Aim: To assess the clinical and economic effectiveness of an approach based on the meanings of vocal behaviours (VB) in older people living with Alzheimer's disease or related disorders (ADRD) in long-term care facilities (LTCF) using a pragmatic randomized trial complemented by a qualitative component. Background: Vocal behaviours are common in LTCF; 13 to 60% of residents exhibit them. They may indicate ill-being, are associated with overmedication, are disruptive for others, and induce powerlessness in family and formal caregivers. Studies on interventions to reduce VB have shown limited clinical impacts. In previous projects, the investigators developed and pilot tested a novel approach based on the underlying meanings of VB. The systematic approach comprises family-formal caregivers' partnerships which include regular meetings (at least monthly) to identify the meanings behind VB (e.g. pain, anxiety) and to apply personalized interventions (e.g. gardening, humor). A pilot study conducted in five LTCF demonstrated the feasibility and acceptability of the recruitment and data collection methods, as well as the approach implementation using 14 triads, each made up of an older person with ADRD, a family caregiver and a formal caregiver. The approach decreased the frequency of VB, and increased the well-being of the older people with ADRD. The formal and family caregivers perceived the VB as less disruptive, and felt more empowered relative to them. However, the lack of control group precluded measuring effectiveness versus usual practices and costs. Methods: A pragmatic cluster randomized trial will be conducted to assess the effectiveness of the approach based on the results from the pilot study. A concomitant qualitative component will describe process elements that contribute to the measured effects. The investigators will randomize 20 LTCF to either an experimental (approach) or control group (usual practices), and recruit 6 triads in each LTCF for a total of 108 triads (power of 80%, significance 5%, medium effect size and 40% attrition). They will enroll 10 to 20 triads in the qualitative component. They will collect data, before, two (post-implementation) and four months (follow-up) after starting the implementation of the approach, on VB frequency (primary outcome), medication use, well-being of the older people, perceived disruptiveness of the VB, the partnership-based decision-making and the level of empowerment felt by family and formal caregivers. Additionally, they will collect data on the setting (e.g. number of beds, turnover rate), and cost (e.g. trainer, medication). Qualitative data will also be collected with individual semi-structured interviews. The investigators will analyze the effects of the approach using a mixed-model of covariance with baseline measures, and characteristics of participants and settings as covariates. They will also calculate a cost-effectiveness ratio, and do a content analysis of qualitative data. Expected outcomes: This project will provide evidence on the effectiveness of a novel and generalizable approach to increase the well-being of vulnerable older people, as well as family and formal caregivers. If effective, it may be implemented on a larger scale and adapted to other behaviours (e.g. aggressive behaviours), all of which is aligned with recommendations for research in dementia care.