Resilience-Building Intervention for Older Informal Caregivers

• Multicomponent Resilience-building Program (Behavioral): Participants in the intervention group will receive the THRIVE program, an 8-week multicomponent resilience-building intervention developed based on prior participant need assessment, empirical evidence on resilience theory and caregiver resilience interventions, and stakeholder input. The intervention aims to strengthen psychological resilience among older informal caregivers. The format will be alternating in-person and online sessions conducted weekly over 8 weeks. In-person sessions will be held at participating Active Ageing Centres, while online sessions will be conducted through Telegram group video calls. Each 1.5-hour session will include: 1) psychoeducation; 2) peer support group sharing; and 3) an AI chatbot trained using local official resources. Sessions will be delivered by the same trained facilitator using a standardized intervention protocol. An independent observer will complete a fidelity checklist during each session to assess adherence to the protocol.
• AI Chatbot and Telephone Follow-up Group (Behavioral): Participants will receive access to the same AI chatbot trained using information from local official health education and caregiving support resources. Participants will also receive weekly telephone follow-up calls from the research team over the 8-week study period. The telephone follow-ups aim to: 1) encourage use of the AI chatbot; 2) address any technical difficulties encountered during chatbot use; and 3) gather participants' feedback and experiences using a standardized telephone follow-up guide. All telephone calls will be audio-recorded and reviewed by the research team for fidelity monitoring to ensure consistency of delivery across participants.

Primary outcomes

• Recruitment Rate [From date of randomization until the date of first session of the intervention, assessed up to 2 months.]: Proportion of eligible participants who provide informed consent and complete baseline assessment.
• Participant Retention Rate [Assessed from the first session of the intervention to Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: Proportion of enrolled participants who complete the post-intervention (T1) and 3-month follow-up (T2) assessments.
• Intervention Adherence [Throughout the 8-week intervention period.]: Participant adherence to intervention activities, including attendance at in-person and online sessions, completion of telephone follow-up calls, and engagement metrics with the AI chatbot.
• Intervention Acceptability [Assessed at Post-intervention (T1): within 2 weeks after completion of the 8-week intervention.]: Participant acceptability of the intervention will be assessed using a post-intervention satisfaction survey and qualitative feedback collected through focus group discussions to explore participants' experiences, perceived usefulness of the intervention, barriers and facilitators to participation, and recommendations
• AI Chatbot Usability [Assessed at Post-intervention (T1): within 2 weeks after completion of the 8-week intervention.]: Usability of the AI chatbot will be assessed using the Simplified System Usability Scale (SUS). The SUS consists of 10 items rated on a 5-point Likert scale. Responses are converted to produce a total score ranging from 0 to 100, with higher scores indicating better perceived usability.

Secondary outcomes

• Psychological Resilience [Assessed across 3 time-points: Baseline (T0): within 2 weeks before the first intervention session. Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: Assessed using the Connor-Davidson Resilience Scale (CD-RISC-25) to explore preliminary trends in intervention effects on resilience. The CD-RISC-25 consists of 25 items, with total scores ranging from 0 to 100. Higher scores indicate greater psychological resilience.
• Intrinsic Capacity [Assessed across 3 time-points: Baseline (T0): within 2 weeks before the first intervention session. Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: Intrinsic capacity will be assessed using the World Health Organization (WHO) Integrated Care for Older People (ICOPE) screening tool to explore preliminary trends in intervention effects on intrinsic capacity. The tool assesses six domains of intrinsic capacity. Each domain is scored as 1 if no impairment is identified and 0 if impairment is present, yielding a total score ranging from 0 to 6, with higher scores indicating better intrinsic capacity.
• Health Self-Efficacy [Assessed across 3 time-points: Baseline (T0): within 2 weeks before the first intervention session. Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: Health self-efficacy will be assessed using the Self-Rated Abilities for Health Practices Scale (SRAHP). The SRAHP consists of 28 items assessing self-perceived ability to perform health-promoting behaviours across four domains: exercise, nutrition, responsible health practices, and psychological well-being. Total scores range from 0 to 112, with higher scores indicating greater health self-efficacy for health-promoting practices.
• Social Isolation [Assessed across 3 time-points: Baseline (T0): within 2 weeks before the first intervention session. Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: Social isolation will be assessed using the Social Isolation Scale (SIS). The SIS consists of 6 items assessing the size and quality of participants' social relationships and social connectedness. Total scores range from 6 to 30, with higher scores indicating lower levels of social isolation (greater social connectedness) and lower scores indicating greater social isolation.
• Caregiver burden [Assessed across 3 time-points: Baseline (T0): within 2 weeks before the first intervention session. Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: Caregiver burden will be assessed using the 4-item Zarit Burden Interview (ZBI-4). The ZBI-4 consists of 4 items assessing the perceived impact of caregiving on the caregiver's time, stress, strain, and uncertainty. Total scores range from 0 to 16, with higher scores indicating greater caregiver burden.
• Resource Awareness and Navigation [Assessed across 3 time-points: Baseline (T0): within 2 weeks before the first intervention session. Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: This outcome will be assessed using a study-specific 2-item questionnaire developed for this pilot study. The questionnaire evaluates participants' awareness of caregiving support services and confidence in accessing caregiving support when needed. Each item is rated on a 5-point Likert scale (1 = strongly disagree to 5 = strongly agree). Total scores range from 2 to 10, with higher scores indicating greater awareness and confidence in accessing caregiving support resources.

Other outcomes

• Exploratory digital engagement outcomes [Assessed at Post-intervention (T1): within 2 weeks after completion of the 8-week intervention.]: Assessed using AI chatbot usage analytics, including interaction time, frequency, query categories and click-through rates for recommended resources.
• Intracluster Correlation Coefficient for Future Trial Planning [Assessed across 3 time-points: Baseline (T0): within 2 weeks before the first intervention session. Post-intervention (T1): within 2 weeks after completion of the 8-week intervention. Follow-up (T2): within 2 weeks after the 3-month follow-up time point.]: Estimated for key feasibility and exploratory outcome measures to inform sample size calculation and design considerations for a future definitive cluster randomized controlled trial.

Sex: All, ages: 60 Years to 85 Years, accepts healthy volunteers

Inclusion Criteria:

* Be aged 60 to 85 years;
* Reside in the community;
* Be attending a participating Lions Befrienders Active Ageing Centre;
* Be able to communicate in English or Mandarin;
* Have an Abbreviated Mental Test (AMT) score of 8 or above;
* Self-identify as an informal caregiver providing unpaid care to a family member, friend, or other individual;
* Provide care to a care recipient with impairment in at least one activity of daily living, as assessed using the Older Americans Resources and Services Activities of Daily Living (OARS-ADL) scale;
* Have at least weekly contact with the care recipient.

Exclusion Criteria:

* Have severe visual or hearing impairment that would prevent participation in study activities;
* Have a known diagnosis of dementia or other severe cognitive impairment;
* Have a known diagnosis of a severe psychiatric disorder that may impair study participation (e.g., psychotic disorders);
* Have an AMT score below 8;
* Provide care primarily to grandchildren or children under 18 years of age, rather than to an adult with functional impairment.