Carer social care-related quality of life outcomes: estimating English preference weights for the Adult Social Care Outcomes Toolkit for Carers (ASCOT-Carer)

Objective: To estimate preference-based index values for the English version of the ASCOT-Carer, a measure assessing social care-related quality of life (SCRQoL) in informal carers, from the general population in England.

Methods: The ASCOT-Carer consists of seven domains, each reflecting aspects of SCRQoL in informal carers. Preferences for the ASCOT-Carer SCRQoL states were estimated using a Best-Worst Scaling exercise (BWS) in an online survey. The survey was administered to a sample of the general adult population in England (n=1,000). Participants were asked to put themselves into the hypothetical state of being an informal carer and indicate which attribute they thought was the best (first and second) and worst (first and second) from a profile list of seven attributes reflecting the seven domains, each ranging at a different level (1-4). Multinomial logistic regression was used to analyse the data and estimate preference weights for the ASCOT-Carer measure.

Results: The most valued aspect by English participants was the ‘occupation’ attribute at its highest level. Results further showed participants rated having ‘no control over their daily life’ as the lowest attribute-level of all those presented. The position of the seven attributes influenced participants’ best and worst choices, and there was evidence of both scale and taste heterogeneity on preferences.

Conclusions: This study has established a set of preference-based index values for the ASCOT-Carer in England derived from the BWS exercise that can be used for economic evaluation of interventions on older individuals and their informal carers.