OBJECTIVES : Existing preference-based quality of life (QoL) measures focus mainly on health. However, when evaluating care services for older adults improving health is often not the main outcome of care. Therefore, there is a need for preference-based QoL measures with a broader perspective on QoL, such as the ASCOT-SCT4. This abstract presents the Dutch utility tariff for the ASCOT-SCT4.

METHODS : Best-worst scaling (BWS) and composite time trade off (TTO) experiments were conducted among representative samples of the Dutch population. BWS data were analysed using a multinomial logit model with robuststandard errors based on the sandwich estimator. To anchor values on the traditional 0-1 utility scale a mapping approach ombining the BWS data with the TTO data was used.

RESULTS : A total of 870 respondents who completed the BWS internet survey, were included. The top two levels of the ASCOT-SCT4 domains Control over daily lifeand Occupationwere most often chosen as the best domain levels. The worst level of the domains Control over daily life, Personal safetyand Dignitywere most often chosen as the worst domain levels. The estimated BWS coefficients of all domain levels were positive and showed a logically consistent order. Observed mean TTO values for the 26 ASCOT profiles included in the TTO experiment ranged from -0.446 to 0.960. The mean observed value was negative for 6 of the 26 profiles. The predicted Dutch ASCOT-SCT4 values range from -0.277 for the worst ASCOT-SCT4 profile to 1 for the best ASCOT-SCT4 profile.

CONCLUSIONS : The results of this study provide estimates for the preferences of the Dutch general population for ASCOT-SCT4 quality of life profiles and the resulting population level tariff. This tariff can be used to calculate a social care QALY equivalent that can be used to estimate the impact of social care interventions.