The participants in the control group will receive only sleep hygiene (one-page handout) via WeChat. Access to the CBT-I WeChat mini program will be offered to these participants after the completion of the 3-month follow-up assessment.

The caregiver burden will be evaluated by Zarit Burden Interview-12 (ZBI-12). The ZBI-12 is a widely used, 12-item shortened version of the original ZBI, designed to assess the subjective burden experienced by informal caregivers. Total scores range from 0 to 48, with higher scores indicating a greater level of caregiver burden.

Depressive symptoms will be assessed using the Patient Health Questionnaire-9 (PHQ-9). The PHQ-9 is a widely used, 9-item questionnaire designed to screen for, diagnose, monitor, and measure the severity of depression. Each item evaluates the frequency of depressive symptoms experienced over the past two weeks. Total scores range from 0 to 27, with higher scores indicating more severe depressive symptoms.

Anxiety symptoms will be assessed using the Generalized Anxiety Disorder-7 (GAD-7). This self-administered, 7-item questionnaire was designed as a screening tool and a severity measure for GAD. Each item asks about the frequency of anxiety symptoms over the past two weeks. Scores range from 0 to 21, with higher scores indicating more severe anxiety symptoms.

Fatigue will be assessed using the Multi-Dimensional Fatigue Inventory (MFI). The MFI is a 20-item self-report questionnaire designed to measure five dimensions of fatigue (i.e., general fatigue, mental fatigue, physical fatigue, reduced activity, and reduced motivation). Total scores range from 20 to 100, with higher scores indicating greater levels of fatigue.

Health-related quality of life will be assessed using the five-dimension five-level European Quality of Life scale (EQ-5D-5L). The EQ-5D-5L is a standardized questionnaire designed to evaluate five dimensions of health: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The EQ-5D-5L score ranges from -0.39 to 1, with higher scores indicating better quality of life. Additionally, the EQ-5D-5L includes a Visual Analog Scale (VAS) for overall self-rated health status, with scores ranging from 0 to 100, where higher scores represent better health-related quality of life.

The participants' perspectives of acceptability and satisfaction will be evaluated using eight adapted items from the Acceptability E-scale. Each item is rated on a 5-point Likert scale, with scores ranging from 1 to 5. The total score ranges from 8 to 40, with higher scores indicating greater acceptability and satisfaction with the intervention.

All adverse events reported by the participants will be documented.

The delivery of the intervention will be assessed via semi-structured qualitative interviews conducted with trial participants after the intervention. Intervention adherence will also be assessed by the number of sessions completed on the WeChat mini program and the number of weekly nurse support sessions attended by participants.

The Intervention acceptability will be assessed via semi-structured qualitative interviews conducted with trial participants after the intervention.

Throughout the study, all nurse support sessions will be recorded. A random sample of 20% of the sessions will be evaluated by a psychologist for treatment fidelity using a modified version of the Yale Adherence and Competence Scale.