%0 Case Reports %T A case of validity evidence for the Interprofessional Attitudes Scale. %A Violato E %A King S %J J Interprof Care %V 35 %N 4 %D Jul-Aug 2021 %M 32667236 %F 2.663 %R 10.1080/13561820.2020.1786359 %X Numerous measures have been developed for the assessment of interprofessional attitudes, including the Interprofessional Attitudes Scale (IPAS). The purpose of this study was to assess, and contribute to, the validity evidence for the IPAS. The IPAS was used in a three-year longitudinal study to collect data from first year health professionals. Three forms of assessment were conducted to accrue validity evidence for the IPAS: Exploratory Factor Analysis, Item Analysis, and analysis using Item Response Theory. Data was collected from 337 participants over three years. Separately, and cumulatively, the Exploratory Factor Analysis, Item Analysis and analysis using Item Response Theory identified issues with the content, response process, internal structure, and consequential validity of the IPAS. The outcomes of the present study call into question the use of the IPAS, and other measures, for the assessment of interprofessional attitudes. The present study contributes several pieces of evidence to the validity of the IPAS and the reevaluation of the use of attitude assessment in interprofessional education.