ORIG I NALRESEARCH

PAPER

Psychometric properties of EDE 12.0Din obese adult patients without bingeeating disorder

E. Mannucci**, V. Ricca*, M. Di Bernardo*, S. Moretti*, P.L. Cabras* and C.M. Rotella***Psychiatric Unit, Department of Neurologic and Psychiatric Sciences, and **Section of Metabolic Diseases,Unit of Endocrinology, Department of Pathophysiology, University of Florence.

ABSTRACT. The aim of the present study is to assess the psychometric properties of theEating Disorder Examination (EDE) 12.0D in obese adult patients without Binge EatingDisorder (BED). A consecutive series of 115 obese patients without BED (23 M; 92 F), seeking treatment for obesity at the Outpatient Clinic of the Section of Metabolic Diseases andDiabetology of the University of Florence was studied using the EDE 12.0D. Patients had amean (±SD) age of 40.8±15.1 years, and a Body Mass Index (BMI) of 36.3±5.9 Kg/m2. Internaconsistency of EDE and its scales was evaluated through Cronbach’s α; factor structure oEDE 12.0D was studied with factor analysis. EDE total and Shape Concern (SC) scores werefound to be higher in females than in males. EDE total, SC and Eating Concern (EC) scoreswere inversely correlated to age, but not BMI. Factor analysis suggested the grouping oitems in two subscales. The first scale includes all the items from EC, Weight Concern (WCand SC except reaction to prescribed weighing; the second scale consists of all the itemsfrom Restraint. Data obtained show that items from EC, WC and SC all converge into thesame factor analysis derived scale in obese patients without BED. EDE 12.0D provides relevant information about psychopathological features of obese patients, but a grouping oitems into subscales different from those originally described could be indicated.(Eating Weight Disord. 2, 144-149, 1997). ©1997, Editrice Kurtis

PSYCHOMETRIC PROPERTIESOF EDE 12.0D IN OBESEADULT PATIENTS WITHOUTBINGE EATING DISORDER

The Eating Disorder Examination (EDE) is asemistructured interview developed in 1987for the assessment of the specific psy-chopathology of eating disorders (1) andthe 12th edition (EDE 12.0D) has been avail-able since 1993 (2). When compared to pre-vious editions, it has been shortened andadapted to provide operational diagnosesaccording to draft criteria of the 4th editionof the Diagnostic and Statistical Manual ofMental Disorders (DSM-IV) (3). Althoughthe DSM-IV requires at least two binge eat-ing episodes per week for three months tomake the diagnosis of bulimia nervosa, theauthors adopted slightly different criteria(at least twelve objective bulimic episodesover the past 3 months, with no more thana 2-week gap between them). Similar crite-

ria have been adopted for Binge EatingDisorder (2).

The original interview consisted of fivesubscales, exploring the major areas of thespecific psychopathology of anorexia nervosa and bulimia nervosa. The subscaleswere labelled Restraint, Bulimia, EatingConcern, Weight Concern and ShapeConcern (4). The assignment of items tosubscales was decided on the basis of theircontent. Four of the original subscalesremain unchanged in the 12th edition of theEDE. The Bulimia subscale has been abolished because it does not provide clinicallyrelevant additional information beyond thawhich can be derived from the frequenciesof binge eating and compensatory behaviors (1). The 12th edition consists of foursubscales (Restraint, Eating ConcernWeight Concern and Shape Concern) plusseveral items that assess the frequency obinge eating and compensatory behaviorsThe global score provides a measure of the

Key words: Obesity, assessment, EatingDisorder Examination,anxiety, depressionCorrespondnce:Prof. Carlo M. Rotella,Sezione di Malattie delMetabolismo e Diabetologia,Unità Operativa diEndocrinologia,Viale Pieraccini 6, 50134 Firenze, Italy.Received: September 15,1997Accepted: January 20, 1998

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EDE 12.0D in obesity

severity of the eating disorder, while thesubscale scores define the psychopatholog-ical profile of individual patients.

This instrument is designed to be admin-istered by specifically trained interviewers.

The validity of EDE has been clearlyestablished with respect to interrater relia-bility (1), and internal consistency (4-5);concurrent (6) and predictive (4-6), validityhave also been studied.

The EDE was devised to overcome someof the limitations of the self-reported mea-sures. A semistructured interview formatwould provide more accurate and detailedinformation on the specific psychopatholo-gy of eating disorders than a self-reportquestionnaire (7). Moreover, self-reportedmeasures are not able to address indetailthe complex concerns about shape andweight that are specific features of anorex-ia nervosa and bulimia nervosa (8). TheEDE has been used in descriptive studies(5, 9-11), and research on treatment (9, 12-14).

Although originally developed forpatients with anorexia nervosa and bulimianervosa, the EDE has also been used inobese patients with binge eating disorder(10, 15, 16); moreover, adaptations havebeen devised for those who are pregnant(17) and subjects with diabetes mellitus (18-20).

The psychometric properties of EDE havenot been described so far in obese patientsnot affected by Binge Eating Disorder. Itshould be observed that, although mostresearch studies have been focused on clin-ical features and treatment of Binge EatingDisorder, a vast majority of obese patientsdo not fulfill the diagnostic criteria for anyformal eating disorder (21). Given the highprevalence of obesity in the general popu-lation in Western countries (22, 23), and itsrelevant impact on health status and qualityof life of affected individuals, the treatmentof obesity is an important medical priority.

It should also be considered that EDEscales were designed on the basis of theircontent, rather than formed following theresults of statistical procedures, i.e. factoranalysis. Factor analysis-derived scales,which are calculated from the actual resultsobtained in patients, should give a moreaccurate description of the psychometricproperties of the test. Moreover, diversitiesin grouping of items in factor analysis-derived scales could give some insight into

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the psychopathological features of differentpatient populations.

The aim of this study is the assessment ofthe psychometric properties of EDE 12.0Din obese patients without BED, in order toidentify psychological and psychopatholog-ical features of obese subjects, possibly dif-ferentiating them from those affected byformal eating disorders.

PATIENTS AND METHODS

A consecutive series of obese outpatientswas studied using a previously validatedItalian translation (24) of the EatingDisorder Examination (EDE) 12.0D (2). Allpatients examined at the Outpatient Clinicof the Section of Metabolic Diseases andDiabetology of the University of Florencebetween September 1, 1996, and December31, 1996, were invited to participate in thestudy, provided they met the followinginclusion criteria:

1. Age between 18 and 65 years;2. Body Mass Index (BMI) > 30 kg/m2;3. absence of formal eating disorders,

including Binge Eating Disorder; mentaldisorder was assessed using the StructuredClinical Interview for DSM-III-R (SCID)(25); DSM-IV criteria were used for thediagnosis of Binge Eating Disorder (3);

4. absence of diabetes mellitus, hypothy-roidism, or any other concurrent medicalcondition known to interfere with bodyweight or eating behavior;

5. absence of concomitant medication(including all kinds of antidepressantdrugs) known to interfere with eating atti-tudes and behavior;

6. illiteracyOf the 118 patients invited, 3 refused to

participate; the final sample consisted of115 patients, (23 M, 92 F), with a mean (±SD) age of 40.8±15.1 years, and a BodyMass Index (BMI) of 36.3±5.9 kg/m2. Ofthose patients, 2 were affected by majordepression, 8 by dysthymia, 4 by adjust-ment disorder with depressed mood, 6 bygeneralized anxiety disorder, according toDSM-III-R criteria. In all patients, eatingattitudes and behavior were investigated bya specifically trained psychiatrist (M.D.B.)using the EDE 12.0D (2).

Statistical analysis of results was per-formed using SPSS for Windows, vs 5.0.2software. Two-sample Student’s t test and

E. Mannucci, V. Ricca, M. Di Bernardo, et al.

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Mann-Whitney U test were used for evalu-ation of differences in numeric variables.Correlations were evaluated with Pearson’sanalysis. The distribution of items into sub-scales was evaluated using factor analysis;this analysis detects similarities in featuresassessed by different questions through theevaluation of the variance of scores of indi-vidual items. Factor analysis was employedto verify if the clustering of items into sub-scales in obese patients without BED wascomparable to that originally proposed bythe authors of EDE for patients withanorexia nervosa and bulimia nervosa (2);principal component analysis with varimaxrotation was employed.

The internal consistency ofthe originalEDE 12.0D scales and of the scales derivedfrom factor analysis was evaluated throughCronbach’s alpha method; internal consis-tency is considered satisfactory forCronbach’s α>0.7.

RESULTS

None of the patient was found to be affect-ed by Binge Eating Disorder, or any otherformal eating disorder.

EDE total and subscale scores are sum-marized in Table 1. Females showed signifi-cantly higher EDE total and “ShapeConcern” scores compared to males. EDEtotal scores showed a significant inversecorrelation with age (r=-0.27, p<0.05). Asignificant inverse correlation of age wasalso observed with “Shape Concern” (r=-0.29, p<0.01) and Eating Concern” (r=-0.28,p<0.05) subscale, but not with “WeightConcern” (r=-0.17, p=NS) and “Restraint”(r=-0.09, p=NS). BMI values did not showany significant correlation with EDE totalscores (r=-0.11, p=NS) or subscale scores(r=-0.14 for “Restraint”, 0.01 for EC, -0.16for WC, and -0.03 for SC; p= NS).Cronbach’s α was 0.71 for “Restraint”, 0.75for EC, 0.69 for WC, and 0.70 for SC.

The results of factor analysis are reportedin Table 2. In the sample studied, the itemscould be grouped into two different scales(instead of the 4 originally described forEDE 12.0D). The first scale, which account-ed for 43.7% of the entire variance of EDEscores, included the majority of the items;all the items from EC, WC, and SC, except“Reaction to prescribed weighing” werepart of this scale. The second scale was

composed of the items of “Restraint”, plus“Reaction to prescribed weighing” (whichwas originally assigned to WeightConcern), and accounted for 18.8% of vari-ance. Cronbach’s α of the two scales was0.78 and 0.73, respectively. Correlations ofscores of scales derived from factor analy-sis with those of originally described EDEscales are summarized in Table 3. The firstscale shows a higher correlation with EC,WC, and SC, while the second scale is cor-related to “Restraint”. The mean scores ofitems of the first scale (1.7±1.1 in males,2.8±1.3 in females; p<0.01 with Student’s ttest, and p<0.05 with Mann-Whitney U test,between sexes) were inversely correlated toage (r=-0.29, p<0.01), but not BMI (r=-0.11,p= NS). The items of the second scalederived from factor analysis were not relat-ed to age (r=-0.03, p=NS) or BMI (r=-0.11,p=NS).

In order to exclude sex differences inEDE 12.0D factor structure, factor analysiswas also performed separately on femalepatients. This analysis was not performedin males, because the size of the samplewas inadequate. The factor structure ofEDE 12.0D in female patients was identicalto that observed in the whole sample (datanot shown).

DISCUSSION

EDE scores obtained in the present studywere somewhat higher than those reportedby Fairburn and Cooper (2). These differ-ences could be due either to the small sizeof the sample studied by Fairburn and

TABLE 1EDE 12.0D total and subscale scores.

Total sample Males Females

Restraint 2.1±1.5 1.5±1.8 2.2±1.3

Eating Concern 1.5±1.4 1.0±1.1 1.6±1.5

Shape Concern 2.7±2.0 1.5±1.5* 3.0±2.0

Weight Concern 3.0±1.8 2.1±1.1* 3.1±1.9

Total EDE scores 2.3±1.3 1.5±1.2** 2.5±1.3

*p<0.01 at Student’s t test, and p<0.05 at Mann-Whitney U test, vs females;**p=NS at Student’s t test, and p<0.05 at Mann-Whitney U test, vs females.

EDE 12.0D in obesity

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Cooper, or to differences in recruitmentprocedures and inclusion criteria.

Females showed higher total scores and“Shape Concern” scores compared tomales.

The inverse correlation of EDE total, SCand EC scores with age suggests thatyounger adults show greater psychopatho-logical disturbances related to eatingbehavior compared to older subjects. Nocorrelations were observed between EDEscores and BMI, indicating that, amongobese patients without BED, those withmore severe overweight do not present aworse psychological status related to eatingattitudes and behavior.

Factor analysis on the items of EDEidentified two subscales, instead of thefour described by Fairburn and Cooper(2). One of the newly identified subscaleswas composed of “Restraint”, items plus

“Reaction to prescribed weighing”, whichwas previously assigned to WC. It can bespeculated that those obese patients whoshow a marked attitude toward restraint,experience a greater distress whenweighing.

The other subscale derived from factoranalysis is composed of all the items of EC,WC, and SC, except “Reaction to pre-scribed weighing”. In obese patients, con-cerns for weight and body shape appear tobe closely related, while in patients withbulimia nervosa and anorexia nervosa theyseem to remain distinct. Disturbances ofbody image can be considered one of themost relevant psychological factorinvolved in the pathogenesis of formal eat-ing disorders, as confirmed in longitudinalstudies of populations at risk (26); weightconcern and attemps to control bodyweight can be considered as a conse-quence of body image disturbances (27).On the other hand, in obese patients,although disturbances of body image havebeen documented (28), weight gain deter-mines an objective worsening of bodyshape, so that the items WC and SC couldconverge in the same subscale. The itemsof EC were also assigned, through factoranalysis, to this subscale. It should be con-sidered that patients with Binge EatingDisorder were excluded from the samplestudied, which was therefore composedonly of subjects without formal eating dis-orders. Although episodic binge eating isnot unfrequent among obese patients with-out binge eating disorder, obese patientsappear to be much more afflicted by over-weight than by loss of control over eating;therefore, they seem to be concerned witheating mainly as a determinant of weightgain.

The two subscales derived from factoranalysis, which could be defined as“Restraint” and “Eating, Weight, andShape Concern”, showed a satisfactoryinternal consistency, as evaluated throughCronbach’s alfa. As expected, neither ofthe two scales was correlated to BMI.“Eating, Weight, and Shape Concern”showed a significant inverse coerrelationwith age, similar to that observed for theoriginal “Shape Concern”. On the otherhand, the “Restraint” subscale derivedfrom factor analysis was not significantlylower in older patients, indicating thatmotivations other than shape and weight

TABLE 2Factor analysis of EDE 12.0D in obese patients. Factor loading

of individual items.

Factor Factor

Items 1 2

4 Empty stomach 0.62

2 Restraint over eating 0.53

5 Food avoidance 0.50

3 Avoidance of eating 0.49

6 Dietary rules 0.65

7 Preoccupation with food, eating or calories 0.56

8 Fear of losing control over eating 0.51

12 Eating in secret 0.51

11 Social eating 0.42

22 Reaction to prescribed weighing 0.68

20 Desire to lose weight 0.65

19 Dissatisfaction with weight 0.62

13 Guilt about eating 0.60

24 Preoccupation with shape or weight 0.50

23 Dissatisfaction with shape 0.49

28 Discomfort seeing body 0.65

26 Importance of weight 0.62

25 Importance of shape 0.60

29 Avoidance of exposure 0.59

Factor 1: Figenvalue 8.71, Var. 43.7%Factor 2: Eigenvalue 3.75, Var. 18.8%

E. Mannucci, V. Ricca, M. Di Bernardo, et al.

REFERENCES

1. Cooper Z., Fairburn C.G.: The eating disor-der examination: a semistructured interviewfor the assessment of the specificpychopathology of eating disorders. Int. J.Eating Disord., 6, 1-8, 1987.

2. Fairburn C.G., Cooper Z.: The EatingDisorder Examination. In: Fairburn C.G.,Wilson G.T. (Eds.), Binge Eating: Nature,assessment and treatment, ed. 12. New York-London, Guilford Press, 1993, pp. 317-360.

3. American Psychiatry Association, Diagnosticand Statistical Manual of Mental Disorders,ed. 4, Washington DC., A.P.A. Press, 1994.

4. Cooper Z., Cooper P.J., Fairburn C.G.: Thevalidity of the Eating Disorder Examinationand its subscales. Br. J. Psychiatry 154, 807-812, 1989.

5. Beaumont P.J.V., Kopec-Schrader E.M.,Talbot P., Toyouz S.W.: Measuring the spe-cific psychopathology of eating disorderedpatients. Austr. N. Z. J. Psychiatry, 27, 506-511, 1993.

6. Rosen J.C., Vara L., Wendt S., Leitenberg:H.: Validity studies of the Eating disorderExamination. Int. J. Eating Disord., 9, 519-528, 1990.

7. Rosen J.C., Srebnik D.: The assessment of eat-ing disorders. In: McReynolds P., Rosen J.C.,Chelune G. (Eds.), Advances in psychologicalassessment. New York, Plenum, Press, 1991.

8. Fairburn C.G., Beglin S.J.: The assessmentof eating disorders: interview or self-reportquestionnaire? Int. J. Eating Disord., 16,363-370, 1994.

9. Wilson G.T., Smith D.: Assessment of bulim-ia nervosa: an evaluation of the EatingDisorder Examination. Int. J. Eating Disord.,86, 173-179, 1989.

10. Marcus M.D., Smith D., Santelli R., Kaye W.:Characterization of eating disorderedbehavior in obese binge eaters. Int. J. EatingDisord., 12, 249-256, 1992.

11. Taylor A.V., Peveler R.C., Hibbert G.A.,Fairburn C.G.: Eating disorders amongwomen receiving treatment for an alcoholproblem. Int. J. Eating Disord., 14, 147-151,1993.

12. Wilson G.T., Eldredge K.L., Smith D., NilesB.: Cognitive-behavioural treatment withand without response prevention in bulimia.Behav. Res. Ther., 29, 575-583, 1991.

13. Fairburn C.G., Jones R., Peveler R.C., HopeRA., O’Connor A.: Psychotherapy andbulimia nervosa: the longer-term effects ofinterpersonal psychotherapy, behaviourtherapy and cognitive-behaviour therapy.Arch. Gen. Psychiary, 48, 463-469, 1993.

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concern (i.e. health concern) could main-tain dietary restriction with advancingage.

In most of the previously reported studiesEDE 12.0D was used in female patients,while the present sample consisted of bothmales and females. Factor analysis per-formed separately on female patientsshowed an identical factor structure to thatobserved in the whole sample; therefore,the reported organization of subscales doesnot depend upon the inclusion of malepatients in the sample.

It is noteworthy that to date no studieshave been reported about the factor struc-ture of EDE in other populations ofpatients. It would be of great interest toassess factor analysis-derived organizationof EDE 1 2.0D scales in other clinical (i.e.,patients with anorexia nervosa, bulimianervosa, or binge eating disorder) or non-clinical (i.e., obese and normal weight sub-jects) samples, in order to verify if thedescribed two-scale structure is typical ofobese patients without binge eating disor-der.

In conclusion, EDE 12.0D appears to pro-vide relevant information about the psy-chopathological status of obese patientswithout Binge Eating Disorder; however, adifferent grouping of items into subscalescould be indicated in this population ofpatients, in order to provide a more accu-rate description of their clinical features.

ACKNOWLEDGEMENTS

The authors wish to thank Dr. C.G. Fairburn forthe precious advice and encouragement in thepreparation of this manuscript.

TABLE 3 Correlations of scores of scales derived from factor analysis with

those of originally described EDE scales.

Scales derived from factor analysis 1 2

Restraint 0.38** 0.97**

Eating Concern 0.78** 0.30*

Shape Concern 0.85** 0.33**

Weight Concern 0.77** 0.38**

*p<0.05, **p<0.01

EDE 12.0D in obesity

21. Marcus M.D.: Binge eating in Obesity. In:Fairburn C.G., Wilson G.T. (Eds.), BingeEating: Nature, assessment and treatment.New York-London, Guilford Press, 1993, pp.77-96.

22. Pagano R., La Vecchia C.: Overweight andobesity in Italy 1990-1991. Int. J. Obes., 18,665-672, 1994.

23. Kuczmarski R.J.: Prevalence of overweightand weight gain in the United States. Am. J.Clin. Nutr., 557, 495s-502s, 1992.

24. Mannucci E., Ricca V., Di Bernardo M.,Rotella C.M.: Studio del comportamento ali-mentare con un’intervista strutturata: laEating Disorder Examination. Il Diabete, 8,127-131, 1996.

25. Spitzer R.L., Williams J.B.W., Gibbon M.,First M.B. Structured Clinical Interview forDSM-III-R (SCID).Washington D.C.,American Psychiatric Press, 1990.

26. Cash T.F., Pruzinsky T. Body images:Development, deviance, and change. NewYork, Guilford Press, l990.

27. Rosen J.C.: Body image disorder: Definition,development and contribution to eating dis-orders. In: Crowther J.H., Tennenbaum D.L.,Hobfoll S.E., Stephens M.A.P. (Eds.), Theetiology of bulimia: The individual andfamilial context. Washington D.C.,Hemisphere Publishing, 1990, pp. 157-177.

28. Stunkard A.J., Wadden T.A.: Psychologicalaspects of severe obesity. Am. J. Clin. Nutr.55, 524s-532s, 1992.

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14. Garner D.M., Rockert W., Davis R., GarnerM.V., Olmsted M.P., Eagle M.: A compari-son between cognitive-behavioural and sup-portive-expressive therapy for bulimia ner-vosa. Am. J. Psychiatry 163, 195-200, 1993.

15. Greeno C.G., Marcus M.D., Wing R.R.:Diagnosis of binge eating disorder: discrep-ancies between a questionnaire and clinicalinterview. Int. J. Eating Disord., 17, 153-160,1995.

16. de Zwann M., Mitchell J.E., Specker S.M., PyleR.L., Mussell M.P., Seim H.C.: Diagnosingbinge eating disorder: lack of agreementbetween self-report and expert rating. Int. J.Eating Disord., 14, 289-295, 1993.

17. Fairburn C.G., Stein A.P., Jones R.: Eatinghabits and eating disorders during pregnan-cy. Psychosom. Med., 54, 665-672, 1992.

18. Fairburn C.G., Peveler R.C., Davies B.,Mann J.I., Mayou R.A.: Eating disorders inyoung adults with insulin-dependent dia-betes mellitus: a controlled study. Br. Med.J., 303, 17-20, 1991.

19. Peveler R.C., Fairburn C.G., Boller I.,Dunger D.: Eating disorders in adolescentswith insulin-dependent diabetes mellitus. Acontrolled study. Diabetes Care 15, 1356-1360, 1992.

20. Striege-Moore R.H., Nicholas T.J.,Tamborlane W.V.: Prevalence of eating dis-order symptoms in preadolescent and ado-lescent girls with lDDM. Diab. Care 15,1361-1368, 1992.