Assessing subjective change in chronic illness: An examination of response shift in health-related and goal-oriented subjective status
Yardley L., Dibb B.
This study examined changes over time on scales from the Short Form 36 (SF-36) and a new measure of goal-oriented subjective status (the GOSS) which assessed perceived rate of goal approach. Our aim was to determine whether adaptation to a moderately disabling chronic illness was associated with response shift. We also investigated predictors of response shift. At baseline, 301 members of a self-help group for people with Mnire's disease completed the GOSS and SF-36 scales, and potential predictors of response shift. At 10-month follow-up, respondents completed the GOSS and SF-36 again in the conventional manner, and as a Then-test. The GOSS was the only scale that indicated subjective improvement between baseline and follow-up. Then-test results suggested substantial response shift on the SF-36. Severe symptoms and social comparison predicted greater response shift. Less response shift was seen in those with a longer time since diagnosis, longer membership of the self-help group and higher baseline levels of self-esteem and optimism.