Background
Young-onset dementia (YOD) is defined as dementia with debut of symptoms before the age of 65 years. Persons who develop YOD and their families may experience strain related to their life-stage specific circumstances. However, few studies have explored quality of life (QOL) in YOD, and no previous study has assessed QOL in a longitudinal perspective.
Aims
The aims of this project were to assess QOL throughout two years of follow-up in persons with young-onset Alzheimer’s dementia (YO-AD) and frontotemporal dementia (YO-FTD) and their family carers, along with factors associated with QOL changes and differences between the two diagnostic groups. For a broader perspective, baseline QOL was also compared to QOL of persons with late-onset dementia (LOD) and their family carers.
Methods
This was a two-year prospective observational cohort study of persons with YO-AD (n = 50) and YO-FTD (n = 38) and their family carers. The persons with YOD had to be communitydwelling, below the age of 70 at time of inclusion, able to provide informed consent and have regular face-to-face contact with their family carers on a weekly basis. The dyads were recruited from nine Nordic memory clinics. The comparison group consisted of dyads of community-dwelling persons with LOD (n = 100), age 70 years and above, recruited in a previous Norwegian study.
QOL of the persons with dementia was assessed by the proxy version of the Quality of life – Alzheimer’s Disease (QOL-AD). The family carer was instructed to apply the perspectives of the person with dementia. The same questionnaire was also used to assess QOL of the family carers.
Linear mixed model was used to explore factors associated with QOL-AD. Growth mixture models were estimated to detect groups of individuals following different trajectories in QOLAD. Logistic regression was applied to determine baseline characteristics significantly associated with belonging to the poorer versus better QOL group. Linear regression models were estimated to explore variables associated with QOL-AD in the comparisons of YOD and LOD.
Results
We found QOL in persons with YOD to be better compared to persons with LOD. Depressive symptoms and unmet needs were associated with poorer QOL in persons with YOD. Although baseline data did not show significant differences in QOL-AD scores between the two diagnostic groups, the longitudinal analyses showed poorer QOL in persons with YOFTD at all time points.
For family carers the situation was reversed, as carers of persons with YOD had poorer QOL compared to carers of persons with LOD. Poorer QOL of family carers of persons with YOD was associated with more carer burden and depressive symptoms of the carer, more depressive symptoms of the person with YOD and longer symptom duration. Increased carer burden at baseline was associated with belonging to the poorer QOL group. Although baseline data did not show significant differences in QOL between carers of persons with YO-AD and YO-FTD, the longitudinal analyses showed that family carers of persons with YO-AD and male carers had poorer QOL at one- and two-year follow-up.
Conclusion
Persons with YOD had better QOL compared to persons with LOD, while their family carers reported poorer QOL compared to family carers of persons with LOD. Persons with YO-FTD had poorer QOL compared to persons with YO-AD during follow-up. However, a diagnosis of YO-AD may have greater impact to carer QOL compared to YO-FTD. We also found male carers to have poorer QOL compared to female carers. Depressive symptoms were associated with poorer QOL in persons with YOD and their family carers, as for persons with LOD and their family carers.