Evaluating the efficacy of a community participatory intervention to prevent suicide in Thailand: a randomised controlled trial protocol

doi:10.1136/bmjopen-2022-066201

What this article is about

In brief

This is a study protocol, not a results paper, for a cluster randomised controlled trial testing a two-part community participatory intervention against usual care in two Chiangmai, Thailand subdistricts. It targets adults at high suicide risk, with suicidality symptoms as the primary outcome, and was designed...

For nursing students

Study summary

Thailand has the highest suicide mortality rate in Southeast Asia, holding steady at about 8.0 per 100,000 people in 2019. That is striking because Thailand already built a national, hospital-based suicide prevention system, rolled out from around 2010, that dramatically expanded access to depression care, from 5.1% of people with depression receiving care in 2009 up to 48.5% by 2016. Despite that success inside the health system, the national suicide mortality rate did not budge. The research team behind this trial concluded that something outside the hospital walls was missing: sustained involvement from the community itself. This protocol describes a cluster randomised controlled trial designed to test whether a community-driven, participatory intervention can do what the hospital-based system alone could not.

The trial takes place in two districts of Chiangmai Province, Mae Rim and Muang, both chosen because they have high local suicide rates. Because the intervention works at the level of whole communities rather than individual patients, the researchers could not randomise person by person. Instead they randomised at the subdistrict (cluster) level: one district was assigned to receive the community participatory intervention, and the other served as the control. From each of the two districts, researchers picked one larger and one smaller subdistrict, giving two intervention subdistricts and two control subdistricts overall.

The intervention itself has two connected parts that unfold over roughly two years. The first is a one-year capacity-building process built around five stages of workshops: an introductory workshop that orients local stakeholders to the project; a community participatory data-collection and planning workshop where local people help identify who is at risk and why; a series of key competency training workshops that build practical skills; workshops that put the group's own designed interventions into action; and finally a lessons-learnt workshop that captures what worked. All of this is carried out by a subdistrict core team of roughly 30 to 40 people, drawn from subdistrict health centre staff, municipality personnel, community health volunteers, family caregivers, and local community leaders. The second part is a full year of community-led action: counselling, psychosocial support, help with financial hardship, and education aimed at preventing self-harm, all designed and carried out by the community itself rather than imposed from outside.

Participants eligible for the study are adults 18 years or older who have at least one marker of elevated suicide risk: a past suicide attempt, a chronic mental illness, a chronic non-communicable disease, or a significant life crisis such as job loss, serious debt, or bereavement. People with active psychotic symptoms, those too unwell to take part, those planning to move away, and non-Thai speakers are excluded. Participants are recruited through subdistrict health centres.

Using a statistical power of 0.9, a significance level of 0.05, and a small-to-medium expected effect size, the researchers calculated they need 235 participants per study arm; after accounting for an expected 20% dropout, they are recruiting 294 per arm, for roughly 588 participants across the whole trial.

The main outcome the trial is measuring is suicidality symptoms, using an eight-question Thai-language screening tool with reported sensitivity of 0.96 and specificity of 0.91. Secondary outcomes include depression symptoms (using the PHQ-2 and PHQ-9), quality of life (EQ-5D-5L), stress levels, and how easily people can access health and community services. Because this is a protocol paper, it describes the planned methods rather than final results; findings have not yet been reported.

For nursing students, this study is a clear illustration of a community-based, upstream approach to suicide prevention that complements clinic-based care rather than replacing it. It also models how community health workers, not just clinicians, can be trained and organised to identify at-risk neighbours and respond with practical, locally relevant support. Students appraising this protocol should note its strengths, a clear cluster design, a pre-registered trial number, and ethics approval, alongside its real constraints: only two intervention and two control subdistricts, which limits statistical power and raises the possibility that people or ideas could "spill over" between neighbouring intervention and control communities.

Original publication

Source abstract and study details

Read the source abstract

Introduction The age-standardised suicide mortality rate in Thailand has been stable at a high level in recent years, highlighting the need for suicide prevention interventions. In Thailand, community involvement plays a key role in health promotion. The aim of this ongoing trial is to evaluate the efficacy of a community participatory intervention in two subdistricts in Thailand for reducing suicidality symptoms among individuals considered at high risk for suicide and compare the outcomes to two control subdistricts.Methods and analysis In this cluster (subdistrict) randomised controlled trial, we randomised two districts to either the community participatory intervention arm or the control arm. From each district, we selected one large and one small subdistricts. We estimated that we need 235 participants per study arm, who were recruited from subdistrict health centres. The primary outcome is suicidality symptoms. Secondary outcomes are depression symptoms, quality of life, stress level and health and community service accessibility.Ethics and dissemination This trial has been approved by the Research Ethics Committee, Faculty of Nursing, Chiangmai University (number 050/2022). All participants were required to provide informed consent. The findings of the study will be disseminated in peer-reviewed journals and via conferences.Trial registration number TCTR20220620003; the Thai Clinical Trials Registry.

Source type: Open access journal article

Reviewed findings

Main findings

This is a study protocol, so no outcome results are reported yet; it describes the planned design of an ongoing cluster randomised controlled trial.
Thailand's national hospital-based suicide surveillance and depression-care system (implemented from around 2010) raised depression care access from 5.1% (2009) to 48.5% (2016) but did not reduce the national suicide mortality rate, motivating this community-level trial.
The trial randomises two Chiangmai Province districts (Mae Rim and Muang) at the subdistrict level, with one district assigned to the community participatory intervention and the other to control.
The intervention combines a one-year, five-stage capacity-building process delivered by a 30-40 person subdistrict core team with a second year of community-led counselling, psychosocial support, economic assistance, and self-harm prevention activities.
The researchers calculated a required sample of 235 participants per arm (inflated to 294 per arm, roughly 588 total, to allow for 20% dropout), with suicidality symptoms measured by an 8-question Thai screening tool (sensitivity 0.96, specificity 0.91) as the primary outcome.

Using the findings

Practice considerations

Nurses working in community and public health settings can consider participatory, community-led models as a complement to clinical depression care, since hospital-based care alone did not reduce Thailand's suicide mortality rate.
Community health volunteers, caregivers, and local leaders can be trained as part of a structured, multi-stage capacity-building process to identify and support people at elevated suicide risk, extending the reach of formal mental health services.
Screening for suicide risk in community settings can target people with known risk markers, such as a past suicide attempt, chronic mental illness, chronic non-communicable disease, or a recent major life crisis, rather than the general population.
Brief, validated tools such as the 8-question suicidality screen and the PHQ-2/PHQ-9 can support routine identification of at-risk individuals in primary care and community health centres.
Because this is a protocol without reported outcomes, nurses should treat the intervention as promising in design but not yet evidence-based in effect; practice change should wait for the trial's published results.

For educators

Teaching and appraisal notes

This BMJ Open protocol paper, authored by Sornpaisarn, Rehm, Tamdee and colleagues from the Centre for Addiction and Mental Health (Toronto), Chiangmai University, and Thai community partners, describes an ongoing cluster randomised controlled trial testing a community participatory suicide-prevention intervention in Chiangmai Province, Thailand. It is a useful teaching case for research appraisal because it is transparent about design tradeoffs typical of community-level (as opposed to individual-level) trials.

The rationale is compelling for discussion: Thailand implemented a national hospital-based suicide surveillance and depression-care system from around 2010 that nearly tenfold-increased depression care access (from 5.1% in 2009 to 48.5% in 2016), yet national suicide mortality remained flat at roughly 8.0 per 100,000 (2019), the highest rate in the ASEAN (Southeast Asian) region. The investigators frame this as evidence that clinical-system improvements alone are insufficient without corresponding community-level engagement, a useful prompt for discussing the social determinants of suicide risk and the limits of hospital-centred prevention models.

Methodologically, the trial randomises at the subdistrict (cluster) level rather than the individual level, a common and necessary design choice when an intervention is inherently delivered to a whole community rather than to individual patients. Two districts (Mae Rim and Muang) selected for high suicide rates were each assigned wholesale to intervention or control, with one large and one small subdistrict sampled from each, yielding two intervention and two control clusters. This is a small number of clusters, and the authors explicitly flag the risk of contamination or "spillover effects" between neighbouring communities, along with the limited statistical power inherent to so few clusters, a good springboard for discussing the tradeoffs of cluster RCTs versus individually randomised designs.

The intervention combines a one-year, five-stage capacity-building process (introductory workshops, participatory data collection and planning, competency training, implementation of community-designed interventions, and a lessons-learnt phase) delivered by a 30-to-40-person subdistrict core team of health centre staff, municipal personnel, volunteers, caregivers, and community leaders, followed by a second year of community-led action including counselling, psychosocial and economic support, and self-harm prevention education. This bottom-up, capacity-building structure is worth contrasting with top-down, expert-delivered prevention programs when teaching intervention design.

Sample size was calculated with reasonable rigour (power 0.9, alpha 0.05, small-to-medium effect size of 0.3) yielding 235 participants needed per arm, inflated to 294 per arm (588 total) to allow for 20% attrition. Eligible participants are adults with documented risk markers, prior suicide attempt, chronic mental illness, chronic non-communicable disease, or major life crisis, recruited through subdistrict health centres; people with active psychosis, inability to participate, imminent relocation, or non-Thai language are excluded.

The primary outcome, suicidality symptoms via an 8-question Thai screening instrument (sensitivity 0.96, specificity 0.91), is well validated for local use; secondary outcomes (PHQ-2/PHQ-9 depression, EQ-5D-5L quality of life, a stress scale, and service accessibility) are internationally recognised and support cross-study comparison. Analysis of covariance is planned for the primary comparison, supplemented by thematic analysis of qualitative community data.

Ethically, the study received approval from the Research Ethics Committee, Faculty of Nursing, Chiangmai University (050/2022), is prospectively registered (TCTR20220620003), and requires written informed consent; the authors note patients and the public were not involved in designing the study itself, a limitation worth flagging given the intervention's participatory framing. As a protocol, no outcome data are yet reported. For seminar discussion, this paper works well alongside completed community-based suicide prevention trials to compare design choices and to discuss how nurses might translate a "capacity-building" model into Canadian community health settings.

Critical appraisal

Limitations

As a protocol paper, the trial has not yet reported outcome data, so efficacy claims cannot be made until results are published.
Only two intervention subdistricts and two control subdistricts are included, a small number of clusters that limits statistical power and the precision of the estimated intervention effect.
The small number of clusters raises the risk of spillover or contamination effects between neighbouring intervention and control communities, which the authors themselves acknowledge.

Classroom use

Discussion Questions

Why might a hospital-based depression care system succeed at increasing treatment access while failing to reduce national suicide mortality, and what does that suggest about the social determinants of suicide risk?
What are the advantages and disadvantages of randomising by subdistrict (cluster) rather than by individual participant in a community-level suicide prevention trial like this one?
How might having only two intervention and two control subdistricts affect the trial's statistical power and the confidence we can place in its eventual findings?
What is meant by 'spillover' or contamination between neighbouring communities in a cluster trial, and how could it bias the results of this particular study?
How does the five-stage capacity-building process described in this protocol (introduction, data collection/planning, competency training, implementation, lessons learnt) compare to how mental health programs are typically rolled out in your own practice setting?
What role do community health volunteers, caregivers, and local leaders play in this intervention, and how does that differ from a clinician-led suicide prevention program?

Source-based questions

Frequently asked questions

How does a cluster randomised controlled trial differ from a standard individually randomised trial?

In a cluster trial, whole groups (here, subdistricts) are randomly assigned to intervention or control, rather than individual participants, because the intervention is delivered at the community level rather than to single patients.