Development and effectiveness of a user-centered mobile application for informal caregivers of people living with dementia: randomized controlled trial

BACKGROUND: Dementia places substantial physical, psychological, and social demands on informal caregivers, and caregiving needs may change across the dementia trajectory as cognitive, behavioral, and functional changes alter day-to-day care demands. Digital interventions may not fully address caregivers' evolving and heterogeneous needs and preferences. This study aimed to develop a user-centered mobile application informed by caregiver-identified needs and preferences across the dementia trajectory and to evaluate its effectiveness. METHODS: A randomized controlled trial was conducted following a qualitative intervention-development phase. The intervention was developed in accordance with the Medical Research Council framework for complex interventions and informed by principles of person-centered dementia care and qualitative interviews with informal caregivers. The application provided dementia education; communication and daily-care guidance organized to reflect changing caregiving needs; guidance for behavioral and psychological symptoms; caregiver self-care and stress-management resources; information on formal and informal support services; and customizable reminders. Caregivers were randomized to receive usual care with access to the mobile application for 8 weeks or usual care alone. Outcomes included caregiver burden (Zarit Burden Interview), quality of life (WHOQOL-BREF), neuropsychiatric symptoms (Neuropsychiatric Inventory), and caregiver distress related to these symptoms. System usability was assessed post-intervention in the intervention group. Outcomes were assessed at baseline and week 8 using repeated-measures analysis of variance. RESULTS: A total of 86 caregivers were randomized, of whom 75 were included in the analysis (intervention, n = 37; control, n = 38). Significant group-by-time interactions were observed for overall quality of life (p < 0.001) and the psychological domain (p < 0.001), with greater improvements in the intervention group than in the control group. No significant group-by-time interactions were observed for caregiver burden, neuropsychiatric symptom severity, or caregiver distress. The application demonstrated good usability at week 8. CONCLUSIONS: The user-centered mobile application was associated with improvements in overall and psychological quality of life among participants included in the 8-week analysis, while no significant intervention effects were observed for caregiver burden, neuropsychiatric symptoms, or caregiver distress. Larger studies with longer follow-up and more detailed assessment of application engagement are needed to evaluate the durability and broader effects of the intervention. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov (Registration number: NCT06179667 , Date of registration: 27 November 2023).