Psychometric properties of the Chinese version of the Düsseldorf Orthorexia Scale: prevalence and demographic correlates of orthorexia nervosa among Chinese university students.

PURPOSE: As there is no measure available in Chinese for assessing orthorexia nervosa (ON), and as the Düsseldorf Orthorexia Scale (DOS) has demonstrated to be a valid measure for such a purpose, the current study aimed to obtain a Chinese version of the DOS (C-DOS), to evaluate psychometric properties of the C-DOS in a sample of Chinese university students, and to explore the prevalence of ON among the participants. METHODS: According to standard procedures, the C-DOS was obtained and administered to 1075 mainland Chinese university students (52.7% female) recruited from two provinces in mainland China. To examine the factor structure of the C-DOS, the total sample was split into two halves, one for exploratory factor analysis, and the other for confirmatory factor analysis. The ordinal alpha and test-retest reliability were examined. Convergent and divergent validity was assessed by conducting Pearson correlation analyses between the C-DOS and other theoretically related/unrelated measures. Prevalence of ON was estimated based on the total score of the C-DOS with the cutoff value of 30. RESULTS: A three-factor structure was revealed for the C-DOS. The C-DOS showed good internal consistency with an ordinal alpha of 0.80, and it also had good test-retest reliability of 0.77. The total scores of the C-DOS had strong and statistically significant positive correlations with eating inflexibility, while the total scores had weak correlations with other eating disturbances. Strong measurement invariance across gender groups was also supported. The prevalence of ON was 7.8% with males showing higher rates of ON than females (10.6% vs. 5.3%). CONCLUSIONS: The Chinese version of the DOS (C-DOS) was psychometrically adequate for the sample of Chinese students. Given the high prevalence of ON found in the current study, more attention to ON, as well as further research and potential interventions, are warranted in China. LEVEL OF EVIDENCE: Descriptive (cross-sectional) study, Level V.