An evaluation of a psychosocial intervention for survivors of childhood cancer: Paradoxical effects of response shift over time

This study examined the impact of response shift on a psychosocial treatmen t evaluation of 22 young adult cancer survivors. An age-matched cohort of 5 4 healthy controls were included in the study to provide a comparison for n ormative levels and structure of quality-of-life (QOL). It was found that t his evaluation of a psychosocial intervention for young adult cancer surviv ors was notably influenced by response shift phenomenon. Standard analyses suggested that the intervention had no impact on measured aspects of well-b eing. It did appear to yield an immediate gain in reported global QOL, but seemed to cause a significant decline over time. By considering response sh ift, it was highlighted that an apparently deleterious effect on QOL was la rgely a function of response shift. This response shift effect was reflecte d not only in changes in internal standards, but also in values and in conc eptualization of QOL. The intervention seemed to have normalized survivors' conceptualization of QOL so that it was increasingly similar to their age- matched cohort. Future psychosocial intervention research should explicitly consider response shift in a randomized treatment evaluation. Copyright (C ) 1999 John Wiley & Sons, Ltd.