63

1.84(1)

2.17

Gender (males vs. females)

2.40(1)

1.79

0.85-3.78

1.35(1)

1.59

0.72-3.45

Clubbing (≥ 1 times/week vs. < 1-2 times/month)

1.22(1)

1.46

0.75-2.85

0.21(1)

1.18

0.57-2.46

Time (2 a.m. or later vs. before 2 a.m.)

2.76(1)

1.79

0.89-3.58

2.88(1)

1.89

0.91-3.94

Age (≥ 25 years vs. < 25 years)

0.02(1)

0.95

0.49-1.83

0.34(1)

0.81

0.40-1.36

Relationship status (no relationship vs. relationship)

0.71(1)

0.75

0.39-1.46

2.32(1)

0.58

0.28-1.17

D.V.: BAC level (≥ 0.1% vs. < 0.1%)
Illicit drug use (yes vs. no)

7.66(1)**

2.65

1.30-5.40

5.79(1)*

2.55

1.19-5.45

Risky alcohol consumption (yes vs. no)

13.51(1)***

2.57

1.54-4.30

8.50(1)**

2.28

1.31-3.96

Gender (males vs. females)

10.58(1)**

2.00

1.31-3.05

7.49(1)**

1.88

1.19-2.94

Clubbing (≥ 1 times/week vs. < 1-2 times/month)

11.83(1)**

2.11

1.38-3.25

4.05(1)*

1.62

1.01-2.60

Time (2 a.m. or later vs. before 2 a.m.)

0.96(1)

1.22

0.82-1.82

0.28(1)

1.12

0.73-1.72

Age (≥ 25 years vs. < 25 years)

0.54(1)

1.05

0.71-1.56

0.89(1)

1.24

0.80-1.92

Relationship status (no relationship vs. relationship)

3.06(1)

1.43

0.96-2.14

0.67(1)

1.20

0.77-1.87

Wald c2 statistics based on logistic regression modeling
b
DV is the dependent variable
*p < 0.05
**p < 0.01
***p < 0.001
a

compared to what has been reported by Johnson and
co-workers (Cohen’s  = 0.53, p < 0.01) [32]. Furthermore, 2.3% of those with negative drug tests had
reported using illicit drugs during the last 48 hours.
This could be explained by a person believing they have
ingested a specific drug while they have ingested
another substance. Drugs can be detected in oral fluids
for up to three days and depends on a variety of factors
such as the physiochemical properties of specific drugs,
the strength (i.e., drugs may be diluted) and the amount
of a drug taken, and the route of administration. In
addition, the metabolism of drugs varies from person to
person and depends on factors like age, body mass, liver
function, and genetic factors [29,33]. The frequency of
positive drug tests/self-reported drug use was low for
some drugs, precluding comparative analysis between
the drugs. However, one could speculate that the greater
discrepancy between self-reported drug use and oral
fluid drug test found for amphetamine and ecstasy/
MDMA is due to a less acceptance of these drugs as
compared to cannabis and cocaine (considered by some
people to be a softer drug, and a more glamorous drug,
respectively).
The BAC levels found in this study (mean value 0.1%)
were high compared to other studies conducted at university student pubs in Sweden (mean values between

0.075-0.087%) [30]. At the U.S. EMDEs, 33% of the
patrons had BAC levels ≥ 0.08%, while in our sample
this figure corresponded to 62% [21]. One reason for
the observed high BAC levels is probably the high availability and low control of the large quantities of alcohol
that could be purchased in the duty free shop and consumed in the cabins at any time during the EMDE. In
contrast, regular clubs in Sweden are covered by Swedish alcohol laws, stating that obviously intoxicated
patrons should not be served alcohol or even be denied
entry into licensed premises. Another reason could be
related to the event taking place on a cruise ship where
EMDE attendees only needed to find their way back to
their cabins (i.e., attendees did not have to be concerned
about home transportation).
The participants’ high BAC levels measured in this
study were significantly associated with frequent clubbing
and an overall (i.e. not related to this event) risky alcohol
consumption pattern as indicated by the AUDIT-C
scores (77.7% and 89.5% had risky alcohol consumption
using European and U.S. threshold scores, respectively)
(Table 4). In other words, it may be the case that problem
drinkers are attracted to this type of event. However, the
vast majority (80.4%) of our sample reported going clubbing at least 1-2 times per month which means that these
participants attend land-based clubs on a regular basis.

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

Furthermore, all the illicit drug users had been drinking
alcohol and even had significantly higher BAC levels relative the non-illicit drug users. The association between
illicit drug use and a high BAC level remained even after
controlling for other possible confounders using multivariate analyses (Table 4). Therefore, the common perception that clubbers who use illicit drugs drink less
alcohol than non-illicit drug users was not supported by
the results from this study.
There are a few limitations to this study worth mentioning. We were allotted a data collection area on the cruise
ship, that the EMDE attendees did not have to pass by,
and it could be the case that drug-intoxicated attendees
avoided our research team. One might also question the
accuracy in self-reports by highly intoxicated people. In
this study, 23% had BAC levels ≥ 0.15% which might have
affected cognitive functioning, memory, as well as judgment; all contributing to lower capability of filling out a
questionnaire. This study was conducted during a particular EMDE at a cruise ship, which can be regarded as a special type of club environment. Moreover, when boarding
the ship, there were drug detecting dogs and police officers
present which may have affected the frequency of drug
use. For instance, if this study had been conducted at
clubs taking place at licensed premises located in a city, it
is possible that our results would have been different (e.g.,
higher refusal rates and different frequency rates). An
important challenge when conducting a portal survey at
regular clubs concerns the recruiting process as people do
not want to waste any time participating in research, since
they are eager to get into the event or quickly leave. At
regular clubs people can arrive and leave whenever they
want, whereas passengers on a cruise ship have nowhere
else to go. In order to gain a better understanding of drug
use at EMDEs we would have to include a broader range
of venues as well as a greater number of events. Further,
less commonly used drugs such as GHB (gamma-hydroxybutyric acid), mushrooms, and benzodiazepines could be
added to the analysis of the oral fluid samples.
Traditionally, the majority of alcohol and drug prevalence studies rely on surveys, however, our study highlights the importance of using biochemical markers to
properly estimate drug use in this type of setting. The
methodology used in this study provides the opportunity
to combine and measure the actual BAC levels and illicit drug use. Not only can this method be used to follow
drug trends in settings such as the club scene, sport
events, and festivals, it can also be used to increase the
awareness of the club drug problem in communities,
mobilize stakeholders, and evaluate the effects of various
drug prevention programs. Furthermore, studies have
shown that young adults are a high risk-group for drug
and alcohol-related problems and this study suggest that
one arena where this age group can be reached with

Page 9 of 10

preventive measures is at EMDEs. It is important to find
settings where emerging adults can be targeted with
alcohol and drug prevention programs such as Responsible Beverage Service programs [34-36], and club drug
environmental strategies [10,12].

Conclusions
The purpose of this study was to test the feasibility of
measuring the frequency of alcohol and drug use in a
Swedish club setting using breath and oral fluid analysis.
The vast majority (95.0%) of the approached EMDE
attendees agreed to participate in the study, whereof
only five attendees declined the oral fluid drug testing.
We found that about one out of ten participants were
positive on illicit drug use and the average BAC level
was 0.10%. The illicit drug users had significantly higher
mean BAC levels than the non-drug users. We conclude
that it was feasible to use alcohol breath and oral fluid
drug testing at this EMDE. However, to what extent this
method can be used in other types of settings needs to
be explored in future studies. Nevertheless, we believe
that this methodology, combining surveys with biochemical markers, provides a useful and more accurate
tool to measure actual drug and alcohol use in the
nightlife scene as well as other types of settings.
Acknowledgements
This research was funded by grants from the Swedish Council for Working
Life and Social Research, and the Swedish National Institute of Public Health.
The funders had no role in study design, data collection and analysis,
decision to publish, or preparation of the manuscript. We would also like to
thank Dr. Allen Thomas for helpful comments.
Author details
1
Department of Public Health Sciences, Karolinska Institutet, Stockholm,
Sweden. 2STAD, Stockholm Centre for Psychiatric Research and Education,
Department of Clinical Neuroscience, Karolinska Institutet and Stockholm
County Council Health Care Provision, Stockholm, Sweden. 3Department of
Medicine, Section of Clinical Pharmacology, Karolinska Insitutet, Stockholm,
Sweden.
Authors’ contributions
EW, JGA, SA, and THE planned and designed the experiments. JGA and THE
were responsible for and performed the data collection. MS contributed to
data collection. JGA and THE analyzed the data and interpreted the results.
EW and SA contributed to the interpretation of results. MS and OB analyzed
the oral fluid samples. JGA and THE wrote the paper. All authors
commented on and approved the final manuscript.
Competing interests
The authors declare that they have no competing interests.
Received: 29 November 2011 Accepted: 9 February 2012
Published: 9 February 2012
References
1. Bellis MA, Hughes K, Bennett A, Thomson R: The role of an international
nightlife resort in the proliferation of recreational drugs. Addiction 2003,
98:1713-1721.
2. Bellis MA, Hughes K, Lowey H: Healthy nightclubs and recreational
substance use-From a harm minimisation to a healthy settings
approach. Addict Behav 2002, 27:1025-1035.

Gripenberg-Abdon et al. Substance Abuse Treatment, Prevention, and Policy 2012, 7:7
http://www.substanceabusepolicy.com/content/7/1/7

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.
15.

16.
17.
18.

19.

20.
21.

22.
23.

24.

25.

Chinet L, Stephan P, Zobel F, Halfon O: Party drug use in techno nights: a
field survey among French-speaking Swiss attendees. Pharmacol Biochem
Behav 2007, 86:284-289.
Degenhardt L, Dillon P, Duff C, Ross J: Driving, drug use behaviour and
risk perceptions of nightclub attendees in Victoria, Australia. Int J Drug
Policy 2006, 17:41-46.
Furr-Holden D, Voas RB, Kelley-Baker T, Miller B: Drug and alcohol-impaired
driving among electronic music dance event attendees. Drug Alcohol
Depend 2006, 85:83-86.
Fender E, Irlander Å, Gripe I, Guttormsson U, Hibell B:
Narkotikaprisutvecklingen i Sverige 1988-2007 [The development of drug prices
in Sweden 1988-2007] Stockholm Sweden: Council for Information on
Alcohol and Other Drugs (CAN); 2008.
Guttormsson U, Andersson B, Hibell B: Ungdomars drogvanor 1994-2003Intervjuer med 16-24-åringar [Drughabits of adolescents 1994-2003-interviews
with 16-24 year olds] Stockholm Sweden: Council for Information on Alcohol
and Other Drugs (CAN); 2004.
Chikritzhs T, Stockwell T: The impact of later trading hours for Australian
public houses (hotels) on levels of violence. J Stud Alcohol 2002,
63:591-599.
Chikritzhs T, Stockwell T: The impact of later trading hours for hotels
(public houses) on breath alcohol levels of apprehended impaired
drivers. Addiction 2007, 102:1609-1617.
Gripenberg Abdon J, Wallin E, Andréasson S: Long-term effects of a
community-based intervention: 5 year follow-up of “Clubs against
Drugs”. Addiction 2011, 106:1997-2004.
Gripenberg J, Wallin E, Andréasson S: Effects of a community-based drug
use prevention program targeting licensed premises. Subst Use Misuse
2007, 42:1883-1898.
Gripenberg Abdon J, Wallin E, Andréasson S: The “Clubs against Drugs”
program in Stockholm, Sweden: two cross-sectional surveys examining
drug use among staff at licensed premises. Subst Abuse Treat Prev Policy
2011, 6:2.
Bellis MA, Hughes K, Quigg Z, Morleo M, Jarman I, Lisboa P: Cross-sectional
measures and modelled estimates of blood alcohol levels in UK nightlife
and their relationships with drinking behaviours and observed signs of
inebriation. Subst Abuse Treat Prev Policy 2010, 5:5.
Perham N, Moore SC, Shepherd J, Cusens B: Identifying drunkenness in
the night-time economy. Addiction 2007, 102:377-380.
Thombs DL, O’Mara R, Dodd VJ, Hou W, Merves ML, Weiler RM, Pokorny SB,
Goldberger BA, Reingle J, Werch CC: A field study of bar-sponsored drink
specials and their associations with patron intoxication. J Stud Alcohol
Drugs 2009, 70:206-214.
Bosker WM, Huestis MA: Oral fluid testing for drugs of abuse. Clin Chem
2009, 55:1910-1931.
Drummer OH: Drug testing in oral fluid. Clin Biochem Rev 2006,
27:147-159.
Øiestad EL, Johansen U, Christophersen AS: Drug screening of preserved
oral fluid by liquid chromatography-tandem mass spectrometry. Clin
Chem 2007, 53:300-309.
Voas RB, Furr-Holden D, Lauer E, Bright K, Johnson MB, Miller B: Portal
surveys of time-out drinking locations: a tool for studying binge
drinking and AOD use. Eval Rev 2006, 30:44-65.
Miller BA, Holder HD, Voas RB: Environmental strategies for prevention of
drug use and risks in clubs. J Subst Use 2009, 14:19-38.
Miller BA, Furr-Holden D, Johnson MB, Holder H, Voas R, Keagy C: Biological
markers of drug use in the club setting. J Stud Alcohol Drugs 2009,
70:261-268.
Weir E: Raves: a review of the culture, the drugs and the prevention of
harm. CMAJ 2000, 162:1843-1848.
Bush K, Kivlahan DR, McDonell MB, Fihn SD, Bradley KA: The AUDIT alcohol
consumption questions (AUDIT-C): an effective brief screening test for
problem drinking. Ambulatory Care Quality Improvement Project
(ACQUIP). Alcohol Use Disorders Identification Test. Arch Intern Med 1998,
158:1789-1795.
Gual A, Segura L, Contel M, Heather N, Colom J: Audit-3 and audit-4:
effectiveness of two short forms of the alcohol use disorders
identification test. Alcohol Alcohol 2002, 37:591-596.
Andersson L: Provning Mätkvalitet Sållningsinstrument Lion SD-400 [Test of
Measure Accuracy of the Instrument Lion SD-400] Linköping: SKL, National
Laboratory of Forensic Science; 1994.

Page 10 of 10

26. Laloup M, Tilman G, Maes V, De Boeck G, Wallemacq P, Ramaekers J,
Samyn N: Validation of an ELISA-based screening assay for the detection
of amphetamine, MDMA and MDA in blood and oral fluid. Forensic Sci Int
2005, 153:29-37.
27. Niedbala RS, Kardos KW, Fritch DF, Kardos S, Fries T, Waga J, Robb J,
Cone EJ: Detection of marijuana use by oral fluid and urine analysis
following single-dose administration of smoked and oral marijuana.
J Anal Toxicol 2001, 25:289-303.
28. Schepers RJ, Oyler JM, Joseph RE Jr, Cone EJ, Moolchan ET, Huestis MA:
Methamphetamine and amphetamine pharmacokinetics in oral fluid
and plasma after controlled oral methamphetamine administration to
human volunteers. Clin Chem 2003, 49:121-132.
29. Verstraete AG: Detection times of drugs of abuse in blood, urine, and
oral fluid. Ther Drug Monit 2004, 26:200-205.
30. Johnsson KO, Berglund M: Education of key personnel in student pubs
leads to a decrease in alcohol consumption among the patrons: a
randomized controlled trial. Addiction 2003, 98:627-633.
31. Johnsson KO, Berglund M: Do responsible beverage service programs
reduce breath alcohol concentration among patrons: a five-month
follow-up of a randomized controlled trial. Subst Use Misuse 2009,
44:1592-1601.
32. Johnson MB, Voas RA, Miller BA, Holder HD: Predicting drug use at
electronic music dance events: self-reports and biological measurement.
Eval Rev 2009, 33:211-225.
33. Lillsunde P: Analytical techniques for drug detection in oral fluid. Ther
Drug Monit 2008, 30:181-187.
34. Gliksman L, McKenzie D, Single E, Douglas R, Brunet S, Moffatt K: The role
of alcohol providers in prevention: an evaluation of a server
intervention programme. Addiction 1993, 88:1195-1203.
35. Holder HD, Wagenaar AC: Mandated server training and reduced alcoholinvolved traffic crashes: a time series analysis of the Oregon experience.
Accid Anal Prev 1994, 26:89-97.
36. Wallin E, Gripenberg J, Andréasson S: Too drunk for a beer? A study of
overserving in Stockholm. Addiction 2002, 97:901-907.
doi:10.1186/1747-597X-7-7
Cite this article as: Gripenberg-Abdon et al.: Measuring substance use in
the club setting: a feasibility study using biochemical markers.
Substance Abuse Treatment, Prevention, and Policy 2012 7:7.

Submit your next manuscript to BioMed Central
and take full advantage of:
• Convenient online submission
• Thorough peer review
• No space constraints or color figure charges
• Immediate publication on acceptance
• Inclusion in PubMed, CAS, Scopus and Google Scholar
• Research which is freely available for redistribution
Submit your manuscript at
www.biomedcentral.com/submit