The development and validation of the Dementia Quality of Life Scale for Older Family Carers (DQoL-OC).

PURPOSE: Little is known about how caregiving affects the quality of life (QoL) of older family carers and no dementia and age-specific QoL scale is available for use with this population. This study aimed to develop and validate a unique dementia caregiving- and age-specific tool - the 'Dementia Quality of Life Scale for Older Family Carers' (DQoL-OC).

METHODS: The scale items were identified in focus groups with older family carers in the UK. Content and face validity were evaluated by a panel of six experts. A set of 100 items assessed on a 5-point Likert scale was tested with 182 older family carers. Test-re-test reliability was conducted with 18 individuals. Exploratory factor analysis was used to identify the QoL model and reduce the number of scale items. Convergent construct validity and internal consistency were also established.

RESULTS: A one-factor solution containing 22 items was obtained. Test-re-test reliability (lower bound r = 0.835; p < 0.001), internal consistency (Cronbach's α = 0.936), and convergent construct validity were established. Significantly lower levels of QoL were found in female older carers; those who perceived their relatives with dementia as being at the earlier stages of the disease and with unstable dementia symptoms; those providing care more hours per day and more days per week; and those in younger-old age.

CONCLUSIONS: The DQoL-OC is a valid and reliable scale that will be useful for research and in clinical practice with older family carers of people with dementia. These study results will inform future health and social care aiming to improve life quality for this overlooked population of carers.