The value of freedom: the development of the WeRFree capability instrument

The capability approach has been used to develop instruments. However, the capability concept by Sen has been argued to be ambiguous concerning some elements of freedom, such as the burdens that people experience whilst achieving capabilities. Developing instruments with a comprehensive definition of capability might increase their sensitivity to a broader range of constructs. Our study operationalizes a framework based on the comprehensive "option freedom" concept into measurable constructs and presents an illustrative instrument. For this, the Multi Instrument Comparison (MIC) database was used. Items from the MIC database were matched to themes from a framework that had been developed in an earlier qualitative study. Then, a measurement model was constructed with the selected items and model fit was assessed. Lastly, an illustrative instrument was created that shows how the selected constructs can be measured concisely. A measurement model was constructed with 57 items and 11 factors. Data-driven explorative adjustments were made to improve model fit. Based on this model an instrument was developed with three scales ("Reflective Wellbeing", "Affective Wellbeing" and "Perceived Access to Options") totaling 15 items. This instrument showed adequate psychometric characteristics in terms of reliability and fit index values. This study shows how the concept of option freedom can be operationalized for health-related wellbeing assessment. Furthermore, the analysis indicates that in the context of outcome measurement, information about both capabilities and functionings related to subjective wellbeing is required to assess the overall wellbeing of an individual. Further research is needed to validate the instrument.