This article was downloaded by: [Laurentian University] On: 05 October 2014, At: 04:39 Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Journal of Psychoactive Drugs Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ujpd20
Social Contacts and Ecstasy Offers: Findings of a Population-Based Study Andrew Smirnov B.A., G.Dip.Lib.Sci.
a b
, Jake M. Najman Ph.D.
d
d
M.P.H. Dip.Bus. , Helene Wells B.Soc.Sci. & Robert Kemp
a c
, Margot Legosz Ph.D.
b
a
Queensland Alcohol and Drug Research and Education Centre, School of Population Health, The University of Queensland , Herston , QLD , Australia b
Drug Harm Reduction Branch , Preventative Health Directorate, Queensland Health, Division of the Chief Health Officer , Herston , QLD , Australia c
School of Social Science, The University of Queensland , St Lucia , QLD , Australia
d
Crime and Misconduct Commission, St Pauls Terrace , Fortitude Valley , QLD , Australia Published online: 18 Nov 2013.
To cite this article: Andrew Smirnov B.A., G.Dip.Lib.Sci. , Jake M. Najman Ph.D. , Margot Legosz Ph.D. M.P.H. Dip.Bus. , Helene Wells B.Soc.Sci. & Robert Kemp (2013) Social Contacts and Ecstasy Offers: Findings of a Population-Based Study, Journal of Psychoactive Drugs, 45:5, 425-433, DOI: 10.1080/02791072.2013.845708 To link to this article: http://dx.doi.org/10.1080/02791072.2013.845708
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Journal of Psychoactive Drugs, 45 (5), 425–433, 2013 Copyright © Taylor & Francis Group, LLC ISSN: 0279-1072 print / 2159-9777 online DOI: 10.1080/02791072.2013.845708
Social Contacts and Ecstasy Offers: Findings of a Population-Based Study
Downloaded by [Laurentian University] at 04:39 05 October 2014
Andrew Smirnov, B.A., G.Dip.Lib.Sci.a,b ; Jake M. Najman, Ph.D.a,c ; Margot Legosz, Ph.D., M.P.H., Dip.Bus.d ; Helene Wells, B.Soc.Sci.d & Robert Kempb
Abstract — Ecstasy (MDMA) use is relatively common among young adults in many developed countries. However, little is known about how young non-users are first introduced to Ecstasy, including the relative contribution of peer networks and individual risk factors. We assess the role of social contact with Ecstasy-using peers in regard to young adults’ exposure to offers of Ecstasy, using data from the Natural History Study, a population-based study conducted in Australia. Population screening of young adults (19- to 23-year-olds) identified a sample of young Ecstasy users (N = 315) and a comparison group of Ecstasy-naïve participants (N = 199). Two outcomes are considered: being exposed to any Ecstasy offers and being exposed to > 3 offers. Extensive social contact with Ecstasy users was defined as knowing >10 Ecstasy users. Of the Ecstasy-naïve young adults, >40% had ever received Ecstasy offers. Extensive social contact with Ecstasy users independently predicted exposure to multiple (> 3) Ecstasy offers for Ecstasy-naïve young adults. These findings indicate that Ecstasy offers are widespread among users and non-users of Ecstasy. For non-users, exposure to Ecstasy offers occurs through social contact with drug-using peers independently of individual risk factors. The pervasiveness of Ecstasy offers suggests that universal education concerning Ecstasy use is required. Keywords — drug offers, drug use opportunity, Ecstasy (MDMA), social contact, young adults
Ecstasy (3,4-methylenedioxymethamphetamine or MDMA) is one of the most popular drugs among young adults in developed countries and use also appears to be increasing in developing countries (Degenhardt et al. 2009; Schifano et al. 2006; United Nations Office on Drugs and Crime 2010). Globally, users of amphetamine-type stimulants including Ecstasy and its analogues are estimated
to outnumber opiate and cocaine users combined. Despite this, the reasons for the considerable uptake of Ecstasy use among young people are poorly understood. Initial opportunities to use drugs are the first stage in the natural history of drug use. The study of “drug use opportunities” can provide valuable information concerning the transmission of drug use behavior and variation in the prevalence of drug-related problems within a population (Van Etten & Anthony 2001; Van Etten, Neumark & Anthony 1999). Despite the high global prevalence of Ecstasy use, previous studies concerning the prevalence of drug use opportunities have not included Ecstasy (Van Etten & Anthony 1999; Wells et al. 2011) and data on lifetime patterns of exposure, including the proportion of non-users ever exposed, are limited. Other etiological information concerning lifetime opportunities is also absent, including age of first exposure and the number of opportunities ever received (Australian Institute of Health and Welfare 2011).
a Queensland Alcohol and Drug Research and Education Centre, School of Population Health, The University of Queensland, Herston, QLD, Australia. b Drug Harm Reduction Branch, Preventative Health Directorate, Queensland Health, Division of the Chief Health Officer, Herston, QLD, Australia. c School of Social Science, The University of Queensland, St Lucia, QLD, Australia. d Crime and Misconduct Commission, St Pauls Terrace, Fortitude Valley, QLD, Australia. Please address correspondence to Andrew Smirnov, QADREC, School of Population Health, The University of Queensland, Herston Rd, Herston, QLD, 4006, Australia; phone: +61-7-3365-5287 fax: +61-73365-5509 email: [email protected]
Journal of Psychoactive Drugs
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Volume 45 (5), November – December 2013
Downloaded by [Laurentian University] at 04:39 05 October 2014
Smirnov et al.
Social Contacts and Ecstasy Offers
Furthermore, we know little about factors leading to Ecstasy or other drug use opportunities for drug-naïve young adults. From the available evidence, exposure to opportunities might be increased by externalizing behaviors such as delinquency (Rosenberg & Anthony 2001), psychological distress (Liang et al. 2011), or social contact with drug-using peers (Benjet et al. 2007; Okamoto et al. 2010). While social contact with drug users is a prerequisite for exposure to drug use opportunities, the implications for prevention programs differ depending on whether this contact is purposefully sought rather than passive and incidental. Drug-seeking behavior is generally associated with a number of individual and environmental risk factors (Agar & Reisinger 2001; Degenhardt et al. 2010; Gillespie et al. 2007). However, passive encounters with drug use opportunities could occur by “chance” (i.e., via friends or acquaintances who happen to use that drug), particularly if the use of a drug is widespread (Van Etten & Anthony 1999; Van Etten, Neumark & Anthony 1997). This is especially relevant for early adulthood, during which peer networks are often extensive and may comprise many drug users (Arria et al. 2008; Gillespie et al. 2007; Parker, Williams & Aldridge 2002). Opportunities to use Ecstasy could also be facilitated by attendance at social recreational settings where Ecstasy use is likely to occur, although it is unclear whether these settings are instrumental in the transmission of opportunities (Boeri, Sterk & Elifson 2004; Eiserman, Diamond & Schensul 2005; Van Havere et al. 2011). Under these conditions, if social contact facilitated widespread exposure by chance, a risk factor approach to preventing exposure might be ineffectual. Previous studies have defined drug use opportunity as any situation in which the respondent perceived they could have used drugs if they had wished to (Australian Institute of Health and Welfare 2008a; Benjet et al. 2007; Gillespie et al. 2007; Van Etten & Anthony 1999). This definition may include instances where no offer of drugs is forthcoming. It may also include instances where opportunity is entirely the result of drug-seeking behavior. The high proportion of drug users who used at their first lifetime opportunity (Van Etten & Anthony 1999) underscores the possibility that some drug use initiates are actively seeking drugs. Definitions of opportunity that focus on offers to use drugs may provide a more accurate assessment of the extent of transmission of drug use by drug users to their peers. However, few studies have focused on “drug offers” (Moon et al. 1999; Okamoto et al. 2010; Vervaeke, Benschop & Korf 2008). The Natural History Study of Drug Use examines offers of Ecstasy received by young adults. We compare Ecstasy-naïve with Ecstasy-using young adults in regard to the prevalence of Ecstasy use offers and related factors. Furthermore, we examine predictors of Ecstasy use opportunities among Ecstasy-naïve young adults in terms Journal of Psychoactive Drugs
of social contact with Ecstasy users, involvement in recreational settings, prior drug use, early deviance, and psychological distress. We define drug use opportunity in terms of drug offers so that we can assess the active role of peers in facilitating drug use.
METHODS Participants The Natural History Study Drug Use is a populationbased retrospective/prospective longitudinal study of a young adult cohort comprising amphetamine-type stimulant (ATS) users and a comparison group (CG) of nonusers. We used a novel application of population screening, using electoral roll data to create a population-based probability sample of young drug users and non-users. Voting is compulsory in Australia for all citizens aged 18 years and over. In June 2008, an estimated 82% of eligible 18to 25-year-olds were registered on the Australian electoral roll (Australian Electoral Commission 2008). A questionnaire was mailed to 19- to 23-year-olds randomly selected from electoral roll data for Brisbane and the Gold Coast (Australia). The 19- to 23-year age group was chosen because ATS use tends to commence at this age (Australian Institute of Health and Welfare 2008a; Chen et al. 2003; von Sydow et al. 2002). The screening response rate was 49.9% (N = 12,079). Respondents who reported they had used Ecstasy and/or methamphetamine at least three times in the preceding year were eligible for inclusion in the study as ATS users. This threshold was chosen to exclude “experimental” users. From 6029 responses, 522 (8.7%) met this inclusion criterion; a higher proportion of respondents were eligible based on their Ecstasy use (8%) than on their methamphetamine use (3%). In addition, 4682 (77.7%) had never used Ecstasy or methamphetamine (i.e., they were ATS-naïve). Of eligible ATS users, 352 (67.4%) were contactable and agreed to participate. Of ATS-naïve respondents, 320 were randomly selected for participation in the CG and 204 (63.8%) participated. A follow-up Internet survey conducted six months after baseline was completed by 95.2% of ATS users and 97.6% of CG participants. For the present study, we focus on the CG (N = 199) and Ecstasy-using participants (N = 315) for whom we have complete data; the Ecstasy-using group comprises participants who were eligible for the study on the basis of their Ecstasy use (i.e., participants eligible only on the basis of their methamphetamine use are excluded). All participants provided informed consent and the study was approved by the University of Queensland Behavioural and Social Sciences Ethical Review Committee. 426
Volume 45 (5), November – December 2013
Smirnov et al.
Social Contacts and Ecstasy Offers
MEASURES
assessed using the nonparametric two-sample Wilcoxon rank-sum test. For CG participants, the relative risk of receiving Ecstasy offers was considered in relation to selected risk variables. The proportional odds assumption for ordinal regression was violated; different relationships were present among the outcome groups; i.e., (1) no offers; (2) 1-3 offers; and (3) more than three offers. Consequently, separate logistic regression was conducted for each comparison (i.e., 1 vs. 2 + 3 and 1 + 2 vs. 3). The prediction model was restricted to CG participants, as most Ecstasyusing participants had being offered Ecstasy. Logistic regression was conducted with adjustment for all variables. Being offered Ecstasy was a common outcome (> 10% of each gender in the CG were offered), and consequently odds ratios were corrected to obtain an approximation of the true relative risk (McNutt, Hafner & Xue 1999; Zhang & Yu 1998). The univariable estimates of risk were consistent with those obtained from log-binomial regression. Data were analyzed using Stata Special Edition 11.0.
Downloaded by [Laurentian University] at 04:39 05 October 2014
Drug Use Offers Retrospective questions addressed drug offers made to the participant (e.g., “Has anyone EVER offered you Ecstasy, regardless of whether you accepted or declined this offer?”). We also asked participants how many times they were offered before they first used. For Ecstasynaïve participants, this amounted to the total number of Ecstasy offers ever received. We created a variable to indicate three different outcome levels in regard to Ecstasy offers (0 offers, 1-3 offers, >3 offers). Receiving 1-3 offers could be described as infrequent or chance exposure, while receiving more than three offers is suggestive of frequent or systemic exposure. Social Contacts Participants were asked how many Ecstasy users and methamphetamine users they knew by name or face. Knowing more than 10 Ecstasy users represented the upper quartile for CG participants, and was designated as having a large set of Ecstasy-using social contacts.
RESULTS Recreational Settings We asked participants about social or recreational venues they visited during the previous 12 months. To distinguish between different cultural settings where music is performed, we consider attendance at music festivals or electronic/dance music events compared with attendance at live music venues; festivals and electronic music events have tended to be more closely associated with Ecstasy use than venues such as pubs and bars where live music is performed. These questions were asked at the six-month follow-up, but address a time period comparable to other measures, given the 12-month timeframe.
Study Group Characteristics The proportions of each study group exposed to various risk factors are presented in Table 1. Comparison group (CG) participants differed from Ecstasy users in all respects, except for levels of psychological distress. Having extensive social contact with Ecstasy users (i.e., knowing >10 Ecstasy users) characterized the Ecstasy-using group. Interestingly, a considerable minority of persons in the CG (about one in six) also reported having extensive social contact with Ecstasy users. While Ecstasy users were more likely than the CG to have attended electronic music events (including music festivals), differences in attendance at live music venues were relatively modest.
Psychological Distress Psychological distress was evaluated using the Hospital Anxiety Depression Scale (HADS; Zigmond & Snaith 1983). The total scale provides a valid and reliable screen for psychological distress (Costantini et al. 1999; Herrmann 1997) with a Cronbach’s alpha of 0.88 to 0.89 (Costantini et al. 1999). The HADS is suited to identifying psychological distress in illicit drug users because it does not refer to somatic symptoms (Sumnall & Cole 2005; Verheyden, Henry & Curran 2003). A cut-off of 14 indicates high levels of distress (Bjelland et al. 2002; Crawford et al. 2001).
Drug Offers Ecstasy users vs. the comparison group. Table 2 provides details of participants’ reports of being offered Ecstasy and the age of first offers. The level of exposure to Ecstasy offers was greater for the Ecstasy users than the CG participants. However, the degree of exposure within the CG was surprisingly high. More than 40% of CG participants had ever been offered Ecstasy, and more than one in five had been offered on three or more occasions (and evidently had declined offers on the same number of occasions). For the Ecstasy-using group, we only counted the number of Ecstasy offers received up until the first occasion of Ecstasy use. Most Ecstasy-using participants had been offered Ecstasy before they used for the first time, and around a third experienced systemic exposure to
Data Analysis Differences between study group proportions reporting risk factor exposure and drug offers were analyzed using Pearson’s chi-square. Ages of first drug offers were not normally distributed and consequently differences were Journal of Psychoactive Drugs
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Volume 45 (5), November – December 2013
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Social Contacts and Ecstasy Offers
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TABLE 1 Study Group Characteristics: Comparison Group (CG) and Ecstasy-using Participants, by Sexa
Know > 10 Ecstasy users Males Females Attended festival (last 12 months)c Males Females Attended live venue (last 12 months)d Males Females Ever used cannabis Males Females First used alcohol aged < 15 years Males Females School suspension (ever) Males Females Recent psychological distresse Males Females
CG
Ecstasy users
p-valueb
21.3 (80) 14.3 (119)
91.5 (153) 90.1 (162)
Journal of Psychoactive Drugs Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ujpd20
Social Contacts and Ecstasy Offers: Findings of a Population-Based Study Andrew Smirnov B.A., G.Dip.Lib.Sci.
a b
, Jake M. Najman Ph.D.
d
d
M.P.H. Dip.Bus. , Helene Wells B.Soc.Sci. & Robert Kemp
a c
, Margot Legosz Ph.D.
b
a
Queensland Alcohol and Drug Research and Education Centre, School of Population Health, The University of Queensland , Herston , QLD , Australia b
Drug Harm Reduction Branch , Preventative Health Directorate, Queensland Health, Division of the Chief Health Officer , Herston , QLD , Australia c
School of Social Science, The University of Queensland , St Lucia , QLD , Australia
d
Crime and Misconduct Commission, St Pauls Terrace , Fortitude Valley , QLD , Australia Published online: 18 Nov 2013.
To cite this article: Andrew Smirnov B.A., G.Dip.Lib.Sci. , Jake M. Najman Ph.D. , Margot Legosz Ph.D. M.P.H. Dip.Bus. , Helene Wells B.Soc.Sci. & Robert Kemp (2013) Social Contacts and Ecstasy Offers: Findings of a Population-Based Study, Journal of Psychoactive Drugs, 45:5, 425-433, DOI: 10.1080/02791072.2013.845708 To link to this article: http://dx.doi.org/10.1080/02791072.2013.845708
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Journal of Psychoactive Drugs, 45 (5), 425–433, 2013 Copyright © Taylor & Francis Group, LLC ISSN: 0279-1072 print / 2159-9777 online DOI: 10.1080/02791072.2013.845708
Social Contacts and Ecstasy Offers: Findings of a Population-Based Study
Downloaded by [Laurentian University] at 04:39 05 October 2014
Andrew Smirnov, B.A., G.Dip.Lib.Sci.a,b ; Jake M. Najman, Ph.D.a,c ; Margot Legosz, Ph.D., M.P.H., Dip.Bus.d ; Helene Wells, B.Soc.Sci.d & Robert Kempb
Abstract — Ecstasy (MDMA) use is relatively common among young adults in many developed countries. However, little is known about how young non-users are first introduced to Ecstasy, including the relative contribution of peer networks and individual risk factors. We assess the role of social contact with Ecstasy-using peers in regard to young adults’ exposure to offers of Ecstasy, using data from the Natural History Study, a population-based study conducted in Australia. Population screening of young adults (19- to 23-year-olds) identified a sample of young Ecstasy users (N = 315) and a comparison group of Ecstasy-naïve participants (N = 199). Two outcomes are considered: being exposed to any Ecstasy offers and being exposed to > 3 offers. Extensive social contact with Ecstasy users was defined as knowing >10 Ecstasy users. Of the Ecstasy-naïve young adults, >40% had ever received Ecstasy offers. Extensive social contact with Ecstasy users independently predicted exposure to multiple (> 3) Ecstasy offers for Ecstasy-naïve young adults. These findings indicate that Ecstasy offers are widespread among users and non-users of Ecstasy. For non-users, exposure to Ecstasy offers occurs through social contact with drug-using peers independently of individual risk factors. The pervasiveness of Ecstasy offers suggests that universal education concerning Ecstasy use is required. Keywords — drug offers, drug use opportunity, Ecstasy (MDMA), social contact, young adults
Ecstasy (3,4-methylenedioxymethamphetamine or MDMA) is one of the most popular drugs among young adults in developed countries and use also appears to be increasing in developing countries (Degenhardt et al. 2009; Schifano et al. 2006; United Nations Office on Drugs and Crime 2010). Globally, users of amphetamine-type stimulants including Ecstasy and its analogues are estimated
to outnumber opiate and cocaine users combined. Despite this, the reasons for the considerable uptake of Ecstasy use among young people are poorly understood. Initial opportunities to use drugs are the first stage in the natural history of drug use. The study of “drug use opportunities” can provide valuable information concerning the transmission of drug use behavior and variation in the prevalence of drug-related problems within a population (Van Etten & Anthony 2001; Van Etten, Neumark & Anthony 1999). Despite the high global prevalence of Ecstasy use, previous studies concerning the prevalence of drug use opportunities have not included Ecstasy (Van Etten & Anthony 1999; Wells et al. 2011) and data on lifetime patterns of exposure, including the proportion of non-users ever exposed, are limited. Other etiological information concerning lifetime opportunities is also absent, including age of first exposure and the number of opportunities ever received (Australian Institute of Health and Welfare 2011).
a Queensland Alcohol and Drug Research and Education Centre, School of Population Health, The University of Queensland, Herston, QLD, Australia. b Drug Harm Reduction Branch, Preventative Health Directorate, Queensland Health, Division of the Chief Health Officer, Herston, QLD, Australia. c School of Social Science, The University of Queensland, St Lucia, QLD, Australia. d Crime and Misconduct Commission, St Pauls Terrace, Fortitude Valley, QLD, Australia. Please address correspondence to Andrew Smirnov, QADREC, School of Population Health, The University of Queensland, Herston Rd, Herston, QLD, 4006, Australia; phone: +61-7-3365-5287 fax: +61-73365-5509 email: [email protected]
Journal of Psychoactive Drugs
425
Volume 45 (5), November – December 2013
Downloaded by [Laurentian University] at 04:39 05 October 2014
Smirnov et al.
Social Contacts and Ecstasy Offers
Furthermore, we know little about factors leading to Ecstasy or other drug use opportunities for drug-naïve young adults. From the available evidence, exposure to opportunities might be increased by externalizing behaviors such as delinquency (Rosenberg & Anthony 2001), psychological distress (Liang et al. 2011), or social contact with drug-using peers (Benjet et al. 2007; Okamoto et al. 2010). While social contact with drug users is a prerequisite for exposure to drug use opportunities, the implications for prevention programs differ depending on whether this contact is purposefully sought rather than passive and incidental. Drug-seeking behavior is generally associated with a number of individual and environmental risk factors (Agar & Reisinger 2001; Degenhardt et al. 2010; Gillespie et al. 2007). However, passive encounters with drug use opportunities could occur by “chance” (i.e., via friends or acquaintances who happen to use that drug), particularly if the use of a drug is widespread (Van Etten & Anthony 1999; Van Etten, Neumark & Anthony 1997). This is especially relevant for early adulthood, during which peer networks are often extensive and may comprise many drug users (Arria et al. 2008; Gillespie et al. 2007; Parker, Williams & Aldridge 2002). Opportunities to use Ecstasy could also be facilitated by attendance at social recreational settings where Ecstasy use is likely to occur, although it is unclear whether these settings are instrumental in the transmission of opportunities (Boeri, Sterk & Elifson 2004; Eiserman, Diamond & Schensul 2005; Van Havere et al. 2011). Under these conditions, if social contact facilitated widespread exposure by chance, a risk factor approach to preventing exposure might be ineffectual. Previous studies have defined drug use opportunity as any situation in which the respondent perceived they could have used drugs if they had wished to (Australian Institute of Health and Welfare 2008a; Benjet et al. 2007; Gillespie et al. 2007; Van Etten & Anthony 1999). This definition may include instances where no offer of drugs is forthcoming. It may also include instances where opportunity is entirely the result of drug-seeking behavior. The high proportion of drug users who used at their first lifetime opportunity (Van Etten & Anthony 1999) underscores the possibility that some drug use initiates are actively seeking drugs. Definitions of opportunity that focus on offers to use drugs may provide a more accurate assessment of the extent of transmission of drug use by drug users to their peers. However, few studies have focused on “drug offers” (Moon et al. 1999; Okamoto et al. 2010; Vervaeke, Benschop & Korf 2008). The Natural History Study of Drug Use examines offers of Ecstasy received by young adults. We compare Ecstasy-naïve with Ecstasy-using young adults in regard to the prevalence of Ecstasy use offers and related factors. Furthermore, we examine predictors of Ecstasy use opportunities among Ecstasy-naïve young adults in terms Journal of Psychoactive Drugs
of social contact with Ecstasy users, involvement in recreational settings, prior drug use, early deviance, and psychological distress. We define drug use opportunity in terms of drug offers so that we can assess the active role of peers in facilitating drug use.
METHODS Participants The Natural History Study Drug Use is a populationbased retrospective/prospective longitudinal study of a young adult cohort comprising amphetamine-type stimulant (ATS) users and a comparison group (CG) of nonusers. We used a novel application of population screening, using electoral roll data to create a population-based probability sample of young drug users and non-users. Voting is compulsory in Australia for all citizens aged 18 years and over. In June 2008, an estimated 82% of eligible 18to 25-year-olds were registered on the Australian electoral roll (Australian Electoral Commission 2008). A questionnaire was mailed to 19- to 23-year-olds randomly selected from electoral roll data for Brisbane and the Gold Coast (Australia). The 19- to 23-year age group was chosen because ATS use tends to commence at this age (Australian Institute of Health and Welfare 2008a; Chen et al. 2003; von Sydow et al. 2002). The screening response rate was 49.9% (N = 12,079). Respondents who reported they had used Ecstasy and/or methamphetamine at least three times in the preceding year were eligible for inclusion in the study as ATS users. This threshold was chosen to exclude “experimental” users. From 6029 responses, 522 (8.7%) met this inclusion criterion; a higher proportion of respondents were eligible based on their Ecstasy use (8%) than on their methamphetamine use (3%). In addition, 4682 (77.7%) had never used Ecstasy or methamphetamine (i.e., they were ATS-naïve). Of eligible ATS users, 352 (67.4%) were contactable and agreed to participate. Of ATS-naïve respondents, 320 were randomly selected for participation in the CG and 204 (63.8%) participated. A follow-up Internet survey conducted six months after baseline was completed by 95.2% of ATS users and 97.6% of CG participants. For the present study, we focus on the CG (N = 199) and Ecstasy-using participants (N = 315) for whom we have complete data; the Ecstasy-using group comprises participants who were eligible for the study on the basis of their Ecstasy use (i.e., participants eligible only on the basis of their methamphetamine use are excluded). All participants provided informed consent and the study was approved by the University of Queensland Behavioural and Social Sciences Ethical Review Committee. 426
Volume 45 (5), November – December 2013
Smirnov et al.
Social Contacts and Ecstasy Offers
MEASURES
assessed using the nonparametric two-sample Wilcoxon rank-sum test. For CG participants, the relative risk of receiving Ecstasy offers was considered in relation to selected risk variables. The proportional odds assumption for ordinal regression was violated; different relationships were present among the outcome groups; i.e., (1) no offers; (2) 1-3 offers; and (3) more than three offers. Consequently, separate logistic regression was conducted for each comparison (i.e., 1 vs. 2 + 3 and 1 + 2 vs. 3). The prediction model was restricted to CG participants, as most Ecstasyusing participants had being offered Ecstasy. Logistic regression was conducted with adjustment for all variables. Being offered Ecstasy was a common outcome (> 10% of each gender in the CG were offered), and consequently odds ratios were corrected to obtain an approximation of the true relative risk (McNutt, Hafner & Xue 1999; Zhang & Yu 1998). The univariable estimates of risk were consistent with those obtained from log-binomial regression. Data were analyzed using Stata Special Edition 11.0.
Downloaded by [Laurentian University] at 04:39 05 October 2014
Drug Use Offers Retrospective questions addressed drug offers made to the participant (e.g., “Has anyone EVER offered you Ecstasy, regardless of whether you accepted or declined this offer?”). We also asked participants how many times they were offered before they first used. For Ecstasynaïve participants, this amounted to the total number of Ecstasy offers ever received. We created a variable to indicate three different outcome levels in regard to Ecstasy offers (0 offers, 1-3 offers, >3 offers). Receiving 1-3 offers could be described as infrequent or chance exposure, while receiving more than three offers is suggestive of frequent or systemic exposure. Social Contacts Participants were asked how many Ecstasy users and methamphetamine users they knew by name or face. Knowing more than 10 Ecstasy users represented the upper quartile for CG participants, and was designated as having a large set of Ecstasy-using social contacts.
RESULTS Recreational Settings We asked participants about social or recreational venues they visited during the previous 12 months. To distinguish between different cultural settings where music is performed, we consider attendance at music festivals or electronic/dance music events compared with attendance at live music venues; festivals and electronic music events have tended to be more closely associated with Ecstasy use than venues such as pubs and bars where live music is performed. These questions were asked at the six-month follow-up, but address a time period comparable to other measures, given the 12-month timeframe.
Study Group Characteristics The proportions of each study group exposed to various risk factors are presented in Table 1. Comparison group (CG) participants differed from Ecstasy users in all respects, except for levels of psychological distress. Having extensive social contact with Ecstasy users (i.e., knowing >10 Ecstasy users) characterized the Ecstasy-using group. Interestingly, a considerable minority of persons in the CG (about one in six) also reported having extensive social contact with Ecstasy users. While Ecstasy users were more likely than the CG to have attended electronic music events (including music festivals), differences in attendance at live music venues were relatively modest.
Psychological Distress Psychological distress was evaluated using the Hospital Anxiety Depression Scale (HADS; Zigmond & Snaith 1983). The total scale provides a valid and reliable screen for psychological distress (Costantini et al. 1999; Herrmann 1997) with a Cronbach’s alpha of 0.88 to 0.89 (Costantini et al. 1999). The HADS is suited to identifying psychological distress in illicit drug users because it does not refer to somatic symptoms (Sumnall & Cole 2005; Verheyden, Henry & Curran 2003). A cut-off of 14 indicates high levels of distress (Bjelland et al. 2002; Crawford et al. 2001).
Drug Offers Ecstasy users vs. the comparison group. Table 2 provides details of participants’ reports of being offered Ecstasy and the age of first offers. The level of exposure to Ecstasy offers was greater for the Ecstasy users than the CG participants. However, the degree of exposure within the CG was surprisingly high. More than 40% of CG participants had ever been offered Ecstasy, and more than one in five had been offered on three or more occasions (and evidently had declined offers on the same number of occasions). For the Ecstasy-using group, we only counted the number of Ecstasy offers received up until the first occasion of Ecstasy use. Most Ecstasy-using participants had been offered Ecstasy before they used for the first time, and around a third experienced systemic exposure to
Data Analysis Differences between study group proportions reporting risk factor exposure and drug offers were analyzed using Pearson’s chi-square. Ages of first drug offers were not normally distributed and consequently differences were Journal of Psychoactive Drugs
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Smirnov et al.
Social Contacts and Ecstasy Offers
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TABLE 1 Study Group Characteristics: Comparison Group (CG) and Ecstasy-using Participants, by Sexa
Know > 10 Ecstasy users Males Females Attended festival (last 12 months)c Males Females Attended live venue (last 12 months)d Males Females Ever used cannabis Males Females First used alcohol aged < 15 years Males Females School suspension (ever) Males Females Recent psychological distresse Males Females
CG
Ecstasy users
p-valueb
21.3 (80) 14.3 (119)
91.5 (153) 90.1 (162)
