Screening for orthorexia nervosa among nursing students: prevalence and associations between the Chinese version of the Düsseldorf Orthorexia Scale and the Chinese version of the Orthorexia Nervosa Inventory

Aim To estimate orthorexia nervosa (ON) screening prevalence and risk stratification among Chinese nursing students, examine associations of sex, grade and BMI with ON screening positivity, and describe symptom severity using the Chinese Orthorexia Nervosa Inventory (C-ONI). Design Cross-sectional survey. Methods Undergraduate nursing students ( n = 693; effective response rate 96.25%) completed the Chinese Düsseldorf Orthorexia Scale (C-DOS) and C-ONI. ON screening positivity was defined as C-DOS ≥30 with three-level risk stratification. Wilson 95% CIs were calculated. Welch's ANOVA compared C-ONI scores across C-DOS strata. Multivariable logistic regression tested correlates (sex, grade, BMI). Agreement between dichotomized C-DOS and ONI (C-ONI ≥72) was examined. Results C-DOS classified 76.0% as ON absent, 10.2% at risk, and 13.7% ON present (95% CI: 11.2%−16.5%). C-ONI total scores increased across strata (42.3 ± 10.2, 58.8 ± 8.7, 70.8 ± 11.9; all p < 0.001). Dichotomized agreement was 90.6% (628/693) with 9.4% discordance (7.9% C-DOS-only; 1.4% ONI-only). Females had lower odds of ON screening positivity than males (OR = 0.423, 95% CI: 0.264–0.678; p < 0.001); BMI and grade were not significant. Conclusions ON screening positivity was 13.7% in Chinese nursing students with a clear risk–severity gradient. Although instruments largely agreed, non-overlap suggests prevalence estimates and individual classification depends on tool/cut-off; validation against clinical anchor criteria is needed.