Confirmatory factor analyses of the ORTO 15-, 11- and 9-item scales and recommendations for suggested cut-off scores.

Abstract

To explore the validity and recommend cut-off scores in an English-speaking sample for 9, 11, and 15-item versions of the ORTO measure for orthorexia, a proposed eating disorder characterised by a pathological obsession with consuming only 'healthy' foods. The sample comprised of 585 participants (82.4% female) who completed an online questionnaire containing the ORTO-15, Eating Attitudes test, Obsessive Compulsive Inventory Revised. A series of Confirmatory Factor Analyses were conducted to test model fit. Binary logistic linear regression and receiver-operating-characteristics (ROC) analyses were used to obtain cut-offs. Results showed that none of the three published versions (9, 11, and 15-item) of the ORTO produced an acceptable model. Subsequent exploratory and confirmatory factor analyses yielded a seven-item version of the ORTO (ORTO-7) with a strong and stable factor structure. Analysis of cut-offs revealed that a cut-off score of equal or greater than 19 on the ORTO-7 represents probable orthorexia. Level V, descriptive study.