Developing and Evaluating a Digital Intervention Aiming to Support Informal Caregivers of People With Dementia

Number of participants enrolled divided by number of eligible individuals. Registered by a project nurse at the recruiting clinic

Number of full surveys returned at follow-up divided by total number of participants. Assessed in the REDCap database where all survey data are gathered.

Satisfaction, relevance, perceived value, ease of use, key barriers and facilitators for use, suggestions for improvement of the CARE-Dem. Assessed through semi-structured, qualitative interviews with participants in the intervention group.

Assessed through semi-structured, qualitative interviews with all professionals involved in re-cruitment and randomisation.

Number of completed survey items at follow-up divided by total number of items. Only surveys filled in at baseline and end of intervention are counted. Assessed in the REDCap database where all survey data are gathered.

Assessed through semi-structured, qualitative interviews with all participants in the intervention group.

Proportion of intervention components completed by each participant within three months. Collected via participant logs, where all interaction with the intervention will be documented by participants in the intervention group.

Evaluated by comparing observed mean change scores from baseline to end of intervention with effect sizes reported in previous studies of digital interventions for informal caregivers of people with dementia. Feasibility will be considered acceptable if observed changes in the intervention group from baseline to end of intervention are in the expected direction and within the range of small-to-moderate effects (Cohen's d ≥ 0.20), consistent with similar studies of digital interventions for informal caregivers of people with dementia.

Assessed via short interviews with recruiting nurses who collect accounts from participants in the intervention group and participants in the control group.

Assessed through interviews with participants who do not complete the intervention within the designated three months. We aim to interview as many as possible among participants who drop out or do not complete the intervention.

Measured with the Zarit Burden Interview (ZBI), a 22-item questionnaire including four aspects of caregiver burden: personal strain, role strain, impact on social life, and impact on personal health. Items are rated on a 5-point Likert scale ranging from 0 (never) to 4 (nearly always) with total scores ranging from 0 to 88.

Measured with the World Health Organization 5-Item Well-Being Index (WHO-5), a 5-item ques-tionnaire concerning feelings about everyday life in the previous two weeks. Items are rated on a 6-point Likert scale ranging from 0 (at no time) to 5 (all the time). The raw score ranges from 0 to 25 and is converted to a percentage score from 0 to 100.

Measured with the General Self-Efficacy Scale (GSES), a 10-item questionnaire assessing per-ceived ability to cope with challenging and demanding situations. Items are rated on a 4-point Lik-ert scale from 1 (not at all true) to 4 (exactly true) with total scores ranging from 10 to 40.

Participants' experiences of knowledge and benefits acquired from using the intervention, particularly regarding impact on the quality of their relation to the person with dementia, experiences of being able to accept the situation, and feelings of being capable of managing their caregiving role. Assessed through qualitative interviews with participants in the intervention group.