Ad&rive Behaviors, Vol. 16, pp. 89-93, Printed in the USA. All rights reserved.

1991 Copyright

0306-4603/91 $3.00 + .oO 0 1991 Pergamon Press plc

BRIEF REPORT CONSTRUCT VALIDITY AND FACTOR STABILITY OF THE ANORECTIC COGNITIONS QUESTIONNAIRE J. SCOTT MIZES Department of Psychiatry, MetroHealth Medical Center, and Case Western Reserve University School of Medicine Abstract - Specific cognitive distortions may be central to the psychopathology of anorexia nervosa and bulimia nervosa; however, few psychometrically adequate instruments exist to assess these cognitions. The Mizes Anorectic Cognitions (MAC) questionnaire was previously developed to till this need. The present study examined the construct validity, temporal reliability, and factor stability of the MAC in a sample of 100 college females. Results suggested excellent construct validity and test-retest reliability. Moreover, the three previously identified factors (i.e., SelfControl, Weight and Approval, Rigid Weight Regulation) were cross-validated in this sample.

Several authors have emphasized cognitive distortions in anorexia and bulimia nervosa (Fairburn, 1985; Garner & Bemis, 1982; Mizes, 1985). In general, three areas of cognitive distortion have been delineated: rigid weight regulation, weight as the basis of self-esteem and other approval, and excessive self-control as the basis of self-esteem. However, there are few psychometrically adequate devices to measure these presumed cognitions. Although the Bulimia Cognitive Distortions Scale (BCDS) (Schulman, Kinder, Powers, Prange, & Gleghom, 1986) exists, it has limitations. First, it assesses only the weight and approval dimension of the three domains described by Garner and Bemis (1982). Second, one BCDS subscale appears to assess eating associated behaviors more than cognitions. In contrast, the Mizes Anorectic Cognitions (MAC) questionnaire was developed to assess all three of the cognitive domains hypothesized to be relevant in anorexia and bulimia nervosa. To date, three studies have investigated the psychometric properties of the MAC. Mizes and Klesges (1989) reported on the initial development of MAC items. As well, concurrent validity was assessed, and the MAC showed expected differences vis-Lvis relative weight and sex, and was correlated with measures of eating pathology. A principal components analysis empirically confirmed the three theoretically defined factors. The coefficient alpha for the full scale was .91, and ranged from .75 to .89 for the subscales. Mizes (1988) found that bulimics scored significantly higher on the MAC than did noneating disordered controls, and that the MAC accounted for 60% of the between groups variance. Finally, Mizes (1990) found that high MAC scorers had a greater general emphasis on weight regulation, rated higher the relative importance of specific benefits of losing or maintaining weight (i.e., psychologic and appearance), used more calorie restriction strategies, and, to a lesser extent, used more strategies to increase calorie expenditure.

Thanks to the Psychology Department at Bloomsburg University for allowing access also to Anne Farrell for her invaluable assistance in data collection and data analysis, comments on an earlier draft of the article. Portions of this research were supported Geisinger Research Foundation. Requests for reprints should be sent to J. Scott Mizes, Ph.D., ABPP, Department Medical Center, 3395 Scranton Road, Cleveland, OH 44109. 89

to their subject pool. Thanks and to John Norcross for his in part by a grant from the of Psychiatry,

MetroHealth

90

J. SCOTT MIZES

The purpose of the current investigation was threefold: first, to examine the construct validity of the MAC; second, to attempt to replicate the previously identified factor structure; and third, to examine test-retest reliability and internal consistency. METHOD

Subjects

Female undergraduates (N = 100) participated in the study in order to fulfill course requirements. The sample had the following demographic characteristics: 98% were never married, while 2% were divorced; 39% were Catholic, 44% Protestant, 1% Jewish, 12% other miscellaneous religions, and 4% no religious affiliation. For the group, the average self-reported weight was 130.7 pounds (SD = 21 .O), and the average height was 64.9 inches (SD = 2.4). Using DHEW (1977) age, sex, and height adjusted norms, the sample’s weight was very near the 50th percentile weight of 130 pounds. The mean age was 18.5 years (SD = 1.7). Measures

and procedure

Students completed questionnaires anonymously in a group format. They responded to the MAC, a brief demographics questionnaire, and to several other standardized psychologic tests. The MAC has been extensively described elsewhere (Mizes & Klesges, 1989). Briefly, the full MAC consists of 45 items scored in a Likert format using a l-5 rating. A shorter, 33-item version of the scale was developed after identifying items that were not highly correlated with the total score. From this shorter version, three subscales have been identified: Weight Regulation (20 items), Self-Control (6 items), and Weight and Approval (7 items). I Convergent measures were the following: the BULIT, a measure of the diagnostic criteria for bulimia (Smith & Thelen, 1984); the Gormally Cognitive Factors in Binge Eating Scale (COGFAC) (Gormally, Black, Daston, & Rardin, 1982), which assesses rigid dieting and low self-efficacy regarding control of eating; the Eating Attitudes Test-26 (EAT-26) (Garner & Garfinkle, 1979), which assesses several presumed symptoms of anorexia nervosa and bulimia (e.g., urge to vomit, engaging in dieting behavior, guilt after eating, etc.); and a general measure of cognitive distortion, the Rational Behavior Inventory (RBI) (Whiteman & Shorkey, 1978). Higher scores on the RBI represent more rational thinking. Divergent measures were: the Marlow-Crowne Social Desirability Scale (MCSD) (Crowne & Marlow, 1964) to assess tendency for socially desirable response sets; the spelling (WRAT-S) and arithmetic (WRAT-A) subscales of the Wide Range Achievement Test (Jastak & Jastak, 1976) to assess academic ability (raw scores were used); and the subscales of the Jenkins Type A Scale (Jenkins, Zyzanski, & Rosenman, 1979), including TYPE A, speed and impatience (SPEED), job overinvolvement (JOB), and hard driving (DRIVE). The WRAT subscales were administered first according to group oral administration procedures. All the other questionnaires were presented in a random order. The MAC was readministered to 86% of the initial sample 2 months later. RESULTS

The overall mean total score on the MAC was 107.92 (SD = 27.2), which is nearly identical to previously reported averages for college females (Mizes & Klesges, 1989). The re-test mean was 104.0 (SD = 25.0). The mean for the 33-item MAC was 80.3 (SD = 22.4). The subscale means were the following: Weight Regulation, 44.8 (SD = 14.5); ‘Copyrighted copies of the MAC, scoring criteria, and an IBM Basic scoring program from the original validation sample) are available by writing the author.

(using subscales derived

91

Construct validity of the MAC

Table 1. Rotated component loadings for the eating disorder construct and alternative constructs Constmct Scale Eating disorders BULIT EAT-26 MAC RBI COGEAT Other constructs TYPE A DRIVE JOB SPEED WRAT-S WRAT-A MCSD Rotated solution

Component

Loadings

Eating Disorders

Other

,864 ,774 ,863 - ,614 ,642

,086 ,188 -.127 -.167 -.I94

,176 - .008 -.164 ,375 ,083 - ,001 - ,303 26.47%

,872 ,785 .352 ,435 ,326 ,266 - ,034 16.61%

Self-Control, 20.0 (SD = 5.2); and Weight and Approval, 15.5 (SD = 5.2). The Pearson correlation for test-retest reliability was 0.78. The test-retest difference was not significant, t = 1.7, df = 86, p = .098. Coeff icient alpha for the full 45-item scale was .94, and for the shorter 33-item scale, .93. For the subscales (as derived from the original component analysis), the coefficient alphas were as follows: Self-Control, .77; Approval, .76, and Weight Regulation, .91. Pearson correlations were computed between the MAC and the convergent and divergent measures. The coefficients (allp < .05) for convergent measures were: .69 with the BULIT, .51 with the COGFAC, .64 with the EAT-26, and - .46 with the RBI. The correlations for divergent measures were: -.12 with the MCSD, .Ol with the WRAT-S, 0.0 with the WRAT-A, .08 with the TYPE A, 0.14 with the SPEED, -. 19 @ < .05) with the JOB, and .03 with the DRIVE. A principal components analysis with varimax rotation was conducted on the 12 questionnaire scores. The solution was a priori limited to two factors in order to represent the eating disorder construct versus alternative constructs. Component loadings are presented in Table 1. All the convergent measures loaded highest on the eating disorders component. For the divergent measures, only MCSD loaded highest on the eating disorders component. The individual items’ correlation with the total score was examined. As before, this supported the reduction to the 33-item version. Another principal components analysis with varimax rotation was conducted on the 33-item version. The scree test (Cattell, 1966) was used to judge the number of factors reflected in the data. The scree test is generally regarded as one of the most accurate rules for determining the number of components to retain (Cattell & Vogelman, 1977; Zwick & Velicer, 1986). Three components merited retention. For the rotated solution, the first component (‘ ‘Self-Control’ ‘) accounted for 18.3% of the variance, the second component (“Weight and Approval”) accounted for 10.6%, and the third component (‘ ‘Rigid Weight Regulation”) accounted for 18.3%. Total variance accounted for was 47.2%.*

*The loadings for the individual

33 items on the 3 components

are available by writing the author.

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J. SCOTT MIZES

Items were reassigned to subscales using rules similar to those used in the original sample.3 To be considered a marker item, the component loading had to be greater than or equal to .40. Only 1 of the MAC items did not meet this criterion. There was 70% agreement on assignment of specific items to subscales between the original and cross-validation samples. For the Weight Regulation subscale (20 items), 1 item shifted to the Approval subscale, and 7 to Self-Control subscale in the cross-validation sample, For the Approval subscale (7 items), 2 items shifted to the Self-Control subscale. All the original Self-Control items stayed on the subscale. DISCUSSION

The construct validity of the MAC was well supported. It was shown to be highly related to measures of eating-disorder symptoms, cognitions associated with binge eating, and general irrational thinking. It was also shown to be orthogonal to measures of theoretically unrelated constructs such as academic ability and coronary prone behavior. While a measure of social desirability did load on the eating disorder factor, this is not entirely unexpected given the approval concerns of eating disorder patients (Mizes, 1988). However, the absolute level of the correlation was not significant. The reliability and component stability of the MAC was strongly supported. Very good test-retest reliability and internal consistency was shown. The tridimensional conceptualization of eating disordered cognitions was replicated. However, the assignment of individual items to components showed some change across samples. The most conservative view would suggest that the specific subscale scoring of the MAC should be viewed as preliminary at this time. This is the fourth study to support the psychometric properties of the MAC. Nonetheless, further validational work is warranted. One direction is to assess the MAC’s ability to discriminate eating disorders from other types of psychopathology to demonstrate that the cognitive distortions assessed by the MAC are eating-disorder specific. It would also be useful to compare MAC scores in various eating disorders (i.e., anorectics, bulimics, dieters). As well, examination of the basic psychometric properties of the MAC in large samples of eating disorder patients would be useful.

REFERENCES Cattell, R.B. (1966). The scree test for the number of factors. Multivariate Behavioral Research, 1, 245-276. Cattell, R.B., & Vogelman, S. (1977). A comprehensive trial of the scree and KG criteria for determining the number of factors. Multivariate Behavioral Research. 12, 289-325. Crowne, D.P., & Marlow, D. (1964). The approval motive: studies in evaluative dependence. Westport, CT: Greenwood Press. Department of Health, Education, and Welfare (1977). Weight by heighr and age for adults 18-74 years: U.S. 1971-1974. DHEW Publication No. 79-1656, Series 11, No. 280, Hyattsville, MD. Fairbum, C.G. (1985). A cognitive-behavioral treatment of bulimia. In D.M. Garner & P.E. Garfinkle (Eds.), Handbook ofpsychotherapy for anorexia nervosa and bulimia (pp. 160-192). New York: Guilford. Garner, D.M., & Bemis, K.M. (1982). A cognitive-behavioral approach to anorexia nervosa. Cognirive Therapy and Research, 6, 123-150. Gamer, D.M., & Garfmkle, P.E. (1979). The eating attitudes test: An index of the symptoms Psychological Medicine, 9, 273-279.

of anorexia nervosa.

‘In the original study (Mizes & Klesges, 1989), items were retained if they loaded at least 2 .40 on the primary component, and less than or equal to I? .40 on the other component. Adherence to this strict criterion in the current study would have resulted in seven items being dropped from the scale. These items were retained for two reasons: first, to maintain a desirable questionnaire length; and second, since these items had shown desirable characteristics in the previous larger study, it seemed appropriate to retain them. By doing so, this allows future research on these items using larger samples that may again suggest the relative component purity of these items.

Construct

validity of the MAC

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Gormally, J., Black, S., Daston, S.. & Rardin, D. (1982). The assessment of binge eating severity among obese persons. Addictive Behaviors, 7, 41-55. Jastak, J.F., & Jastak, S.R. (1976). Manual for he wide range achievementtest. Wilmington, DE: Guidance Association of Delaware, Inc. Jenkins, D.C., Zyzanski, S.J., & Rosenman, R.H. (1979). JenkinsActivity Survey manwl. New York: The Psychological Corporation. M&s, J.S. (1985). Bulimia: A review of its symptomatology and treatment. Advances in Behavior Research and Therapy, 7, 91-142. Mizes, J.S. (1988). Personality characteristics of bulimic and non-eating disordered female controls: a cognitive behavioral perspective. International Jourm~l of Eating Disorders, 7, 541-550. Mizes, J.S. (1990). Criterion-related validity of the Anorectic Cognitions questionnaire. AddictiveBehaviors, 15, 153-163. Mizes, J.S., & Klesges, R.C. (1989). Validity, reliability, and factor structure of the Anorectic Cognitions questionnaire. Addictive Behaviors, 14, 589-594. Schulman, R.G., Kinder, B.N., Powers, P.S., Prange, M., & Gleghom, A. (1986). The development of a scale to measure cognitive distortions in bulimia. Journal of Personuliry Assesstnenr, 50, 630-639. Smith, M.C., & Thelen, M.H. (1984). Development and validation of a test for bulimia. Journal of Consulting and Clinical Psychology, 52, 863-872. Whiteman, V.. & Shorkey, C. (1978). Validation testing of the rational behavior inventory. Educational and Psychological Measurement, 38, 1143-l 149. Zwick, W.R., & Velicer, W.F. (1986). Comparison of five rules for determining the number of components to retain. Psychological Bulletin, 99, 4324.

Construct validity and factor stability of the anorectic cognitions questionnaire.

Specific cognitive distortions may be central to the psychopathology of anorexia nervosa and bulimia nervosa; however, few psychometrically adequate i...
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