The psychometric properties of the control, autonomy, self-realisation and pleasure scale (CASP-19) for older adults with dementia

Introduction: Asset based approaches to dementia research and measurement emphasise the need to also assess the strengths and capabilities that people with dementia retain, rather than assessing only losses or deficits. The CASP-19 proposes wellbeing as the satisfaction of four needs' (control, autonomy, self-realisation and pleasure). The CASP-19 may reflect the asses-based approach and has been validated in over 20 countries. The aim of this study was to evaluate the CASP-19's psychometric properties in older adults with dementia.Methods: An observational study was conducted at five NHS trusts across England. Participants were asked to either complete the CASP-19 by interview or self-report, alongside four other measures to assess psychometric properties.Results: Internal consistency overall was good ( = .856) but the autonomy subscale fell below the acceptable. The CASP-19 was significantly correlated in the expected direction with measures of quality of life (r = .707), depression (r = -.707) and additional measures. It also remained moderately stable over a one-week period but factor analyses indicated a 12-item measure may be more robust.Conclusions: Despite some variations, the CASP-19 appears to have adequate psychometric properties for older adults with dementia and can be used in future research and practice.