A multistate transition model of changes in loneliness and carer stress among community-dwelling older adults in Aotearoa New Zealand

To identify changes in loneliness and carer stress between two time points for older people of different ethnicities who had repeated interRAI home care assessments. Participants consisted of community-dwelling older adults across New Zealand who received two interRAI-HC assessments between 5 July 2012 and 31 December 2019. Two multistate models were developed: the first model was not lonely versus lonely, and the second model was no carer stress versus carer stress. The one-year transition probabilities were calculated. Mean sojourn times were calculated for each state except death. Paired t-tests assessed the differences in transition probabilities between the different ethnic groups. The mean age of the cohort was 82.5 years (SD 7.7 years). At first assessment, 14,646 (21%) older people stated they were lonely and 26,789 carers (38%) experienced stress. The most common first transition type was not lonely to not lonely: Māori 42%, Pacific 54%, Asian, 48% and Other 40%. The highest one-year transition probability in the loneliness model was living in aged residential care to death (0.79). The most common first transition type for the carer stress was no carer stress to no carer stress: Māori 35%, Pacific, 46%, Asian, 43% and Other 33%. The highest one-year transition probability in the carer stress model was living in aged residential care to death (0.80). The statuses not lonely and no carer stress had a mean sojourn time of approximately one year, and eight months to one year, respectively. Loneliness can change over time due to circumstances and an individual's perception of loneliness at the time of assessment. Carer stress is enduring and has a low probability of improvement.