An assessment of the construct validity of the ASCOT measure of social care-related quality of life with older people

Abstract

BackgroundThe adult social care outcomes toolkit (ASCOT) includes a preference-weighted measure of social care-related quality of life for use in economic evaluations. ASCOT has eight attributes: personal cleanliness and comfort, food and drink, control over daily life, personal safety, accommodation cleanliness and comfort, social participation and involvement, occupation and dignity. This paper aims to demonstrate the construct validity of the ASCOT attributes.MethodsA survey of older people receiving publicly-funded home care services was conducted by face-to-face interview in several sites across England. Additional data on variables hypothesised to be related and unrelated to each of the attributes were also collected. Relationships between these variables and the attributes were analysed through chi-squared tests and analysis of variance, as appropriate, to test the construct validity of each attribute.Results301 people were interviewed and approximately 10% of responses were given by a proxy respondent. Results suggest that each attribute captured the extent to which respondents exercised choice in how their outcomes were met. There was also evidence for the validity of the control over daily life, occupation, personal cleanliness and comfort, personal safety, accommodation cleanliness and comfort, and social participation and involvement attributes. There was less evidence regarding the validity of the food and drink and dignity attributes, but this may be a consequence of problems finding good data against which to validate these attributes, as well as problems with the distribution of the food and drink item.ConclusionsThis study provides some evidence for the construct validity of the ASCOT attributes and therefore support for ASCOT's use in economic evaluation. It also demonstrated the feasibility of its use among older people, although the need for proxy respondents in some situations suggests that developing a version that is suitable for proxies would be a useful future direction for this work. Validation of the instrument on a sample of younger social care users would also be useful.

Outcomes of social care for adults: developing a preference-weighted measure.

“…With the exception of marital status, the pattern of these associations is the same for equipment users as it is for older home care recipients. 83 Interestingly, marital status showed the opposite pattern of results to those found previously, being significantly, positively associated with accommodation cleanliness and comfort and not at all related to the food and drink domain. This may reflect differences between the two samples.…”

“…The comparison of the individual items with variables reflecting themes hypothesised to be associated with each SCRQoL domain is reported in detail elsewhere. 83 In general, where we anticipated relationships, these were found, with strong relationships between our measure and indicators of well-being (as measured by GHQ-12) and control and autonomy (as measured by the subscale of CASP-12), and the attributes as we would hope ( Table 5). A few findings were unanticipated, but these could be plausibly explained.…”

Comparing Measurement Properties of the EQ-5D-3L, ICECAP-O, and ASCOT in Frail Older Adults

“…ASCOT was developed in the United Kingdom as well and includes a PBM for use in economic evaluations that measure social care-related quality of life [13,18]. ASCOT covers eight domains, varying from basic aspects such as personal cleanliness and feeling safe to higher order aspects such as social participation, occupation, dignity, and control over daily life.…”

Czech version of OPQOL-35 questionnaire: the evaluation of the psychometric properties

“…There are six of them. If we sort them by the year of their origin, we get this order: CASP-19 – Control, Autonomy, Self-Regulation, Pleasure [11], WHOQOL-OLD – World Health Organization Quality of Life – Old [12], QUAL-E – Quality of Life at the End of Life [13], EQOLI – Elderly Quality of Life Index [14, 15], OPOQOL - Older People’s Quality of Life Questionnaire [16], ASCOT – Adult Social Care Outcomes Toolkit [17]. When considering which one to choose, we have ruled out three of them at once: ASCOT questionnaire because it is designed primarily to assess the social, not medical care; EQOLI questionnaire, the development of which has not yet been completed and the questionnaire QUAL-E, because it focuses on specific period - the quality of life at the end of life.…”