Psychometric Properties of a New Measure for Orthorexia Nervosa: The Orthorexia Nervosa Scale (ONS)
Term of Award
Doctor of Psychology in Clinical Psychology (Psy.D.)
Document Type and Release Option
Dissertation (open access)
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution 4.0 License.
Department of Psychology
Committee Member 1
Committee Member 2
Orthorexia nervosa (ON) is a disordered eating pattern that has recently attracted attention from researchers and clinicians, and can lead to some of the same negative effects as other recognized eating disorders, including malnutrition. To continue exploring unique symptoms and features of this disorder, a new scientifically rigorous and inclusive measure needs to be created, focusing on a sample of individuals in the United States. The purpose of this dissertation was to create a valid measure for ON symptomology using rigorous statistical procedures with samples of United States adults. The first study determined the factor structure of the items though an exploratory factor analysis, which yielded a two-factor solution: Behavioral Dysfunction and Social Dysfunction. The two factors demonstrated high internal consistency scores. The second study was conducted to confirm the two-factor solution. While the two-factor solution discovered was only a fair fit, it generated better indices of fit compared to a one-factor solution. The final study evaluated the factor structure for a second time, and also investigated temporal stability of the items while exploring convergent, discriminant, and predictive validity of the two ON factor scores. Consistent with the second study, results confirmed a fair fit of the two-factor solution. Results indicated good temporal consistency scores over a three-month time interval. Finally, the measure displayed convergent validity with measures of perfectionism, obsessions and compulsions, and body image dissatisfaction. Overall, this measure is a good starting point for creating a more scientifically rigorous and inclusive measure of ON for a US population.
Conrad, Rebecca, "Psychometric Properties of a New Measure for Orthorexia Nervosa: The Orthorexia Nervosa Scale (ONS)" (2019). Electronic Theses and Dissertations. 1877.
Research Data and Supplementary Material