The Effect of Item Observability, Clarity and Wording on Patient/Nurse Ratings when using the ASA Scale

Abstract
Many studies show discrepancies between patients' and professionals' ratings on the same questionnaire regarding the patient's health. A relevant question is whether the differences in ratings reflect real differences between patients and professionals or whether they are caused by characteristics of the instrument. In this study, we address the latter option by examining the effects of 3 item characteristics (item wording, observability and clarity) on the degree of patient/nurse discrepancies in ratings of the items of the Appraisal of Self‐care Agency (ASA) scale. Secondary analysis on 252 patient/nurse ratings showed that item wording (positively and negatively formulated items), and the observability of the items have a significant effect on the mean absolute difference score. No effect was found for clarity. These results were generally confirmed by subgroup analyses.