Prospective vs retrospective assessment of lower urinary tract symptoms in patients with advanced prostate cancer: the effect of ‘response shift’

Abstract

These results question the assumption that contemporaneously collected pre-test scores are interchangeable with retrospectively assessed then-tests. This suggests that caution is required when comparing the results of studies that use these two alternative techniques of data collection. The difference between then-test and pre-test scores may represent an example of a phenomenon termed 'response shift', in which, by adapting to their disease, patients changed the internal standards by which they assessed their symptoms.