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Original Article

Differential Item Functioning in Brief Instruments of Disordered Eating

Published Online:https://doi.org/10.1027/1015-5759/a000472

Abstract. Most instruments for the assessment of disordered eating were developed and validated in young female samples. However, they are often used in heterogeneous general population samples. Therefore, brief instruments of disordered eating should assess the severity of disordered eating equally well between individuals with different gender, age, body mass index (BMI), and socioeconomic status (SES). Differential item functioning (DIF) of two brief instruments of disordered eating (SCOFF, Eating Attitudes Test [EAT-8]) was modeled in a representative sample of the German population (N = 2,527) using a multigroup item response theory (IRT) and a multiple-indicator multiple-cause (MIMIC) structural equation model (SEM) approach. No DIF by age was found in both questionnaires. Three items of the EAT-8 showed DIF across gender, indicating that females are more likely to agree than males, given the same severity of disordered eating. One item of the EAT-8 revealed slight DIF by BMI. DIF with respect to the SCOFF seemed to be negligible. Both questionnaires are equally fair across people with different age and SES. The DIF by gender that we found with respect to the EAT-8 as screening instrument may be also reflected in the use of different cutoff values for men and women. In general, both brief instruments assessing disordered eating revealed their strengths and limitations concerning test fairness for different groups.

References

  • Bauer, S., Winn, S., Schmidt, U., & Kordy, H. (2005). Construction, scoring and validation of the Short Evaluation of Eating Disorders (SEED). European Eating Disorders Review, 13, 191–200. https://doi.org/10.1002/erv.637 First citation in articleCrossrefGoogle Scholar

  • Benjamini, Y., & Hochberg, Y. (1995). Controlling the false discovery rate: a practical and powerful approach to multiple testing. Journal of the Royal Statistical Society. Series B (Methodological), 57, 289–300. First citation in articleCrossrefGoogle Scholar

  • Berger, U., Wick, K., Hölling, H., Schlack, R., Bormann, B., Brix, C., … Strauss, B. (2011). Screening riskanten Essverhaltens bei 12-jährigen Mädchen und Jungen: Psychometrischer Vergleich der deutschsprachigen Versionen von SCOFF und EAT-26 [Screening of disordered eating in 12-year-old girls and boys: Psychometric analysis of the German versions of SCOFF and EAT-26]. Psychotherapie Psychosomatik Medizinische Psychologie, 61, 311–318. https://doi.org/10.1055/s-0031-1271786 First citation in articleCrossrefGoogle Scholar

  • Botella, J., Sepulveda, A. R., Huang, H., & Gambara, H. (2013). A meta-analysis of the diagnostic accuracy of the SCOFF. Spanish Journal of Psychology, 16, E92. https://doi.org/10.1017/sjp.2013.92 First citation in articleCrossrefGoogle Scholar

  • Cavanagh, A., Wilson, C. J., Caputi, P., & Kavanagh, D. J. (2016). Symptom endorsement in men versus women with a diagnosis of depression: A differential item functioning approach. International Journal of Social Psychiatry, 62, 549–559. https://doi.org/10.1177/0020764016653980 First citation in articleCrossrefGoogle Scholar

  • Garfinkel, P., & Newman, A. (2001). The Eating Attitudes Test: Twenty-five years later. Eating and Weight Disorders, 6, 1–21. https://doi.org/10.1007/BF03339747 First citation in articleCrossrefGoogle Scholar

  • Garner, D. M., & Garfinkel, P. E. (1979). The Eating Attitudes Test: An index of the symptoms of anorexia nervosa. Psychological Medicine, 9, 273–279. First citation in articleCrossrefGoogle Scholar

  • Garner, D. M., Olmstedt, M. P., Bohr, Y., & Garfinkel, P. E. (1982). The Eating Attitudes Test: Psychometric features and clinical correlates. Psychological Medicine, 12, 871–878. First citation in articleCrossrefGoogle Scholar

  • Herpertz-Dahlmann, B., Wille, N., Hölling, H., Vloet, T. D., & Ravens-Sieberer, U. (2008). Disordered eating behaviour and attitudes, associated psychopathology and health-related quality of life: Results of the BELLA study. European Child and Adolescent Psychiatry, 17(Suppl 1), 82–91. https://doi.org/10.1007/s00787-008-1009-9 First citation in articleCrossrefGoogle Scholar

  • Hilbert, A., de Zwaan, M., & Braehler, E. (2012). How frequent are eating disturbances in the population? Norms of the eating disorder examination-questionnaire. PLoS One, 7, e29125. https://doi.org/10.1371/journal.pone.0029125 First citation in articleCrossrefGoogle Scholar

  • Hölling, H., & Schlack, R. (2007). Essstörungen im Kindes- und Jugendalter. Erste Ergebnisse aus dem Kinder- und Jugendgesundheitssurvey (KiGGS) [Eating disorders in children and adolescents. First results of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS)]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz, 50, 794–799. https://doi.org/10.1007/s00103-007-0242-6 First citation in articleCrossrefGoogle Scholar

  • Jacobi, F., Höfler, M., Strehle, J., Mack, S., Gerschler, A., Scholl, L., … Wittchen, H. U. (2014). Psychische Störungen in der Allgemeinbevölkerung: Studie zur Gesundheit Erwachsener in Deutschland und ihr Zusatzmodul Psychische Gesundheit (DEGS1-MH) [Mental disorders in general population: Study on the health of adults in Germany and the additional module mental health (DEGS1-MH)]. Nervenarzt, 85, 77–87. https://doi.org/10.1007/s00115-013-3961-y First citation in articleCrossrefGoogle Scholar

  • Kemper, C. J., Brähler, E., & Zenger, M. (2014). Psychologische und sozialwissenschaftliche Kurzskalen: Standardisierte Erhebungsinstrumente für Wissenschaft und Praxis [Short scales in psychology and social science: Standardized survey instruments for science and practice]. Berlin, Germany: MWV Medizinisch Wissenschaftliche Verlagsgesellschaft mbH & Co KG. First citation in articleGoogle Scholar

  • Killen, J. D., Taylor, C. B., Hayward, C., Wilson, D. M., Haydel, K. F., Hammer, L. D., … Kraemer, H. (1994). Pursuit of thinness and onset of eating disorder symptoms in a community sample of adolescent girls: A three-year prospective analysis. International Journal of Eating Disorders, 16, 227–238. First citation in articleCrossrefGoogle Scholar

  • Kliem, S., Mössle, T., Zenger, M., Strauss, B., Brahler, E., & Hilbert, A. (2016). The eating disorder examination-questionnaire 8: A brief measure of eating disorder psychopathology (EDE-Q8). International Journal of Eating Disorders, 49, 613–616. https://doi.org/10.1002/eat.22487 First citation in articleCrossrefGoogle Scholar

  • Kliem, S., Schmidt, R., Vogel, M., Hiemisch, A., Kiess, W., & Hilbert, A. (2017). An 8-item short form of the Eating Disorder Examination-Questionnaire adapted for children (ChEDE-Q8). International Journal of Eating Disorders, 50, 679–686. https://doi.org/10.1002/eat.22658 First citation in articleCrossrefGoogle Scholar

  • Klump, K. L., Bulik, C. M., Kaye, W. H., Treasure, J., & Tyson, E. (2009). Academy for eating disorders position paper: Eating disorders are serious mental illnesses. International Journal of Eating Disorders, 42, 97–103. https://doi.org/10.1002/eat.20589 First citation in articleCrossrefGoogle Scholar

  • Kromeyer-Hauschild, K., Wabitsch, M., Kunze, D., Geller, F., Geiß, H. C., Hesse, V., … Hebebrand, J. (2001). Perzentile für den Body-mass-Index für das Kindes- und Jugendalter unter Heranziehung verschiedener deutscher Stichproben [Percentiles of body mass index in children and adolescents evaluated from different regional German studies]. Monatsschrift Kinderheilkunde, 149, 807–818. https://doi.org/10.1007/s001120170107 First citation in articleCrossrefGoogle Scholar

  • Kruyen, P. M., Emons, W. H. M., & Sijtsma, K. (2013). On the shortcomings of shortened tests: A literature review. International Journal of Testing, 13, 223–248. https://doi.org/10.1080/15305058.2012.703734 First citation in articleCrossrefGoogle Scholar

  • Mellenbergh, G. J. (1989). Item bias and item response theory. International Journal of Educational Research, 13, 127–143. First citation in articleCrossrefGoogle Scholar

  • Meulders, M., & Xie, Y. (2004). Person-by-item predictors. In P. De BoeckM. WilsonEds., Explanatory item response models: A generalized linear and nonlinear approach (Vol. 1, pp. 213–240). New York, NY: Springer Science + Business Media New York. First citation in articleGoogle Scholar

  • Mond, J. M., Myers, T. C., Crosby, R. D., Hay, P. J., Rodgers, B., Morgan, J. F., … Mitchell, J. E. (2008). Screening for eating disorders in primary care: EDE-Q versus SCOFF. Behaviour Research and Therapy, 46, 612–622. https://doi.org/10.1016/j.brat.2008.02.003 First citation in articleCrossrefGoogle Scholar

  • Morgan, J. F., Reid, F., & Lacey, J. H. (1999). The SCOFF questionnaire: Assessment of a new screening tool for eating disorders. British Medical Journal, 319, 1467–1468. First citation in articleCrossrefGoogle Scholar

  • Muthén, L. K., & Muthén, B. O. (1998–2010). Mplus user’s guide (6th ed.). Los Angeles, CA: Muthén & Muthén. First citation in articleGoogle Scholar

  • Myers, T. A. (2011). Goodbye, listwise deletion: Presenting hot deck imputation as an easy and effective tool for handling missing data. Communication Methods and Measures, 5, 297–310. https://doi.org/10.1080/19312458.2011.624490 First citation in articleCrossrefGoogle Scholar

  • Reilly, E. E., Anderson, L. M., Schaumberg, K., & Anderson, D. A. (2014). Gender-based differential item functioning in common measures of body dissatisfaction. Body Image, 11, 206–209. https://doi.org/10.1016/j.bodyim.2014.02.001 First citation in articleCrossrefGoogle Scholar

  • Richter, F., Brähler, E., Strauss, B., & Berger, U. (2014). Factoranalytic Structure of a Short Version of the Eating Attitudes Test (EAT-13) and prevalences of disordered eating in a representative German sample. Psychotherapie Psychosomatik Medizinische Psychologie, 64, 465–471. https://doi.org/10.1055/s-0034-1394461 First citation in articleCrossrefGoogle Scholar

  • Richter, F., Strauss, B., Brähler, E., Adametz, L., & Berger, U. (2017). Screening disordered eating in a representative sample of the German population: Usefulness and psychometric properties of the German SCOFF questionnaire. Eating Behaviors, 25, 81–88. https://doi.org/10.1016/j.eatbeh.2016.06.022 First citation in articleCrossrefGoogle Scholar

  • Richter, F., Strauss, B., Brähler, E., Altmann, U., & Berger, U. (2016). Psychometric properties of a short version of the Eating Attitudes Test (EAT-8) in a German representative sample. Eating Behaviors, 21, 198–204. https://doi.org/10.1016/j.eatbeh.2016.03.006 First citation in articleCrossrefGoogle Scholar

  • Rohde, P., Stice, E., & Marti, C. N. (2015). Development and predictive effects of eating disorder risk factors during adolescence: Implications for prevention efforts. International Journal of Eating Disorders, 48, 187–198. https://doi.org/10.1002/Eat.22270 First citation in articleCrossrefGoogle Scholar

  • Samnaliev, M., Noh, H. L., Sonneville, K. R., & Austin, S. B. (2015). The economic burden of eating disorders and related mental health comorbidities: An exploratory analysis using the U.S. Medical Expenditures Panel Survey. Preventive Medicine Reports, 2, 32–34. https://doi.org/10.1016/j.pmedr.2014.12.002 First citation in articleCrossrefGoogle Scholar

  • Sheppard, R., Han, K., Colarelli, S. M., Dai, G., & King, D. W. (2006). Differential item functioning by sex and race in the Hogan Personality Inventory. Assessment, 13, 442–453. https://doi.org/10.1177/1073191106289031 First citation in articleCrossrefGoogle Scholar

  • Siervo, M., Boschi, V., Papa, A., Bellini, O., & Falconi, C. (2005). Application of the SCOFF, Eating Attitude Test 26 (EAT 26) and Eating Inventory (TFEQ) Questionnaires in young women seeking diet-therapy. Eating and Weight Disorders, 10, 76–82. First citation in articleCrossrefGoogle Scholar

  • Slof-Op ‘t Landt, M. C. T., van Furth, E. F., Rebollo-Mesa, I., Bartels, M., van Beijsterveldt, C. E. M., Slagboom, P. E., … Dolan, C. V. (2009). Sex differences in sum scores may be hard to interpret: The importance of measurement invariance. Assessment, 16, 415–423. https://doi.org/10.1177/1073191109344827 First citation in articleCrossrefGoogle Scholar

  • Smith, G. T., McCarthy, D. M., & Anderson, K. G. (2000). On the sins of short-form development. Psychological Assessment, 12, 102–111. First citation in articleCrossrefGoogle Scholar

  • Snoek, H. M., van Strien, T., Janssens, J. M. A. M., & Engels, R. C. M. E. (2008). Restrained eating and BMI: A longitudinal study among adolescents. Health Psychology, 27, 753–759. https://doi.org/10.1037/0278-6133.27.6.753 First citation in articleCrossrefGoogle Scholar

  • Solmi, F., Hatch, S. L., Hotopf, M., Treasure, J., & Micali, N. (2014). Prevalence and correlates of disordered eating in a general population sample: the South East London Community Health (SELCoH) study. Social Psychiatry and Psychiatric Epidemiology, . https://doi.org/10.1007/s00127–014-0822–3 First citation in articleCrossrefGoogle Scholar

  • Solmi, F., Hatch, S. L., Hotopf, M., Treasure, J., & Micali, N. (2015). Validation of the SCOFF questionnaire for eating disorders in a multiethnic general population sample. International Journal of Eating Disorders, 48, 312–316. https://doi.org/10.1002/eat.22373 First citation in articleCrossrefGoogle Scholar

  • Spillane, N. S., Boerner, L. M., Anderson, K. G., & Smith, G. T. (2004). Comparability of the Eating Disorder Inventory-2 between women and men. Assessment, 11, 85–93. https://doi.org/10.1177/1073191103260623 First citation in articleCrossrefGoogle Scholar

  • Stice, E. (2002). Risk and maintenance factors for eating pathology: A meta-analytic review. Psychological Bulletin, 128, 825–848. https://doi.org/10.1037/0033-2909.128.5.825 First citation in articleCrossrefGoogle Scholar

  • Striegel-Moore, R. H., DeBar, L., Wilson, G. T., Dickerson, J., Rosselli, F., Perrin, N., … Kraemer, H. C. (2008). Health services use in eating disorders. Psychological Medicine, 38, 1465–1474. https://doi.org/10.1017/s0033291707001833 First citation in articleCrossrefGoogle Scholar

  • Striegel-Moore, R. H., Rosselli, F., Perrin, N., DeBar, L., Wilson, G. T., May, A., & Kraemer, H. C. (2009). Gender difference in the prevalence of eating disorder symptoms. International Journal of Eating Disorders, 42, 471–474. https://doi.org/10.1002/eat.v42:510.1002/eat.20625 First citation in articleCrossrefGoogle Scholar

  • Strother, E., Lemberg, R., Stanford, S. C., & Turberville, D. (2012). Eating disorders in men: Underdiagnosed, undertreated, and misunderstood. Eating Disorders, 20, 346–355. https://doi.org/10.1080/10640266.2012.715512 First citation in articleCrossrefGoogle Scholar

  • Stuhldreher, N., Wild, B., König, H. H., Konnopka, A., Zipfel, S., & Herzog, W. (2015). Determinants of direct and indirect costs in anorexia nervosa. International Journal of Eating Disorders, 48, 139–146. https://doi.org/10.1002/eat.22274 First citation in articleCrossrefGoogle Scholar

  • Teresi, J. A., Ramirez, M., Lai, J.-S., & Silver, S. (2008). Occurrences and sources of Differential Item Functioning (DIF) in patient-reported outcome measures: Description of DIF methods, and review of measures of depression, quality of life and general health. Psychology Science Quarterly, 50, 538. First citation in articleGoogle Scholar

  • Thielemann, D., Sengewald, M.-A., Kappler, G., & Steyer, R. (2017). A probit latent state IRT model with latent item-effect variables. European Journal of Psychological Assessment, 33, 271–284. First citation in articleLinkGoogle Scholar

  • Tritt, K., von Heymann, F., Zaudig, M., Zacharias, I., Söllner, W., & Loew, T. (2008). Entwicklung des Fragebogens “ICD-10-Symptom-Rating” (ISR) [Development of the “ICD-10-Symptom-Rating” (ISR) questionnaire]. Zeitschrift für Psychosomatische Medizin und Psychotherapie, 54, 420–429. First citation in articleGoogle Scholar

  • WHO. (1995). Physical status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. WHO Technical Report Series 854. Geneva, Switzerland: World Health Organization. First citation in articleGoogle Scholar

  • Woods, C. M. (2009a). Empirical selection of anchors for tests of differential item functioning. Applied Psychological Measurement, 33, 42–57. First citation in articleCrossrefGoogle Scholar

  • Woods, C. M. (2009b). Evaluation of MIMIC-model methods for DIF Testing with comparison to two-group analysis. Multivariate Behavioral Research, 44, 1–27. https://doi.org/10.1080/00273170802620121 First citation in articleCrossrefGoogle Scholar

  • Zeiler, M., Waldherr, K., Philipp, J., Nitsch, M., Dur, W., Karwautz, A., & Wagner, G. (2016). Prevalence of eating disorder risk and associations with health-related quality of life: Results from a large school-based population screening. European Eating Disorders Review, 24, 9–18. https://doi.org/10.1002/erv.2368 First citation in articleCrossrefGoogle Scholar

  • Zumbo, B. D. (1999). A handbook on the theory and methods of differential item functioning (DIF): Logistic regression modeling as a unitary framework for binary and Likert-type (ordinal) item scores. Ottawa, ON: Directorate of Human Resources Research and Evaluation, Department of National Defense. First citation in articleGoogle Scholar