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

ABSTRACT

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 (α = .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.

KEYWORDS:

• CASP-19
• psychometric
• dementia
• quality of life
• reliability
• validity
• wellbeing
• Alzheimer's
• outcome measurement
• positive psychology

Acknowledgments

The authors would like to thank Professor Esme Moniz-Cook, Dr Catherine Hart, Lauren Sudgen, Amy Shipman, Joanne Sawyer, Lisa Thomson, and Sandra Simpson for their invaluable support and assistance with data collection. We would also like to thank all the people who took part in this study.

Disclosure statement

The authors declare no competing interests.

Additional information

Funding

The current research was funded by a University College London (UCL) Grand Challenge of Human Wellbeing PhD project and was given support by the Clinical Research Network Portfolio (CPMS ID: 30348). The PhD project was linked to the Economic Social Research Council (ESRC)/National Institute for Health Research (NIHR) funded Promoting Independence in Dementia (PRIDE) research programme(ES/L001802/1). No funding bodies were involved in the design, collection, analysis, interpretation or writing of the manuscript. The views expressed are those of the authors and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health.