If it's information, it's not "bias": a scoping review and proposed nomenclature for future response-shift research

The growth in response-shift methods has enabled a stronger empirical foundation to investigate response-shift phenomena in quality-of-life (QOL) research; but many of these methods utilize certain language in framing the research question(s) and interpreting results that treats response-shift effects as "bias," "noise," "nuisance," or otherwise warranting removal from the results rather than as information that matters. The present project will describe the various ways in which researchers have framed the questions for investigating response-shift issues and interpreted the findings, and will develop a nomenclature for such that highlights the important information about resilience reflected by response-shift findings.

A scoping review was done of the QOL and response-shift literature (n = 1100 articles) from 1963 to 2020. After culling only empirical response-shift articles, raters characterized how investigators framed and interpreted study research questions (n = 164 articles).

Of 10 methods used, papers using four of them utilized terms like "bias" and aimed to remove response-shift effects to reveal "true change." Yet, the investigators' reflections on their own conclusions suggested that they do not truly believe that response shift is error to be removed. A structured nomenclature is proposed for discussing response-shift results in a range of research contexts and response-shift detection methods.

It is time for a concerted and focused effort to change the nomenclature of those methods that demonstrated this misinterpretation. Only by framing and interpreting response shift as information, not bias, can we improve our understanding and methods to help to distill outcomes with and without response-shift effects.