A Randomized Controlled Study of Collective Motivational Interviewing (CMI) for Adolescents With Internet Gaming Disorder
Phase: NA
Conditions: Internet Gaming Disorder
Sponsor: Hong Kong College of Technology

A Randomized Controlled Study of
Collective Motivational Interviewing
(CMI) for Adolescents with Internet
Gaming Disorder
Document Date: 1 March 2022
Uploaded: 24 March 2023
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Abstract
Internet gaming disorder (IGD) is a widespread public health problem. Hong Kong is no
exception. In alignment with the global trend of the increasing concern on IGD among young
people, especially during the COVID-19 pandemic, the situation becomes worsened. Because
of the social distancing measures, students stay home for virtual classes, and screen time
increases. They are prone to engage in numerous digital activities, such as gaming, social
media, binge-watching, and so on.
Excessive online gaming by adolescents could lead to getting too little sleep, eating
improperly, failing to maintain proper personal hygiene, and withdrawing from social
interactions, which also detriment interpersonal development. With the atmosphere of
“Academic Performance First” in Hong Kong, most parents stress on academic
accomplishments of their children, leading to strained relationships when their child’s gaming
behaviour threatens educational efforts.
Our project collaborators, including Caritas, HKCYS, HKPA and the largest
counselling teacher’s association, also alert the IGD problems among adolescents in Hong
Kong. They look for a low-threshold, brief and effective intervention to deal with the
concern. However, in some existing interventions for IGD, such as cognitive behaviour
therapy and multidimensional family therapy, the inadequate research method caused no
strong conclusions on its efficacy. Motivational Interviewing (MI) is an evidence-based
counselling approach with over three thousand randomized controlled trials across
populations, disciplines, settings, and cultures. MI was originally developed for treating
alcohol problems and further applied to address lifestyle problems in healthcare settings, but
it was never examined for IGD. Furthermore, in literature, the effectiveness of MI for
adolescents varied. Both the service and research gaps have opened a fruitful opportunity for
this project.
Collective Motivational Interviewing (CMI) is a locally innovated change technology to
mobilise a client’s motivation to change with the support of concerned significant others
(CSOs). CMI roots in the forty decades of MI evidence in addictive treatment,
groundbreaking to engaging CSOs into the motivational process to cultivating positive and
productive dialogues among the involved parties. The proposed study rides on the
preliminary result of CMI in drug addiction in terms of reducing drug use, enhancing
motivation, and strengthening social support, which has confirmed the feasibility of CMI in
working with addictive behaviours.
Our international research team will conduct a parallel two-armed randomized
controlled trial to test the efficacy of CMI in improving IGD among adolescents with IGD in
Hong Kong (N = 172 pairs of adolescents and their CSOs). The research participants will be
randomly assigned to the intervention group (CMI intervention plus IGD education materials)
and control group (IGD education materials only). The primary outcome of the efficacy of
the intervention will be indicated by the severity of IGD symptoms, together with secondary
outcomes of motivation to change maladaptive gaming behaviour, craving for gaming, and
social support from CSOs; such indicators will be measured at baseline, post-intervention,
3-month follow-up, and 6-month follow-up. In addition, fidelity control will be monitored.
The proposed project responds to the vision of RGC 「活研活用」that transfers research
knowledge and skills into promoting a better quality of life for individuals, communities and
society as a whole. CMI intends to provide a promising solution to this alarming public health
topic. The present study will also contribute to the local Chinese community with a practical
intervention approach for counsellors, social workers, and service providers to improve the
quality of life among adolescents with IGD and their CSOs. Still, it undoubtedly facilitates
international scholarly discussions in its feasibility, applicability and replicability.
RESEARCH DETAILS
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1.
Project Objectives
The primary objective of the proposed randomized controlled trial (RCT) is to investigate the
relative efficacy of collective motivational interviewing (CMI) plus provision of education
information in the intervention group versus that of provision of education information alone
in the control group in reducing symptoms of Internet gaming disorder (IGD) among
adolescents at risk of IGD (i.e., probable IGD cases) aged 10-16 years in Hong Kong.
Secondary objective is to (a) enhance motivation for change maladaptive gaming behaviours,
(b) reduce cravings for gaming, and (c) enhance support obtained from the concerned
significant others (CSO). It is hypothesized that better primary and secondary outcomes
would be obtained in the intervention group than in the control group.
2.
Pathways to Impact Statement
There are several contributions and impacts of this study:
1. Academic impact:
The development of psychotherapy was driven mainly by research conducted in Western
countries. Health professionals in Hong Kong always learn and apply the counselling
approach developed in the West. Motivational Interviewing (MI) is a powerful
evidence-based and hand-on counselling tool that helps people to make a change. It is
very commonly used among health professionals in areas such as addiction. Yet, the
latest MI literature often discusses about two areas that may need improvement. First, it
is well known that influences of significant others (e.g., family members) are significant
factors of behavioural change. In both real-life counselling practices, loved ones
frequently place excessive blame on the client, which makes conjoint interviews
unhelpful and even damaging their relationship. The first important challenge is how to
apply MI- counselling style with the significant others, so as to enhance their readiness
and sharpen their language use in a supportive way, i.e., how to create a collaborative
change partnership between the client and his/her CSO. The second challenge and
novelty of the proposed study is that, to the best of our knowledge, MI has been tested in
populations of substance addiction (e.g., alcohol use, smoking, and substance use), but
NOT in the context of reducing Internet gaming disorder (IGD) with a robust method
(e.g., RCT).
2. Collective motivational interviewing (CMI) is a novel intervention method developed by
the principal applicant. It is a culturally feasible counselling approach that can potentially
reduce addictive problems. In this present study, CMI extends the application of MI to a
new social nexus paradigm by incorporating both the clients and their CSO in the
motivational interviewing process, which is distinctive from that of the original MI
process, which involves one-on-one counselling. It is also different from family therapy
which joins family members together without considering how to get both parties ready
to make a collaborative change. The present RCT investigates the efficacy of CMI in
reducing IGD. A tailored fidelity control instrument will be used to monitor the quality
of CMI intervention. To create global influences, Dr. Mark Griffiths (Co-I), who is the
director of the international gaming research unit, will create international academic
discussions in meetings or webinars on applications of CMI for reducing IGD.
3. Practice/clinical impact:
The concern over IGD is increasing in different societies. It has detrimental effects on the
development of adolescents in terms of physical, psychological, and social aspects. Many
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parents solicit assistance from social services. However, IGD tailored services are
unavailable in Hong Kong. It might be attributed to a lack of effective intervention
approaches to deal with IGD. Most mainstream service provision in Hong Kong remains
focused on public education. Social service providers and health professionals are
looking for empirically validated, hands-on skills, brief, and low-threshold counselling
approaches to help adolescents with IGD and their families. There is hence a pressing
need to investigate the efficacy of CMI as a robust methodology to fill out the service
gap.
4. Professional impact:
The project will boost the capacity building of the frontline social workers, counsellors,
and health professionals by equipping them with advanced counselling skills on CMI.
The development and application of CMI will make a long-lasting impact on
professionals of social services, health, and education to deal with adolescent IGD
problems. In addition, the service providers may also apply CMI to the population of the
hidden drug misusers and/or non-engaged youths, motivate them to change, and develop
better lifestyles with the support of CSOs.
5. Educational impact:
The CMI intervention protocol for IGD and the fidelity instruments will be published for
sharing with other local and international researchers who may be interested in this
counselling approach. In addition, the present study would modify a CMI protocol – IGD
version from the version for drug use problems which is a valuable teaching material for
disseminating the good practice approach to address IGD among adolescents.
The CMI training workshops would provide an in-depth understanding of the application
of CMI in working with adolescents with IGD.
Social media dissemination: Apart from the traditional written work, Dr. Tse Ka-wo will
also dissimilate the application of CMI for IGD via the YouTube Channel. Social
work/counselling/psychology students and other interested scholars who would like to
understand how CMI is applied to IGD/ the findings of the present study/ CMI
demonstration can visit the YouTube Channel. The above education plan would foster the
broader use of CMI in clinical settings.
3.
Research Project Statement
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Introduction
Internet gaming disorder (IGD) is a widespread public health problem. It has been formally
recognized as a diagnosable mental health condition in the appendix of the fifth edition of the
Diagnostic and Statistical Manual of Mental Disorders (DSM-5)(American Psychiatric
Association, 2013) and a mental health disease in the International Classification of Diseases
11th version (ICD-11) (World Health Organization, 2018). It is characterized by persistent
gaming behaviour, impaired control over gaming, and functional impairment, usually for a
period not less than 12 months (Carlisle, 2021). People with IGD prioritize gaming over other
activities, resulting in missed life opportunities for other activities and interference with
regular self-care (i.e., sleeping, eating and drinking, personal hygiene), fewer face-to-face
interactions with others and detrimental social relationships (e.g., family and friends), and
important obligations, such as education and work, care of children (Carlisle, 2021;
Humphreys, 2019; Kim et al., 2022; Peter et al., 2020).
Prevalence of IGD
The prevalence of IGD estimates ranged from 2% to15% internationally. The varied findings
may be partly due to variations in definitions of IGD, assessment instruments, and sampling
(Gentile et al., 2013). A systematic review and meta-analysis reported that the pooled global
prevalence of gaming disorder was 3.05% (Stevens et al., 2021). The time between ages 12
and 18 is generally the most vulnerable period for developing addictive disorders, including
IGD (Gentile et al., 2017). The prevalence of IGD among adolescents was 4.6%, according to
a meta-analysis, male adolescents (6.8%) tended to have a higher prevalence of IGD than
female adolescents (1.3%) (Fam, 2018). The prevalence of adolescents with IGD was 14.6%
in the U.K. (Lopez-Fernandez et al., 2014), 1.16% in Germany (Rehbein et al., 2015), 5.9%
in Korea (Yu & Cho, 2016), and 5.5% in the Netherlands (Lemmens et al., 2015); 17.0% of
the Chinese adolescent game players have had IGD according to the diagnostic criteria (Liao
et al., 2020). The prevalence of IGD among adolescents in Hong Kong was higher than that
of the global average level. The latest student survey in Hong Kong, during the COVID-19,
about 83% of students participated in gaming activities, the prevalence of excessive and
pathological game addiction was 20.9% and 5.3%, respectively (Zhu et al., 2021). It is hence
warranted to reduce IGD symptoms among those showing such symptoms and are at high
risk of IGD.
Impact of IGD on adolescents
IGD could cause multidimensional negative impacts on adolescents. A review of longitudinal
studies reported that adolescent IGD was predictive of increased physical problems (e.g.,
increased physical aggression), mental health problems (e.g., depression and anxiety),
psychosocial problems (e.g., social phobia and poor parent-child relationship), and worsened
academic achievements (Mihara & Higuchi, 2017).
Family interaction and IGD
Evidence implicates that familial influences contribute to both the risk and sustainable factors
of adolescent IGD problems. Adolescents with IGD often reported more family conflicts and
worse family relationships (Bonnaire & Phan, 2017) and poor interpersonal relationships and
conflicts (Wartberg et al., 2017) than non-IGD adolescents. In addition, several familial
influences, such as the parent-child relationship, supervision of gaming, parent
socioeconomic status, and family composition, may affect the chance an adolescent turns into
a problematic gamer (Schneider et al., 2017). Some interventions related to IGD also
involved family members. Family hence plays an important role in development and
interventions regarding IGD.
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Intervention approaches for IGD
Researchers and health care workers have pointed out that there is a strong but unmet demand
for interventions that can effectively reduce IGD symptoms (Zajac et al., 2020). The number
of interventions backed up by randomized clinical trials (RCTs) is small and inadequate
(Zajac et al., 2020). Theory-based RCTs are strongly warranted, and this study is an
innovative attempt. A systematic review and meta-analysis has shown that cognitive
behavioural therapy (CBT) effectively reduces IGD and depressive symptoms and may bring
short-term benefits (Stevens et al., 2019). Group CBT has also reduced IGD symptoms (Han
et al., 2020). As discussed, adolescent IGD may not always be solely attributable to
intrapersonal factors which CBT targeted, but also to familial and parental factors (Nielsen et
al., 2020). In addition, Bonnaire et al. (2019) recommends that it is crucial to involve family
members when treating adolescents with IGD. Interventions for adolescents may be more
effective when taking into consideration the family context, rather than emphasizing only
individual-based treatment (Schneider et al., 2017). Social network incorporated interventions
(e.g., family members) require more empirical attention given their promising findings (Liu
et al., 2015). Multidimensional family therapy (MDFT) was useful in treating adolescent
IGD, which focused on improving family relationships to contribute to the treatment
outcome. Yet, MDFT is a relative intensive approach and requires more sessions, and the
small sample size of the MDFT studies limits the generalizability (Nielsen et al., 2021).
Alternatively, the proposed Collective Motivational Interviewing (CMI) is a brief,
low-threshold, concerned significant others-involved counselling tool to facilitate productive
conversation among involved parties (Tse et al., 2022).
A novel intervention grounding on evidence of Motivational Interviewing (MI)
accumulated in four decades
Motivational Interviewing (MI) is an evidence-based psycholinguistic counselling approach.
The essence of MI is the combination of a client-centred approach and goal-oriented
strategies. It helps people resolve ambivalence about changing with the spirit of partnership,
acceptance, evocation and compassion. Counsellors emphasize exploring the client’s own
reasons for change by developing the discrepancy between the status and the desired goal.
Client-centred counselling skills consist of open-ended questions, reflection, summary and
affirmation, formulating a guiding communication style to facilitate clients’ self-exploration
on their own reasons for change. Four-process model includes engaging process, focusing
process, evoking process and planning process, leading a more systematic and structured
motivational process (Miller & Rollnick, 2013).
MI can be implemented by trained social workers, teachers and counsellors and even research
assistants and is thus a scalable method. Initially, MI was nurtured in working with alcohol
problems, extensively examined in drug addiction. Subsequently, it has been broadly applied
in healthcare settings to motivate patients to make behavioural changes. Its effectiveness has
been examined more than 3000 RCTs across disciplines, populations, settings, and cultures
(Hallgren et al., 2018; Miller & Moyers, 2021). It has been effective in changing addictive
behaviours such as substance use, smoking, alcohol (Miller et al., 2003). The principal
applicant and Li et al. (2016) jointly published a systematic review and meta-analysis that
demonstrated the efficacy of MI for adolescents with illicit drug use. Yet, MI has seldom
been applied to deal with adolescent IGD. Furthermore, the individual-based MI did not take
into account the influence of significant others (e.g., family members), as most IGD cases
begin at adolescence and prompting family involvement is a critical part of the intervention
process.
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Concerned significant others (CSOs) is a major source influencing one’s motivation. For
instance, the Theory of Planned Behavior suggests that support given by the significant others
(subjective norm) is a strong determinant of health-related behaviour (Mak & Davis, 2014).
The family-based approach has been gaining traction as a preferred intervention for
adolescent IGD problems. Collective Motivational Interviewing (CMI) is thus crucial and a
potential breakthrough that integrates MI with CSOs’ influences. Previous research has never
examined the efficacy of MI sessions involving both the client and his/her CSOs for IGD.
The involvement of CSOs in MI is potentially important. For instance, family members might
place too much blame on the client, often causing counterproductive result. The conjoint MI
sessions proposed in this study aim at creating understanding and supportive interactions that
boost the adolescents’ motivation to make changes regarding Internet gaming. Readiness of
client and CSO is the key to fostering joint change partnership.
Details about Collective Motivational Interviewing (CMI)
CMI is a newly developed motivational approach, which was developed to firstly to tackle
substance use problems. It is derived from the aforementioned evidence-based
psycholinguistic counselling method of MI. It involves MI sessions targeting both the client
and his/her CSOs. The principal investigator is the developer of this method. CMI retains the
brief, client-centred and goal-oriented features of MI but expands the application of MI to the
social nexus paradigm (i.e., CSO). It only requires four short sessions. Individual sessions are
held for the client and CSOs, respectively, elicit the client’s motivation to chang, and
furthermore, cultivate CSO’s motivation to support the client to change, followed by two
conjoint sessions that would facilitate a joint change partnership toward a clear, common,
achievable goal under an atmosphere of non-judgemental climate, with non-threatening trust
and mutual support (Tse et al., 2022). A pilot study has examined the feasibility of CMI
among twenty pairs of persons with drug use problems and one of their respective CSO. The
preliminary findings showed that CMI was able to achieve reduction in drug use (z = -2.02, p
< .05, r = -.319), enhancement of motivation to change [F(3, 17) = 7.78, p < .01, η² = .579),
and strengthening social support (z = -2.14, p < .05, r = -.338 ) at three-month follow-up (Tse,
2021). This study further applies CMI to adolescents with IGD and their CSOs.
Research and service gaps
Feasible low-intensity evidence-based interventions for IGD are not available in the field. To
our knowledge, no MI intervention has been tested in treating IGD. There is a strong and
unmet need to expand MI to motivate the adolescents to change and their CSOs to support
them. Most clinical trials on IGD reduction examined CBT and Family Therapy which were
relatively structured and intensive. Such interventions require trained clinical psychologists
which are expensive to access and in short supply in general. Furthermore, motivation is a
prerequisite to participate in such interventions, which is often lacking. CMI is a brief,
motivational-focused, and CSO-involved motivational tool. As a stand-alone intervention
approach, CMI can provide a safe platform for adolescents with IGD and their CSOs to create
constructive dialogues, which are much needed but hard to happen. CMI would also facilitate
mutual understanding and support to reach a common goal. As a prelude tool, CMI can also
help to get ready both parties to participate in other intensive treatment.
Methodological robustness is important. Notwithstanding the latest systematic review
showing the recent increase in the publication of interventions for IGD, methodological
inadequacies (e.g., a lack of control groups) make it tough to draw definitive conclusions
about the effectiveness of IGD interventions (Zajac et al., 2020). RCTs with follow-up
assessments is a robust way to examine the efficacy of IGD intervention (King & Delfabbro,
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2019; Zajac et al., 2020). The proposed RCT fills out the aforementioned gaps. As MI can be
performed by trained non-professionals (e.g., peer counsellors), it increases scalability and
potential applications in the future.
Research questions
The present study examines the efficacy of CMI in reducing adolescent IGD symptoms and
enhancing social support given by CSOs among adolescents with high risk of IGD (probable
IGD cases screened positive by validated tools). It is hypothesized that the intervention group
(with CMI plus IGD education materials for both the clients and his/her selected CSO) would
show more improvements in reduction in the severity of IGD, motivation to change
maladaptive gaming behaviour, craving on gaming, and social support obtained from CSOs
than to the control group (only educational materials for both the client and the CSOs) from
the baseline (T0) to posttest (T1), 3-month follow-up (T2) and 6-month follow-up (T3). The
research question is whether CMI would result in better intervention outcomes than the
control group.
Study design
This study adopts a randomized controlled efficacy study with an open-label parallel-group
design (see the flowchart on p.30). The trial will be registered by the WHO’s International
Clinical Trials Registry Platform once the project is approved. Research participants will be
recruited from the primary and secondary schools, and the youth social services. After
completing the screening process, research participants who are confirmed to fit the inclusion
criteria will be randomly assigned to the intervention group with CMI intervention plus IGD
education materials to both adolescents with IGD and their CSO or the control group with
IGD education materials alone. The present study sets four-time points to track change the
between-group difference of the primary and secondary outcomes from the baseline (T0) to
post-intervention (T1), 3-month follow-up (T2) and 6-month follow-up (T3).
Target research participants
Inclusion Criteria include: (1) adolescents aged between 10-16; (2) probable IGD condition
screened by the Internet Gaming Disorder Scale-Short-Form (IGDS9-SF) reaching the cut-off
value at 32, those at high risk of having IGD but no IGD cases with clinical diagnosis,
although the symptoms measured by IGDS9-SF are equivalent to DSM-5 IGD criteria); (3)
Hong Kong ID card holder; (4) Chinese speaking; (5) student identity; (6) possessing an
electronic mobile device or computer, and (7) willingness to participate in the
intervention/control group and complete four surveys (baseline, post-intervention, 3-month
follow-up, and 6-month follow-up); (8) can nominate a CSO (e.g., parents) [client’s
autonomy is a critical factor to facilitate motivation posited by the self-determination theory
(Ryan & Deci, 2020) ], and (9) to obtain informed consent and parental consent. The
justification for the age group: (a) according to the World Health Organization, adolescents
are those aged 10 to 19, (b) previous student survey reported that the mean age of students
with excessive and pathological gaming is 12 years old (Zhu et al., 2021), and (c) Hong Kong
adolescents aged 10-16 had higher prevalence of IGD and greater needs for intervention
based on PI’s and collaborators’ practice experiences. Exclusion Criteria: Participants
self-reporting having psychiatric problems such as psychosis, significant cognitive
impairment and/or receiving active and structured psychotherapy about IGD elsewhere will
be excluded (Nielsen et al., 2021). Inclusion criteria for CSO included those (1) aged greater
than 18 years (2) having close relationship with the adolescent with probable IGD (as rated
by participants being generally supportive of the participants) and (3) being willing to
participate in the present study and provide informed consent. Exclusion Criteria for CSO
include those self-reporting (1) having psychosis, aggressive or suicidal behaviour and (2)
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having life-threatening medical conditions.
Recruitment
The target participants are between the ages of 10 and 16 years old; Our project develops a
strong local alliance with three leading children and youth services in Hong Kong, including
Caritas Hong Kong, Hong Kong Children & Youth Association, and Hong Kong Playground
Association. On top of it, the largest counselling teacher’s association covers the largest
network of primary schools and secondary schools have agreed to facilitate the recruitment
process. For recruitment via the children & youth service (Pathway A), Introduction package
will be delivered to the collaborative agencies, including: (a) briefing sessions (either zoom
or in-person, dependent on the feasibility); (b) QR codes with access to information about the
project; (c) training for the fieldworkers (collaborators’ staff, including social workers/
counsellors/ psychologists), to identify potential participants and teach them how to use the
screening tool and the inclusion and exclusion criteria through a standardized pre-recorded
video. For recruitment via School counselling services of the Primary and Secondary Schools
(Pathway B), the project officer or PI will send invitation letters to all school social
work/counselling services through the network of the Hong Kong Association for School
Discipline and Counseling Teachers that covers most primary and secondary schools in Hong
Kong. Research team will conduct three open briefing sessions (either zoom or in-person,
dependent on the feasibility). Interested schools will be invited to join the briefing sessions.
The introduction package, the same as the one in Pathway A, will be sent to social workers of
such schools. Afterwards, the trained fieldworkers (agency’s staff) will screen prospective
participants from both Pathway A and Pathway B (including both participants and the CSOs)
for their eligibility, obtain informed consent from i) the participants and their parents and ii)
the CSOs, and refer the participants to the project officer (i.e. the social worker recruited for
managing this study).
Baseline screening and randomization
With written informed consent obtained from both target research participants and their
CSOs, the baseline survey will be conducted over the phone for about 15 minutes to obtain
data about potential confounders (e.g., socio-demographics) and key variables (e.g.,
motivation to change and cravings on gaming). As the present study will adopt a two-armed
RCT to examine the efficacy of CMI on improving IGD among adolescents with IGD. The
research participants will be randomly assigned to either the intervention group (four-session
CMI intervention plus IGD educational materials) or the control group (IGD education
materials alone). Block randomization will be executed, of which the block size is 4.
Computer-generated randomization allocation codes will be produced and sealed in opaque
envelopes by a research associate with no involvement in recruitment. One envelope will be
drawn and opened by the project officer.
Control group
The control group with IGD education materials alone
After completing the baseline screening, survey and randomization, the participants in the
control group will receive educational materials regarding topics including: (1) what IGD is
and its consequences, (2) how to communicate with parents about the gaming time, and (3)
how to develop a healthy lifestyle, etc. The research team will develop the IGD education
materials and provide them through the electronic mean, say WhatsApp.
Intervention group
The intervention group with CMI intervention plus IGD education materials
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Eligible participants will be given the same IGD education materials that are given to the
control group by e-channel. They will further participate in the four-session CMI
intervention. Trained CMI practitioners will follow the CMI intervention protocol-IGD,
which will be modified from the CMI intervention protocol for families with drug use
problems to conduct the counselling session. In the first session (60 mins), adolescents with
IGD will be implemented a standard MI session to elicit and strengthen the clients’
motivation to change. In the second session (60 mins), a nominated CSO of the client will
participate in a standard MI session to elicit their motivation to help the client toward change
and prepare positive attitudes of CSO for the conjoint session. Afterwards, the third (75 mins)
and fourth sessions (75 mins) will be conjoint sessions. The CMI practitioners will create a
safe platform for both parties to share their perspectives with openness and trustfulness, in
turn, to reach an agreed goal (e.g., develop a change plan on internet gaming behaviours). All
interview sessions will be conducted in a counselling/meeting room at the schools or the
service unit of the collaborators.
The follow-up survey
The present sets four time points to track change the outcome indicators from the baseline
(T0) to posttest (T1), 3-month follow-up (T2) and 6-month follow-up (T3). The telephone
follow-up survey will be conducted by a research associate/project officer independent of the
intervention.
Measurements (Appendix 4)
Assessments and measures
Assessments will be conducted at the baseline (T0) to posttest (T1), 3-month follow-up (T2)
and 6-month follow-up (T3). Personal information will be gathered at baseline and 6-month
follow-up, covering socio-demographics, risk behaviors, parenting style, school and work
performances, peer relationship/support, and recreational activities. Apart from the
questionnaire for the primary client, a questionnaire for parents is also included to track the
changes in the parent’s perception of the client’s gaming severity, parental stress, parents’
motivation to help, and feedback on the counseling process, in order to understand the impact
of family engagement in the treatment process. The key outcome measures used in the
present study will be described below:
Primary outcome - Severity of IGD
The nine-item Internet Gaming Disorder Scale-Short-Form (IGDS9-SF) will be used to detect
the change in the severity of IGD. It is the first brief standardized psychometric tool of IGD
based on the nine DSM-5 IGD criteria. This instrument has been translated into 15 languages
and is widely used in research and clinical settings. In addition, a validated Chinese version
with satisfactory psychometric properties is available (Qin et al., 2020). The items were rated
by using 5-point Likert scales (1 = Never to 5 = Very often). The commonly-used cut-off
value of 32 will be used to differentiate between IGD and non-IGD (Qin et al., 2020).
Secondary outcomes
Motivation to change maladaptive gaming behaviour
Contemplation Ladder for Internet Gaming (CL-LG), which is derived from the
Contemplation Ladder measure the motivation to quit smoking (Biener & Abrams, 1991),
will be employed. Contemplation Ladder for drug use problems is commonly used in clinical
settings and research in Hong Kong (Siu et al., 2018). The instrument measures the
motivation to abstain from maladaptive gaming behaviours based on a single brief option of
11 rungs and five types of statements. The instrument is rated on a scale from 0 to 10, with
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each point representing a specific statement showing a corresponding stage of change. The
ladder has been used in smoking cessation studies, which displayed strong reliability and
validity with strong intercorrelations (Pearson’s r = .82 - .98) (Rustin & Tate, 1993).
Craving for Internet Gaming
Craving for Internet Gaming Scale (CIGS) will be used. This CIGS is a unidimensional,
self-report measure that assesses respondents’ intensity, frequency, duration of their craving,
and capability to resist acting on their craving for a particular period of time. It comprises
five-item, scoring from 0 to 6 for each item. Respondents with higher scores tend to have
higher levels of gaming craving (Cronbach’s alpha was .88-.91) (Savci & Griffiths, 2019).
Social support from CSO
The 4-item significant other subscale of the Multidimensional Scale of Perceived Social
Support (MSPSS) will be used. It is a self-reporting instrument designed for assessing the
level of perceived social support from significant others. The items are scored on a 7-point
Likert scale ranging from 1 (very strongly disagree) to 7 (very strongly agree). The
Cantonese version has demonstrated high internal consistency coefficient with a Cronbach’s
alpha of .89 (Chou, 2000).
Pilot study
Developing and revising the CMI Protocol for the IGD version
CMI protocol for families with substance abuse problems was developed in 2016. The
protocol was examined the feasibility throughout the doctoral study of the PI between
2017-2019. Based on the previous CMI protocol, the research team will modify the treatment
manual and convert it into IGD-specific content.
Pilot study
A pilot study will apply CMI to three pairs of adolescents with IGD and their CSOs. Four
essential aspects will be tested, including process, resources, management and scientific
(Thabane et al., 2010). It serves four aims to: (1) examine the flexibility of the revised CMI
protocol, (2) check the readiness of pretest and posttest questionnaires, (3) the procedures for
randomization, data collection and administrative tasks to make sure its smooth run. The
project officer will interview both clients and CSOs regarding their subject experiences
participating in the CMI intervention. The findings of the pilot study will provide evidence to
modify the intervention protocol if needed for the main study.
Sample size estimation
We used G* Power software to calculate the sample size for the main study. (Faul et al.,
2007). Considering that the between-group difference of IGD symptoms (the primary
outcome) will be estimated with a medium effect size of .5, together with power of 80% and
significance level of .05, a total sample size of 128 is required, which implies that 64 eligible
paired participants (i.e., one participant paired with one CSO) are required for the
intervention and control group, respectively. Referring to the dropout rate of 24.6% in CBT
and MI for internet addiction (Thorens et al., 2014), this study allows the attrition rate of up
to 25% at 6-month follow-up; the final sample size will be N = 172 paired participants (86 for
intervention and control group each).
Statistical analysis plan
Baseline background data of the intervention and control groups will be compared by using
t-test or X2test. Comparisons between the dropouts and non-dropouts will be analyzed. The
11

between-group (intervention versus control groups) differences in the primary and secondary
outcomes will be compared by using logistic regression adjusting for baseline variables
showing significant differences (i.e., potential confounders) as well as baseline values of such
outcome variables. Intention-to-treat analysis will be used to examine between-group
differences in the outcomes across time at baseline (T0) to posttest (T1), 3-month follow-up
(T2) and 6-month follow-up (T3). Absolute and relative risk differences, number needed to
treat (NNT), and respective 95% confidence intervals (CIs) will be reported. Multivariate
analysis (e.g., Generalized Estimating Equation (GEE) for repeated measures) will also be
applied to look at the between-group differences in the overall changes of the outcomes along
time (e.g., time × group interactions). One of the investigators (JTFL) is experienced in
evaluating RCT studies.
Training and supervision
Professional training in Collective Motivational Interviewing for frontline workers
Collaborative parties are expected to nominate social workers/counsellors/counselling
teachers to join a series of CMI training workshops (40 hours), which are led by the first and
the only MINT certified MI trainer & a rater for the MI trainer certification scheme (PI-KW)
in Hong Kong and also one of the founding researchers of CMI. The PI has solid clinical
practice experience delivering MI-style practice, providing training and supervision. All
prospective CMI practitioners are required to pass the competency assessment of CMI before
providing the intervention in a real-life setting. It is expected that 5-8 CMI trainees will pass
the competency assessment and conduct CMI sessions. Each trainee will take up 5 cases, then
the maximum cases shared by CMI trainees will be 40 cases. The rest of the cases will be
delivered by the project officer. The PI will provide on-job training to ensure the project
officer will pass the CMI competence assessment.
Fidelity control
All trained CMI practitioners will follow the CMI intervention protocol for IGD to deliver the
CMI intervention. The CMI intervention protocol – IGD will be modified from the original
CMI protocol for people with drug use problems (Tse & Tse, 2016). On-going supervision
will be held for the CMI practitioners to avoid therapist drift and offer support to resolve
some difficulties in the CMI delivery. With the consent of research participants, all sessions
of interventions will be audio-recorded to monitor and ensure the quality of CMI
intervention. In addition, 20-min segments from 15% of CMI sessions will be randomly
selected to go through the coding process for fidelity control by an expert third party who
have been trained using the Collective Motivational Interviewing Treatment Integrity coding
manual (cMITI) (Feldstein Ewing et al., 2021; Tse & Tse, 2020). cMITI was derived from the
motivational interviewing treatment integrity coding system (Moyers et al., 2016). Two
coders will analyse the same segments and make an agreement on the coding result.
Inter-rater reliability will be reported.
Ethical considerations
Ethical approval for the present study involving human participants will be obtained from the
Research Ethics Review Panel, Research Coordination and Development Committee at
CTIHE. In the present study, participants will be referred voluntarily from the schools and
youth social service providers. The project officer will thoroughly explain the study goal,
procedures, and potential benefits and risks to each participant. The project will obtain
written informed consent from the clients (and their parents) and CSOs.
Contingency plan for the COVID-19 and other outbreaks of public health issues
12

When the social distancing measures are stringent because of the COVID-19 outbreak and
another public health emergence in Hong Kong; face-to-face CMI intervention may be
impossible. Then two alternatives will be considered. First, the CMI intervention will be
moved to the Zoom/Online video conference platform. Second, the project may be postponed
if approved by the RGC.
13

Flow chart of the Randomized Controlled Trial (RCT)
14

Project timetable
Year 1 - 2023
Year 2 - 2024
Year 3 - 2025
Month
Tasks
Season
1-3
4-6
7-9
10-12
1-3
4-6
7-9
10-12
1-3
4-6
7-9
10-12
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
PLANNING & DESIGN
CMI intervention protocol-IGD
Ethical approval
Invite schools and confirm the
participating schools
Liaise collaborators and schedule the
briefing sessions
Recruitment of project officer &
student helper
Develop introduction package for the
project
Develop IGD education materials for
control group
Prepare pretest and posttest battery
Train project officer
CAPACITY BUILDING
Promote CMI workshop
Conduct CMI workshop
CMI competency assessment
INTERVENTION PHASE
Piloting
CMI intervention
DATA MANAGEMENT
Baseline Assessment
Follow-up survey
Data analysis
FIDELITY CONTROL
On-going supervision
Coding process
DISSEMINATION
YouTube Videos
Journal articles
Project evaluation and writing up
reports
15

4.
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