Ethical approval and compensation
This study, including the methods and design, was approved by the University of Calgary
Conjoint Faculties Research Ethics Board (CFREB), REB20-0568. Any modifications to the protocol, including changes to the objectives, design, sample size, or study procedures, will be agreed upon by all investigators and submitted for ethical review and approval prior to implementation. Participants will be financially compensated an electronic gift card valued at CAD $10 following: 1) confirmation of eligibility; 2) completion of the baseline assessment; 3) creation of an account with the online self-help program; and 4) completion of a motivational interview (if assigned to that group). Participants will also be remunerated with an electronic gift card valued at CAD $30 after each of four follow-up assessments have been completed in full; in total, participants could receive CAD $130 in electronic gift cards. Participants will have the ability to choose electronic gift card(s) from a number of local stores and restaurants.
Anonymity cannot be guaranteed, due to the use of email addresses (for online accounts and e- gift card compensation) and names to match interview data with online data. At the outset, participant data will be linked via personal information provided. Data from the online workbook will be linked with personal and survey data via unique participant identification numbers. Participants will be informed of these limits to anonymity during the consent process. After all data has been linked and participants have been compensated, personally identifying information (in a master spreadsheet) will be permanently deleted, with the exception of age and sex. This will leave only the anonymized data in an SPSS file. Participant data will be kept completely confidential unless there is: 1) risk of harm to self or others (e.g., suicidal plans) or 2) court-ordered subpoena/other legal demands for data. If there is high risk to self or others, participants will be informed that the researchers or graduate students conducting MI sessions may contact local authorities or medical services to prevent harm.
Participant recruitment and randomisation
Participants will be recruited via targeted internet advertisements (i.e., “Are you concerned about your gambling? Study includes free and confidential online help for your gambling”). These advertisements will be distributed online (e.g., Facebook; Kijiji; YouTube; Google; Twitter; Reddit) to media users across Canada. To meet eligibility requirements, participants must: a) be a Canadian resident; b) be 18 years of age or older; c) have gambled at least once within the last month; d) score 5 or more on the Problem Gambling Severity Index (PGSI) (20); and e) not currently be involved in treatment for their gambling. As with most prior gambling intervention trials, use of psychiatric medication will not be an exclusion criterion, but will not be assessed or monitored in this study.
Individuals who are interested will be directed from an advertisement to an online eligibility screening questionnaire on Qualtrics. Those who meet eligibility criteria will be asked to provide consent and contact information within Qualtrics, and then complete the baseline assessment. Once these steps have been completed, participants will be randomised to one of the two treatment groups. Following validation that these steps have been completed, the research team will contact participants and schedule a motivational interview session if they are assigned to that group. As previously mentioned, participants will not receive the initial compensation until the aforementioned steps have been completed. Participants who complete at least one but not all of these steps will be sent a maximum of two reminder emails. Eligible participants can choose to be informed of the results of the trial via email upon its completion. Regardless, any publications and presentations resulting from this trial will be agreed upon by all investigators.
Participant validation. Email and IP addresses associated with survey responses will be checked for duplicates to ensure each participant only completes each survey once. Additionally, a VPN block and reCAPTCHA system will be implemented within each survey to prevent the enrolment of ineligible and fake participants, respectively. Finally, a randomly selected PGSI question will be presented at the end of the eligibility questionnaire; only participants whose response to this question matches the corresponding question in the initial set of PGSI questions will be enroled.
This protocol has been developed in accordance with the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) statement. A randomised two-arm clinical trial will be conducted (see Figure 1; Additional file 1). Participants will be automatically randomised in a 1:1 ratio to one of two groups: an internet only (IO) control group or an internet plus motivational interview (IMI) group. Group randomisation will be computer-generated using the program MINIM (21) and stratified by sex (male; female; other), gambling severity (low-moderate; high), and whether they have been previously treated for their gambling (yes; no) based on stratification strategies used in prior trials (12–14). Gambling severity, for the purpose of randomisation, will be defined based on PGSI scores of low-moderate (score of less than 8) or severe (score of 8 or greater). Participants will be invited via email to complete follow-up assessments at 3-, 6-, 12-, and 24-months after their enrolment in the study.
Internet only (IO). This treatment group will be provided with access to an online workbook (www.gamblingselfhelp.com) based on a paper version mentioned earlier (10) that has demonstrated efficacy in multiple trials (11–14). It consists of cognitive-behavioural self-help tools to reduce problem gambling. These tools are organized into four modules: self-assessment, goal setting, goal implementation, and goal maintenance. The design of the modules allows for the provision of concise cognitive-behavioural strategies for controlling or abstaining from gambling. The activities within each module may be completed in any order and as many times as desired. None of the activities are mandatory. Participants will have unrestricted access to the site for the entire duration of the study in order to mimic other web resources as much as possible in terms of accessibility.
Internet plus motivational interview (IMI). This treatment group will be provided with the same access to the online workbook as those in the IO group, plus one brief (i.e., 30- to 60-minute) motivational interview delivered digitally through an online audioconferencing platform (i.e., Microsoft Teams) within the first two weeks of study enrolment. In the event that participants have difficulties with Microsoft Teams, interviews will be conducted via telephone. Participants who refuse the motivational interview will not be compensated with the initial gift card, but will be retained in this group and followed up with in accordance with an intention-to-treat approach (ITT). Motivational interviewing involves the assessment of a client’s readiness for change, followed by the facilitation of behavioural change by reducing ambivalence, building commitment, and eliciting reasons for change (22). Clinical psychology graduate students will be trained to conduct the motivational interviews and will be compensated with clinical credit hours. All calls will be digitally recorded. Twenty percent of the calls will be assessed for treatment fidelity using a treatment adherence checklist, and they will be rated by two independent raters for reliability. The adherence checklist covers a number of elements that are essential to include (e.g., asking for commitment) and not include (e.g., providing unsolicited advice) during the interview sessions.
Demographics. A variety of demographic questions used in previous gambling trial studies will be asked to screen for eligibility and gather descriptive information in regards to age, sex, education level, income, occupation, ethnicity, marital status, and types of gambling they engage in. They will also be asked whether or not they are currently receiving treatment for their gambling and if they have in the past.
Gambling severity. The PGSI (20) will be used to screen for gambling problems prior to study commencement. The PGSI is a 9-item scale used to assess problem gambling severity. Respondents answer a series of questions related to their gambling on a 4-point scale ranging from “never” to “almost always,” and total scores range from 0 to 27. While many prior trials have used a PGSI score of 3 as a cutoff, Currie, Hodgins, and Casey (23) determined that a cutoff score of 5 better differentiates low- from moderate-risk gamblers in terms of gambling expenditures. PGSI scores have been shown to correlate highly with other measures of gambling severity (r = .83), such as the National Opinion Research Center DSM-IV Screen for Gambling Problems (NODS). Additionally, the PGSI has demonstrated good internal consistency ( = .84) (20).
Baseline and follow-up assessments
Primary outcomes. Gambling frequency and expenditures. Prospective participants will also be asked to estimate the average number of hours they have gambled per month and per gambling session over the last three months, as well as the average amount of money they won or lost per month and per gambling session. These 3-month retrospective self-report questions were adapted from the Gambling Participation Instrument (GPI) (24).
Gambling severity. In addition to gambling frequency and expenditures, gambling severity will also be assessed. The NODS (25) is a 17-item measure that uses DSM-IV criteria to assess gambling problems. The 3-month version of the NODS has been previously validated as an outcome measure for gambling intervention research, demonstrating good internal consistency ( = .87) (26). It also correlates highly with other measures of gambling severity (r = .86) and moderately with number of days gambled and number of dollars spent (r = .50) (27).
Secondary outcomes. Depression symptoms. The Patient Health Questionnaire-9 (PHQ-9) (28) is a 9-item scale that measures symptoms of depression over the past two weeks. Item response options range from 0 (not at all) to 3 (nearly every day), yielding total scores that range from 0 to 27. The PHQ-9 has shown good internal consistency ( = .89) (28). Note that participants who endorse question 9 on the PHQ-9 (i.e., thoughts that they would be better off dead or hurting themselves in some way) will be directed to an automated response at the end of the survey; this response will encourage these participants to consult a resource (e.g., family physician) or contact a crisis helpline via phone numbers provided to them.
Anxiety symptoms. The Generalized Anxiety Scale-7 (GAD-7) (29) is a 7-item scale that measures symptoms of anxiety over the past two weeks. Each item is responded to using a 4-point Likert scale, and total GAD-7 scores range from 0 to 21. The GAD-7 has demonstrated excellent internal consistency ( = .92) (29).
General psychological distress. The Kessler Psychological Distress Scale-10 (K-10) (30) is a 10-item scale used to assess nonspecific psychological distress-related symptoms over the past four weeks. Response options span a 4-point scale ranging from “none of the time” to “all of the time,” and total scores range from 0 to 40. The K-10 has demonstrated high internal consistency ( = .78) (30).
Alcohol consumption. The Alcohol Use Disorder Identification Test – Consumption (AUDIT-C) (31) is a 3-item short-form of the full AUDIT that only measures alcohol consumption. Using a cut-off score of 3, the AUDIT-C has sensitivity of 98% and specificity of 57% for identifying active alcohol abuse or dependence (31).
Tertiary outcomes. Program evaluation. The Internet Evaluation and Utility Questionnaire (IEUQ) (32) is a 15-item scale used to measure participants’ experiences and perceptions of the online self-directed workbook. Questions include those related to ease of use, convenience, engagement, mode of delivery, and likelihood of returning. The IEUQ has demonstrated adequate internal consistency ( = .69) (32).
User data. In addition to the measures described above, user data will also be collected from the workbook website. These data will allow us to examine how much time participants spend on the site and individual modules, as well as which modules are in progress or completed, and the number of times participants logged on to access the online workbook.
Additional help-seeking. Upon completion of the treatment, participants will be asked to indicate whether or not they will seek further treatment or support for their gambling problems. They will also be asked to indicate what type, if any, that they intend on seeking. Options will include engagement in face-to-face therapy, attendance of support groups, and speaking to family or friends.
Participants will be informed during the consent process that they will be randomly assigned to one of the two intervention conditions. Neither intervention condition will be described as superior. Baseline assessment will occur prior to randomisation and follow-up assessments will occur after. Motivational interview sessions will be conducted after randomisation, so both participants and interviewers will be aware of participant assignment.
Sample size estimation
The sample size was determined based on previous work exploring self-directed gambling interventions (11–14) and was computed using G*Power (33) the basis of H1 and H2. The estimation method was based on a repeated-measures between-factors ANOVA, which serves as a simpler derivative of the general linear model that the primary analyses will be based on (34,35). Two superiority hypotheses using three primary outcome measures will be analyzed using conventional two-tailed tests with thresholds of power = .80 and = .05. Bonferroni corrections will be calculated to account for multiple comparisons. Correlations of r = .50 between baseline and follow-up data were accounted for (16). A sample size of 108 participants per group will permit statistical detection of small effect sizes (Cohen’s d = 0.20 for continuous measures) at the specified significance level. This translates to differential detection of approximately two days less gambling per month and a 1-point decrease in NODS scores (34). After accounting for 20% attrition over 12 months, the resulting planned sample size is 270 participants.
All statistical analyses will be conducted using SPSS version 26.0 at 12- and 24-month follow-up time points. Following completion of the 24-month follow-ups, the trial will be terminated. If baseline data are missing completely at random, they will be handled using the full imputation maximum likelihood approach to estimate means, variances, and covariances. Missing data at follow-ups will be handled using the intention-to-treat (ITT) approach. Bivariate comparisons of all demographics and outcome measures will be conducted to explore differences between groups at baseline. Chi-square tests of independence will be used to compare groups on categorical measures, while t-tests will be used to compare groups on continuous measures. Any primary outcome variables with significant differences between groups will be controlled for by entering them in as covariates in primary and secondary analyses. It is likely that the primary outcome variables will appear non-normally distributed when assessed with q-q plots and Shapiro-Wilk tests; in these cases, data will be appropriately transformed to achieve normality. If the data transformations are unsuccessful, separate nonparametric analyses will be conducted as appropriate instead of the respective planned analyses outlined below. Additionally, chi-square tests of independence will be used to determine if attrition rates differ in terms of treatment group or baseline characteristics.
H1 and H2 will be analyzed using generalized equation estimation (GEE) to determine if there are group (IO; IMI) differences in change over time. Outcome variables will include gambling frequency (i.e., number of days gambled in the last month), expenditures (i.e., average number of dollars lost per gambling day, and severity (i.e., NODS score). GEE is advantageous because it can account for the natural correlations over time in longitudinal data (35).
To aid in clinical significance and translation, H1 and H2 will also be analyzed categorically with two separate logistic regressions. Both analyses will include Group and Time as binary predictors. The analysis to test H1 will include gambling disorder status (meets criteria; does not meet criteria) as the binary outcome. The analysis to test H2 will include recovery status (abstinence; improvement; no improvement) as the multinomial outcome. Improvement is defined as at least a 50% reduction in average number of dollars lost per gambling session.
H3 will be analyzed with a bivariate Pearson correlation between time spent on the site and change in dollars spent per gambling day from baseline to follow-ups.
H4 will be analyzed with two bivariate comparisons. Two unpaired t-tests will be conducted to determine if the adherence rates differ by group after the 12- and 24-month follow-ups. Adherence will be measured in two ways: 1) number of modules completed on the program; and 2) total time spent on the program website.
To test the exploratory research question, bivariate comparisons will be conducted. Q1 will be analyzed with an unpaired t-test comparing group treatment ratings at each of the follow-up periods (3-, 6-, 12-, and 24-months).