OBJECTIVES: The International Classification of Functioning, Disability & Health is commonly used to measure outcomes in rehabilitation. As other instruments it assigns equal weight to each item. ICF doesn’t distinguish importance and all changes are assumed to have equal relevance. It doesn’t account for how people value improvements. The objective is to examine the extent to which preference-weighted core elements of the ICF differ from unweighted assignments currently used in treatment decisions

METHODS: Three best–worst scaling experiments are used to value body function and activities. ICF dimensions relevant in terms of function (BWS II, 36 items), perception (BWS III, 6 attributes, 3 levels), and activities (BWS I, 34 items) are extracted. Stroke patients as well as members of the public are recruited. Fractional, efficient designs are applied for all surveys (randomization, forced choice). Conditional and multinominal logit analyses are used as the main analysis method.

RESULTS: N=306 participants were recruited until May/June 2022. The study is currently collecting data of the general population. In BWS I, attributes of self-care are valued highest, while community, social & civic life is of less relevance. In BWS II, ensuring gait pattern functions is the short-term focus (SQRT: 1.462), with muscle endurance being least relevant (SQRT: 0.747). In BWS III on neglect the orientation to other persons is most important (LD: 0.3979). The value gained while transiting from worst to best level is highest.

CONCLUSIONS: If improvements of functions have effects on activities and these have effects in terms of health-related quality of life raises the question how the value of functions can be measured? The preliminary results show that unlike in the ICF body functions and activities are not equally weighted by those affected. Results reveal differences between patient/public judgements and current clinical practice where all outcomes are equal. This enhances the need for preference-based outcome evaluations.