The CASP-19 as a measure of quality of life in old age: evaluation of its use in a retirement community.
OBJECTIVE
The CASP-19 is a quality-of-life measure comprising four domains ('control', 'autonomy', 'pleasure' and 'self-realization'), developed initially in a population aged 65-75 years. This study tested the scale for use in a population whose demographic profile and residential status differed markedly from the original population.


METHODS
CASP-19 data were gathered from 120 residents of a U.K. retirement community. Distribution of scores, factor structure, internal consistency and construct validity were examined.


RESULTS
Scores were negatively skewed, especially on the pleasure domain. Attempts to confirm the factor structure of the scale were equivocal. Coefficients for composite reliability ranged from 0.52 to 0.84 across domains. Some items, particularly in the control and autonomy domains, showed low correlations with their domains. The CASP-19 correlated with the Diener Satisfaction with Life Scale (r = 0.66), and the physical (r = 0.53) and mental (r = 0.49) component summaries of the SF-12, supporting its construct validity. A recently proposed 12-item version of the scale appears to have superior dimensionality.


CONCLUSIONS
Although in some respects the CASP-19 exhibited good psychometric properties, the internal consistency and dimensionality of the control and autonomy domains are suspect. Further modification of the scale may be fruitful from a psychometric point of view.
Centre for Social Gerontology, Keele University, Staffordshire, ST5 5BG, UK. j.sim@keele.ac.uk
Julius
J
Sim
Bernadette
B
Bartlam
Miriam
M
Bernard
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010549:Personal Satisfaction; D011594:Psychometrics / Q000295:instrumentation; D011788:Quality of Life; D012112:Residential Facilities; D011795:Surveys and Questionnaires / Q000592:standards*; D006113:United Kingdom
Med Care. 1996 Mar;34(3):220-33
8628042
Gerontologist. 2003 Oct;43(5):628-37
14570959
J Pers Assess. 1985 Feb;49(1):71-5
16367493
Health Expect. 1999 May;2(2):93-104
11281883
Br J Math Stat Psychol. 2008 Nov;61(Pt 2):275-85
17535482
Aging Ment Health. 2003 May;7(3):186-94
12775399
Psychometrika. 2009 Mar;74(1):107-120
20037639