Design
A two-group randomized controlled trial will be used. The intervention group will receive an internet intervention consisting of three modules (detailed below). The wait-list control group will undertake the same assessments as the intervention group, with access to the intervention site at 6 months post enrolment. In addition, all participants will be provided with contact details for emergency services.
Sample
Participants will be recruited via a variety of sources: youth magazines, web-sites, social networking sites, universities and clinics. The inclusion criteria are: resident in Australia, aged 18 years or older and use of amphetamine type stimulants (e.g. meth/amphetamine, ecstasy, non-medical use of prescription stimulants) in the last 3 months. Furthermore, participants need to have access to the internet, a valid e-mail address, telephone access and to provide informed consent. The exclusion criteria are: currently receiving any treatment for stimulant abuse/dependence, currently receiving pharmacotherapy for any substance use disorder (e.g. methadone, naltrexone, buprenorphine) except nicotine replacement therapy; self-reported lifetime diagnosis with schizophrenia, schizoaffective, or bipolar disorder.
Procedure
Enrolment and screening will be undertaken via the internet. Advertisements will direct participants to the study web address. First, participants who visit the study website will be given information on the project and their eligibility assessed by means of a series of online questions. Based on their answers, participants who are not eligible for the study will be given information about other potentially useful websites and resources (e.g. mental health, alcohol or other drugs websites and helplines). Participants who are eligible for inclusion will be asked to provide active consent by ‘clicking’ on a box for each element of the consent form in order to enroll in the study. Figure1 illustrates the flow of participants through the study. Participants will be asked to provide an e-mail address that will be verified via a personalized link in an automated email. This link will take participants to the study site where they will set their own username and password. Participants will then be directed to an online baseline survey before being randomized to study groups. The randomization process will be fully automated with permuted blocks of four and will be implemented within the program.
Participants who are assigned to the intervention group will then be provided with immediate access to the first module of the intervention. These participants will be advised to allow 1 week between modules, but are allowed to proceed at their own pace. Participants must visit each page of a module in sequence to complete the module and thus obtain access to the next one. The intervention group will receive emails at seven day intervals after the commencement of the trial period, either asking them to start the next module, if they have not already commenced that module, or inviting them to revisit the site. A further e-mail will be sent to those who do not start the current module at 3 days after the module was scheduled for commencement. Participants will be invited via e-mail to complete follow-up assessment at 3 and 6 months (91 and 183 days) post-randomization with a further two reminder emails at 7 day intervals if required, followed by a telephone call(s) for participants who do not respond to the emails. Participants will receive AU$20 for baseline assessment and for each follow-up questionnaire that they complete, paid as either on-line vouchers or posted cheques.
The Australian National University Human Research Ethics committee approved the study, which is also registered with the Australian and New Zealand Clinical Trials Registry (http://www.anzctr.org.au/) ACTRN12611000947909.
Measures
Both the primary and secondary outcome measures will be assessed at baseline, 3 and 6 month. The primary outcome measure will be ATS use, assessed using the World Health Organization Alcohol, Smoking, Substance Involvement Screening Test (ASSIST) [28, 29]. The ASSIST first assesses lifetime use of nine categories of drugs (i.e. tobacco, alcohol, cannabis, cocaine, ATS, inhalants, sedatives, hallucinogens, opioids and other). Then, for any drug identified by the lifetime question, data relating to the last 3 months is collected on: frequency of use, cravings, problems (health, social legal or financial), and failure to fulfill roles. Next, the ASSIST ascertains if a friend or relative has ever expressed concern about their drug use and if the person has ever tried and failed to control their drug use. Finally, injection of drugs is assessed. The standard ASSIST scoring algorithm will be used to generate a score related to use of ATS [28].
The secondary outcomes will be: (a) health-seeking intention and help-seeking behavior measured with the general help-seeking questionnaire (GHSQ) [30] and the actual help-seeking questionnaire (AHSQ) [31, 32]; (b) readiness to change assessed using a modified version of the Readiness to Change Questionnaire (RTCQ) [33] referencing ATS rather than alcohol; (c) psychological distress assessed using the Kessler 10 [34]; (d) poly-drug use measured by the ASSIST [28]; (e) days out of role [35]; and (f) quality of life assessed by the European Health Interview Survey (EUROHIS) Quality of Life scale [36]. The baseline measures include demographic information (e.g., age, sex, marital status), drug use history (age of first use of ATS), and severity of dependence assessed using the Severity of Dependence Scale [37].
Both the GHSQ and AHSQ are designed to be modified to reflect the condition under investigation and relevant potential sources of help [32]. The condition investigated will be help-seeking for ‘a problem with stimulant drug use’, with additions to the existing list of potential sources of help including “drug information services (e.g. internet, telephone)” and “specialist drug services (e.g. in-person services)”. We will also modify examples such as “school counselor” or “teacher” to reflect the target age group (“counselor” or “lecturer”). Item scores will be summed on the two measures. The RTCQ has 12 items, with four questions relating to each of the stages: ‘pre-contemplation’; ‘contemplation’; and ‘action’. The five point Likert scales will be summed to obtain scores on each stage, with participants designated to their highest scoring stage, or in the event to tied scores, the higher stage [33]. The K10 total score (maximum 50) will be used to quantify psychological distress at each time point [34]. Poly-drug use will be defined as the sum of ASSIST classes of drugs endorsed for the past 3 months [29]. ‘Days out of role’ will be derived from Kessler’s questions but referencing “ATS drug use (e.g. methamphetamine, ecstasy, ice) “rather than “depression” [35] and quality of life will be indexed as total EUROHIS Quality of Life scores [36].
In addition, immediately after finishing the third module, the intervention group will evaluate the intervention content and study website. Satisfaction with the intervention plus perceived benefits and negative aspects will be assessed with a measure developed for the Wellbeing study [38] but modified to reference “drug use” rather than “depression”. Descriptive measures of completion (e.g. number of modules and subsequently, follow-up surveys) will be collected together with scores on the Internet Intervention Adherence Questionnaire – 16 items evaluating barriers to internet treatment [39]. Table 1 provides a summary of the measures assessed at each time point.
Estimation of the expected effect sizes and sample size
With three time points (baseline, 3 and 6 months) the study is designed to detect an effect of f = .27. This requires 60 people per group: to allow for attrition of 20% by 6 months we will recruit 80 people per group. The development study for the ASSIST reported that in an Australian sample of stimulant users, there was a significant group by time interaction for those who received a brief intervention compared to controls (with 64 and 65 people respectively per group), which had a power of 84% to detect this effect [28]. Other brief in-person motivational interventions have achieved moderate sized effects on drug use measures (d = .63-.45) [40], so the effect size postulated for this study is plausible.
Analysis
The primary analysis will be on an intention-to-treat basis, using a mixed model repeated measures (MMRM) approach. This overcomes many of the limitations of traditional repeated measures analysis of variance, in that it uses all available data without requiring substitution or estimation of missing values to avoid the exclusion of cases with non-complete data and does not assume homogeneity of correlations over waves of measurement [41]. The effect of the intervention will be assessed by an analysis of a time by group interaction. A sensitivity analysis will be conducted using multiple imputation of missing data. Categorical outcome measures will be evaluated using non-linear mixed models.
Content of modules
The theoretical approach reflected in the intervention modules is motivational enhancement with use of CBT based methods. The intervention draws on guidelines for face-to-face treatment of amphetamine use [42]. The underpinning philosophy is that of harm minimization, with participants free to decide on the most appropriate goals for themselves, including quitting completely, reducing their drug use, taking a break from use, or using in a less hazardous manner.
The first module examines the key problem areas on which the use of ATS typically impacts. Participants either select from a menu of items for each problem area or record relevant problems that they have incurred. The areas are: relationships with family and friends, health, finances, work/study, legal issues, mental health, and specific drug use problems (see Figure2). Each page of the intervention features four characters, with a developing storyline for each character that involves a problem relevant to that page; for example, problems that have arisen in a work setting. The final page provides a summary of the problems that the participant has endorsed and guides the participant to generate a ‘map’ of the interconnections between problems.
Module two asks participants to think about the pros and cons of their use of stimulants and the good and bad things related to changing their behavior, an approach based on the model of Miller and Rollnick [43]. To aid in their ‘decision balance’ for each good or bad element that they select, participants are asked to rate its importance on a 1-10 scale (see Figure3).
The third module focuses on behavioral change including techniques such as setting clearly specified goals, actions on specific dates, strategies to help with controlling and overcoming cravings, refusal skills, managing a ‘slip’, and an action plan to deal with high risk situations.
Safety & security
The intervention is not intended to provide emergency treatment, and the participant information sheet and website for the study provide emergency contact numbers for appropriate providers. If distressed participants contact the research team, the Centre for Mental Health Research has a written protocol to guide members of staff in handling the situation. All user data collected via the study website and the online intervention are securely stored according to a written protocol, and access to data is limited to research staff who are named on the ethics protocol [44].