German tariffs for the ICECAP-Supportive Care Measure (ICECAP-SCM) for use in economic evaluations at the end of life

Purpose Economic evaluations often use tariffs for health-related quality of life to quantify health effects. For wellbeing at the end of life, issues beyond health-related quality of life may be important. Therefore, the ICECAP Supportive Care Measure (ICECAP-SCM) based on the capability approach was developed. The ICECAP-SCM questionnaire consists of seven attributes, each described by four ordinal levels. A validated German version of the ICECAP-SCM was published recently. However, tariffs for the German ICECAP-SCM are not available. Therefore, the aim was to determine a value set for the ICECAP-SCM based on preferences of the German general population.

Methods An online sample of 2996 participants completed a best-worst scaling (BWS) and discrete choice experiment (DCE). BWS requires that participants choose the best and worst option within the same set of end of life attributes, whereas DCE requires that participants make a choice between two end of life sets. The choice data was used to derive tariffs for the ICECAP-SCM capability states. First, BWS and DCE data were analyzed separately. Subsequently, combined data were analyzed using scale-adjusted conditional logit latent class models. Models were selected based on the stability of solutions and the Bayesian information criterion.

Results A model with two latent classes was identified to be optimal for the separate analysis of the BWS and DCE data, and this finding was also stable and consistent for the combined data. Results of the models for the BWS, DCE and combined data were transformed into tariffs scaled between 0 and 1.

Conclusions The German tariffs for the ICECAP-SCM can be used to quantify effectiveness in economic evaluations. The value sets based on BWS data were similar for Germany and the UK, whereas the value set based on combined data varied.

Publication History

Article published online:
02 September 2021