Veränderungsmessung mit der Hospital Anxiety and Depression Scale (HADS): Änderungssensitivität und Änderungsreliabilität

! Responsiveness or sensitivity to change of a questionnaire is an important criterion in the as− sessment of the effect of a medical intervention. In the literature there are several criteria for re− sponsiveness, based on changes in the popula− tion mean. Here we present an alternative ap− proach for the measurement of change (change reliability), applying the criteria of internal con− sistency to change scores. Using the Hospital Anxiety and Depression Scale HADS, these ap− proaches are demonstrated and compared for 2 subject samples, comprising 901 oncologic pa− tients and 2695 cardiac patients. The effect size d is well suited to assess the effect of an interven− tion, based on changes of the sample mean. The analyses of the 2 samples yielded effect sizes of about 0.25. The newly created change reliability yielded coefficients of about .70 which indicate the reliability of the individual changes in anxie− ty and depression.