The psychometric properties of Orthorexia Nervosa assessment scales: A systematic review and reliability generalization.

The main objective of this systematic review was to provide a comprehensive overview of the psychometric properties of all available Orthorexia Nervosa (ON) assessment tools, in order to evaluate their scope of application for research and practice. Ten databases were searched for studies quantitatively assessing ON. The psychometric properties were evaluated according to specified quality criteria, focusing on the reliability, structural validity and construct validity of the scales. A meta-analytic approach was used to summarize eligible Cronbach's alpha coefficients between studies. Sixty-eight unique studies fulfilled the inclusion criteria for this systematic review. Ten discrete ON scales were identified. Half of the included studies exclusively utilized a version of the ORTO-15. The evaluation of all available ON measures raise issues regarding ON's dimensionality and conceptualization. Most of the identified scales require further validation. Based on the reported psychometric properties it is advised to re-evaluate existing tools and to focus on establishing consensus regarding the conceptualization of ON to establish a measure with sound psychometric properties.