Population-based preference weights for the Adult Social Care Outcomes Toolkit (ASCOT) for Service Users for Austria: findings from a best-worst experiment

Background: The Adult Social Care Outcomes Toolkit (ASCOT) measures quality-of-life (QoL) outcomes of long-term care (LTC) service provision. Country-specific preference weights are required to calculate ASCOT scores. ASCOT has been translated into German, but lacks preference weights for German-speaking countries. Objectives: This paper aims to establish Austrian preference weights for the German version of the ASCOT service user measure, using best-worst scaling (BWS). Methods: Data were collected using an online BWS-experiment from a general population sample (n=1,000) of Austrian adults. We use a scaleadjusted multinomial logit model (S-MNL) accounting for positioning effects to estimate preference weights. Results: Austrians value the top attribute-levels in the ASCOT domains 'being meaningfully occupied during the day' and 'having control over daily life' most highly, whereas high needs were the least preferred in the domains 'dignity' and 'social participation'. From a methods perspective, we found significant positioning effects only for 'best' choices, with statements at the top of a list being picked more often than those further down in the list. Factors related to survey completion (self-assessed understanding of the tasks and survey completion time) were shown to have the greatest effect on individual choice consistency. Discussion: The paper provides Austrian preference weights for the German version of ASCOT for service users. The weights also provide insight into how Austrians value different LTC-QoL states. Future research may investigate how values for different LTC-QoL states differ between socioeconomic groups

Rasch analysis of the long-term conditions questionnaire (LTCQ) and development of a short-form (LTCQ-8)

Background The aim of the current study was to evaluate the structural validity of the 20-item long-term conditions questionnaire (LTCQ) and to explore a potential short-form version of the scale using Rasch analysis. Methods Data were collected through postal surveys (February 2016–January 2017) from a sample of 1,211 participants diagnosed with at least one long-term condition (LTC). Identified participants were invited through either local authorities for a social care cohort (n = 294) or primary care practices for a health care cohort (n = 917). Participants were mailed a survey, including the LTCQ, demographic questions, a comorbidities measure, and other validated outcome measures. Respondents were invited to complete a follow-up survey including the LTCQ for assessment of reproducibility. Results The main assumptions of the Rasch model from the LTCQ were fulfilled, although infit and outfit indices indicated some items showed misfit. Misfitted items, items that did not have a preceding set or showed some local dependence were removed one at a time, with the remaining candidate items to form an 8-item short version, the LTCQ-8. The Rasch model for the LTCQ-8 explained 64% variance and had a reliability estimate greater than 0.80. Several items in the LTCQ showed uniform differential item function (DIF) in relation to the number of reported LTCs, age, cohort and type of LTCs, but fewer items exhibited DIF in the LTCQ-8. Spearman’s rho correlations between the LTCQ and the LTCQ-8 were strong across the total sample and various subgroups. Correlations between the LTCQ-8 and all reference measures were moderate to strong, and comparable to correlations found between the LTCQ and these measures. Conclusions The LTCQ measures a unidimensional construct, and it is therefore acceptable to use a summed total score. The LTCQ-8 also met the assumption of unidimensionality and had comparable construct validity with the LTCQ. Additional validation is required in an independent sample

Comparing internet and face-to-face surveys as methods for eliciting preferences for social care-related quality of life: Evidence from England using the ASCOT service user measure

Purpose: Traditionally, researchers have relied on eliciting preferences through face-to-face interviews. Recently, there has been a shift towards using internet-based methods. Different methods of data collection may be a source of variation in the results. In this study, we compare the preferences for the Adult Social Care Outcomes Toolkit (ASCOT) service user measure elicited using best-worst scaling (BWS) via a face-to-face interview and an online survey. Methods: Data were collected from a representative sample of the general population in England. The respondents (face-to-face: n=500; online: n=1,001) completed a survey, which included the BWS experiment involving the ASCOT measure. Each respondent received eight best-worst scenarios and made four choices (best, second best, worst, second worst) in each scenario. Multinomial logit regressions were undertaken to analyse the data taking into account differences in the characteristics of the two samples and the repeated nature of the data. Results: We initially found a number of small significant differences in preferences between the two methods across all ASCOT domains. These differences were substantially reduced – from 15 to five out of 30 coefficients being different at the 5% level – and remained small in value after controlling for differences in observable and unobservable characteristics of the two samples. Conclusions: This comparison demonstrates that face-to-face and internet surveys may lead to fairly similar preferences for social care-related quality of life when differences in sample characteristics are controlled for. With or without a constant sampling frame, studies should carefully design the BWS exercise and provide similar levels of clarification to participants in each survey to minimise the amount of error variance in the choice process

Development of Japanese utility weights for the Adult Social Care Outcomes Toolkit (ASCOT) SCT4

Purpose: In developed countries, progressive rapid aging is increasing the need for social care. This study aimed to determine Japanese utility weights for the Adult Social Care Outcomes Toolkit (ASCOT) four-level self-completion questionnaire (SCT4). Methods: We recruited 1050 Japanese respondents from the general population, stratified by sex and age, from five major cities. In the best–worst scaling (BWS) phase, respondents ranked various social care-related quality of life (SCRQoL) states as “best,” “worst,” “second-best,” or “second-worst,” as per the ASCOT. Then, respondents were asked to evaluate eight different SCRQOL states by composite time-trade off (cTTO). A mixed logit model was used to analyze BWS data. The association between cTTO and latent BWS scores was used to estimate a scoring formula that would convert BWS scores to SC-QALY (social care quality-adjusted life year) scores. Results: Japanese BWS weightings for ASCOT-SCT4 were successfully estimated and found generally consistent with the UK utility weights. However, coefficients on level 3 of “Control over daily life” and “Occupation” domains differed markedly between Japan and the UK. The worst Japanese SCRQoL state was lower than that for the UK, as Japanese cTTO results showed more negative valuations. In general, Japanese SC-QALY score (for more than 90% of health states) was lower than that for the UK. Conclusions: We successfully obtained Japanese utility weights for ASCOT SCT4. This will contribute to the measurement and understanding of social care outcomes

Do you prefer safety to social participation? Finnish population-based preference weights for the Adult Social Care Outcomes Toolkit (ASCOT) for service users

Introduction: The Adult Social Care Outcomes Toolkit (ASCOT) was developed in England to measure people’s social care-related quality of life (SCRQoL). Objectives: The aim of this paper is to estimate preference weights for the Finnish ASCOT for service users (ASCOT-SU). In addition, we tested for learning and fatigue effects in the choice experiment used to elicit the preference weights. Methods: The analysis data (n = 1000 individuals) were obtained from an online survey sample of the Finnish adult general population using gender, age and region as quotas. The questionnaire included a best-worst scaling (BWS) experiment using ASCOT. Each respondent sequentially selected four alternatives (best, worst; second best, second worst) for eight BWS tasks (n = 32,000 choice observations). A scale multinomial logit model was used to estimate the preference parameters and to test for fatigue and learning. Results: The most and least preferred attribute-levels were “I have as much control over my daily life as I want” and “I have no control over my daily life”. The preference weights were not on a cardinal scale. The ordering effect was related to the best choices. Learning effect was in the last four tasks. Conclusions: This study has developed a set of preference weights for the ASCOT-SU instrument in Finland, which can be used for investigating outcomes of social care interventions on adult populations. The learning effect calls for the development of study designs that reduce possible bias relating to preference uncertainty at the beginning of sequential BWS tasks. It also supports the adaptation of a modelling strategy in which the sequence of tasks is explicitly modelled as a scale factor