Philosophical Perspectives on Response Shift

Purpose: This paper brings a philosophical perspective to response shift research with the aim of raising new critical questions, clarifying some of the concepts employed, and providing a philosophical context within which to critically examine the assumptions that shape the field.

Methods: This critical analysis aims to reveal assumptions and clarify concepts and/or definitions that undergird methodological practice and theory.

Results: We bring attention to the distinction of weak and strong evaluations, and the implications and consequences for construct validity and for designing patient-reported outcome measures (PROMs). We then consider the epistemology of PROMs, suggesting that they are better suited to a social constructivist approach than a scientific realist one. Finally, we examine the relationship between disability and response shift, arguing that in at least some cases, response shifts should not be understood as 'measurement bias'.

Conclusion: Our analysis reveals various concerns and further questions related to the role that substantive values play in the assessment of QoL. It also draws response shift into a wider arena, with broader issues of interpretation, self-evaluation, the meaning of the 'good life', and the status and legitimacy we accord to various scientific methods.