Methods

Settings/participants: In Argentina, Mexico, Peru, Dominican Republic, India and China, we are carrying out a formal randomised controlled trial of the caregiver intervention; all people with dementia identified in the population-based survey (and their principal caregivers) will be offered randomisation to receive the caregiver training and education intervention either a) immediately or b) after 6 months, that is after the final outcome assessments have been completed. The principal caregiver is the family member or close friend who is most involved in providing and/or organising care for the person with dementia. Paid caregivers and/or other family caregivers may participate in the intervention but are not subject to the outcome assessment.

Inclusion/exclusion criteria: The inclusion criterion is a 10/66 algorithm diagnosis of dementia. Exclusion criteria are serious intercurrent illness in the person with dementia, or absence of family caregivers.

Procedures: Consent is obtained from the person with dementia, where possible, and their principal caregiver. In the pre-randomisation visit, a research worker completes the baseline assessments (see below), explains the trial and seeks informed consent from the person with dementia and the caregiver. Randomisation is carried out in London, and the codes transmitted to the local 10/66 centre by fax or e-mail. Randomisation is by permuted block to ensure in each centre an even distribution of baseline caregiver strain.

Outcomes:The intervention in all centres will be evaluated in terms of uptake and completion rates, together with before (baseline) and after (six months) intention to treat comparisons of standard assessments. Principal outcomes related to the caregiver are caregiver role strain (Zarit caregiver burden interview), psychological distress (SRQ 20), and quality of Life (the 17 item WHO-QoL Bref) (11). Principal outcomes related to the person with dementia are behavioural and psychological symptoms of dementia (Neuropsychiatric Inventory – NPI-Q) (12) and quality of life (DEMQoL) (13). The clinician (if any) responsible for clinical care of the person with dementia will be blind to the intervention. They may organise any supplementary care that they feel is indicated. The assessor, assessing outcome after the intervention will be blind to the intervention. The family, and the assessor will be asked to do everything they can to maintain blindness.

Analyses:Primary endpoint analysis will be according to intention to treat with last observation carried forward for missing data. Failures of randomization would be adjusted for as factors or covariates, using generalized linear modelling. In each centre, with 30 families randomised to the control and intervention arms, the study is powered to detect moderate effect sizes (0.8 or greater for change scores on continuously distributed outcomes) associated with the intervention, at 80% power and 95% confidence. Data from the different centres will, later, be subject to meta-analysis.