Eating Disorder Diagnostic Scale (EDDS)

Abstract

The Eating Disorder Diagnostic Scale (EDDS) is a concise, 22-item self-report questionnaire developed by Stice, Telch, and Rizvi (2000). Its primary function is to assess the symptomatology of three core eating disorders: Anorexia nervosa, Bulimia nervosa, and Binge-eating disorder. The scale is structured to closely map onto the diagnostic criteria outlined in the DSM-IV, providing both diagnostic information via a categorical scale and a continuous measure of disordered eating pathology via a symptom composite scale.

Keywords

Eating Disorder Diagnostic Scale, EDDS, Anorexia nervosa, Bulimia nervosa, Binge-eating disorder, DSM-IV, Self-report, Psychological assessment, Eating pathology, Screening tool.

Authors

Eric Stice, Christina F. Telch, Shireen L. Rizvi

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Purpose

The primary purpose of the EDDS is to provide a brief, efficient, and psychometrically sound measure for the assessment of core eating disorder symptomatology, specifically Anorexia nervosa, Bulimia nervosa, and Binge-eating disorder. It was explicitly designed to reflect the diagnostic criteria established by the DSM-IV at the time of its development.

Beyond its use as a diagnostic aid, the EDDS serves multiple clinical functions due to its sensitivity to change over time. It is highly versatile, applicable as an initial screening tool in non-clinical settings, a supportive instrument for clinical diagnosis, and a measure for monitoring treatment progress and evaluating outcomes.

Construct

The EDDS measures the psychological construct of disordered eating pathology, encompassing the specific cognitive, attitudinal, and behavioral symptoms characteristic of major eating disorders. The scale is divided conceptually into components that map directly to diagnostic criteria, such as body image disturbance, frequency of objective binge eating, and compensatory behaviors.

The instrument yields two distinct types of scores reflecting different facets of the construct. The diagnostic scale provides categorical outcomes, using a scoring algorithm developed by Stice et al. (2000) to determine cut-offs that inform potential clinical diagnosis. Conversely, the symptom composite scale generates a continuous score that reflects the overall severity of disordered eating behaviors and attitudes, allowing for dimensional measurement of pathology.

Validity

Validation studies confirm the strong psychometric properties of the EDDS. Content validity was established through a rigorous process involving a panel of 14 leading eating disorder experts who reviewed the item pool to ensure adequate reflection of the DSM-IV diagnostic criteria for Anorexia nervosa, Bulimia nervosa, and Binge-eating disorder.

Furthermore, the EDDS demonstrated robust convergent validity. Data showed significantly higher symptom composite scores among participants with clinically diagnosed eating disorders compared to non-diagnosis control counterparts. This differentiation confirms that the instrument successfully measures the intended construct by distinguishing between clinical and non-clinical populations.

Reliability

The reliability of the EDDS was assessed using both test-retest stability and internal consistency measures. The results demonstrated strong stability over a one-week period. Specifically, 1-week test-retest reliability coefficients, measured using kappa coefficients, were excellent for Anorexia nervosa (kappa = .95). Coefficients were deemed adequate for Bulimia nervosa (kappa = .71) and Binge-eating disorder (kappa = .75). The overall symptom composite score also exhibited strong stability (kappa = .87).

Internal consistency of the overall symptom composite score was also robust, yielding a Cronbach’s α of .91. According to Shrout’s (1998) widely accepted psychometric rule-of-thumb, kappa values above .8 indicate high reliability, supporting the reliable use of the EDDS across its primary diagnostic applications.

Factor Analysis

While the original validation paper (Stice et al., 2000) focused on validating items against established DSM-IV diagnostic criteria, the underlying structure of the EDDS is implicitly multi-factorial, reflecting the separate yet related constructs of Anorexia nervosa, Bulimia nervosa, and Binge-eating disorder. The 22 items are designed to load onto behavioral and attitudinal domains relevant to these distinct clinical syndromes.

The scoring methodology supports a structural approach based on symptom clusters: items relating to restrictive attitudes, binge frequency, and compensatory behaviors (such as purging or excessive exercise) are grouped to generate the specific sub-diagnoses and the continuous symptom composite score. Later research has generally supported its utility in measuring a unitary disordered eating construct alongside specific diagnostic categories.

Instrument

Test Type: Self-report questionnaire, Screening tool, Diagnostic aid

Format: 22 items, utilizing a combination of Likert ratings, dichotomous scores (Yes/No), behavioral frequency scores, and specific open-ended questions (e.g., height/weight).

Language Available: English (Validated versions exist in other languages, e.g., Chinese, referenced in Lee et al., 2007).

Population Group: Clinical and non-clinical populations being screened for eating disorders.

Age Group: Adolescents and Adults (Initially validated on females aged 13 to 65 years).

Population Details: The initial validation sample consisted of American females, aged 13 to 65 years, including individuals with and without diagnosed eating disorders. Subsequent studies, however, have highlighted potential limitations regarding gender and cultural invariance.

Test Methodology: Administration is typically quick, requiring only a few minutes to complete. The scale assesses symptoms over specific time frames, such as the past 3 months (attitudinal symptoms and Bulimia frequency) and the past 6 months (Binge-eating disorder frequency).

Keywords

Psychometric, Test-retest reliability, Internal consistency, Cronbach’s α, Kappa coefficient, Convergent validity, Screening, Treatment monitoring, Eating pathology.

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Authors

Author ORCID Identifier: Not provided in source.

Affiliation Email addresses: Not provided in source.

Correspondence Address: Not provided in source.

Permissions & Fee and Test Year

The EDDS was developed and validated in 2000 (Stice, Telch, & Rizvi). The scale is highly accessible and is freely available for research and clinical use. The original PDF of the scale and scoring information are publicly provided by the authors’ institutions.

Strengths and Limitations

The EDDS is valued for its brevity and efficiency, consisting of only 22 items that allow for rapid completion and scoring. This efficiency enhances its utility in high-volume settings and longitudinal studies. Furthermore, its sensitivity to change makes it an excellent instrument for treatment monitoring and evaluation, tracking symptom reduction over time.

However, the instrument has documented limitations. Studies, such as Lee et al. (2007), have indicated a tendency for the EDDS to generate a high rate of false positives, suggesting a potential weakness in specificity. Yet, given the exceptionally high mortality rate associated with eating disorders compared to other psychiatric conditions, a bias toward sensitivity (identifying potential cases) over specificity is often considered clinically acceptable in initial screening. Additional critical weaknesses include observed gender and cultural insensitivity, as the scale did not adequately capture differing cultural ideals or invariance across diverse ethnic groups, such as Caucasian American and African American women (Kelly et al., 2012).

Access

The Eating Disorder Diagnostic Scale (EDDS) is freely available to researchers and clinicians. The original PDF of the scale can be downloaded here: http://www.ori.org/files/Static%20Page%20Files/EDDS.pdf.

Information regarding the scoring algorithm and interpretation guidelines is also freely accessible. The scoring documentation can be found here: http://www.ori.org/files/Static%20Page%20Files/SticeTelch00.pdf.

References

Arcelus, J., Mitchell, A. J., Wales, J., & Nielsen, S. (2011). Mortality rates in patients with anorexia nervosa and other eating disorders: A meta-analysis of 36 studies. Archives of General Psychiatry, 68(7), 724-731. doi:10.1001/archgenpsychiatry.2011.74

Kelly, N. R., Mitchell, K. S., Gow, R. W., Trace, S. E., Lydecker, J. A., Bair, C. E., & Mazzeo, S. (2012). An evaluation of the reliability and construct validity of eating disorder measures in white and black women. Psychological Assessment, 24(3), 608-617. doi:10.1037/a0026457

Lee, S. W., Stewart, S. M., Striegel-Moore, R. H., Lee, S., Ho, S-Y., Lee, P. W. H., …Lam, T-H. (2007). Validation of the eating disorder diagnostic scale for use with Hong Kong adolescents. International Journal of Eating Disorders, 40(6), 569-574. doi:10.1002/eat

Shrout, P. (1998). Measurement reliability and agreement in psychiatry. Statistical Methods in Medical Research, 7(3), 301-317. doi:10.1191/096228098672090967

Stice, E., Telch, C. F., & Rizvi, S. L. (2000). Development and validation of the eating disorder diagnostic scale: A brief self-report measure of anorexia, bulimia, and binge-eating disorder. Psychological Assessment, 12(2), 123-131. doi:10.1037//1040-3590.12.2.123

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Items of the Eating Disorder Diagnostic Scale (EDDS)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

The EDDS is a 22-item instrument structured to assess specific symptom clusters related to eating disorder diagnoses. The item composition utilizes various response formats, including Likert scales, dichotomous responses, and frequency counts over defined recall periods.

The scale items are grouped thematically as follows:

• The first four questions assess attitudinal symptoms of Anorexia and Bulimia occurring within the past 3 months (e.g., concern over shape and weight).
• The subsequent four items measure the frequency of uncontrollable food consumption, focusing on the number of days per week over the past 6 months (a criterion for Binge-eating disorder) and the number of times per week over the last 3 months (a criterion for Bulimia).
• The following four items measure the frequency of compensatory behaviours (e.g., purging, excessive exercise).
• The final set of questions asks individuals to record objective physical data, including their height and weight, and reproductive status (presence of menstrual cycles and birth control pill use).