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Journal of Consulting and Clinical Psychology April 2000 Vol. 68, No. 2, 346-350
© 2000 by the American Psychological Association For personal use only--not for distribution.
Effectiveness of an Internet-Based Program for Reducing Risk Factors for Eating Disorders Andrew J. Winzelberg Department of Psychiatry Stanford University School of Medicine Dori Eppstein Department of Psychology San Diego State University Kathleen L. Eldredge Department of Psychiatry Stanford University School of Medicine Denise Wilfley Joint Doctoral Program in Clinical Psychology San Diego State University Radhika Dasmahapatra Department of Psychiatry Stanford University School of Medicine C. Barr Taylor Department of Psychiatry Stanford University School of Medicine Parvati Dev University of California, San Diego ABSTRACT
This study evaluated an Internet-delivered computer-assisted health education (CAHE) program designed to improve body satisfaction and reduce weight/shape concerns–concerns that have been shown to be risk factors for the development of eating disorders in young women. Participants were 60 women at a public university randomly assigned to either an intervention or control condition. Intervention participants completed the CAHE program Student Bodies. Measures of body image and disordered eating attitudes were assessed at baseline, postintervention, and 3-month follow-up. At follow-up, intervention participants, compared with controls, reported a significant improvement in body image and a decrease in drive for thinness. This program provides evidence for the feasibility and effectiveness of providing health education by means of the Internet.
This study was supported in part by funds from the Campbell Soup Foundation and the McKnight Foundation. Correspondence may be addressed to Andrew J. Winzelberg, Department of Psychiatry, Stanford University School of Medicine, Stanford, California, 94305-5722. Electronic mail may be sent to
[email protected] Received: June 9, 1998 Revised: June 30, 1999 Accepted: July 12, 1999
Eating disorders are widespread among college students. Approximately 1% to 2% of the young adult http://spider.apa.org/ftdocs/ccp/2000/april/ccp682346.html
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Page 2 of 8 population suffers from bulimia nervosa ( Bushnell, Wells, Hornblow, Oakley-Brown, & Joyce, 1990 ; Fairburn & Beglin, 1990 ), and the prevalence of unhealthy dietary practices, on the basis of the self-report of female adolescents and young adults, ranges from 5% to 79% ( Fairburn & Beglin, 1990 ). Twenty-five percent of college women are thought to be at risk of developing eating disorders ( Drewnowski, Yee, Kurth, & Krahn, 1994 ). A number of studies using cross-sectional and clinical populations have identified various cultural, familial, and personal factors that are associated with eating disorders ( Taylor et al., 1998 ). Excessive weight concerns, a drive for thinness, and related factors (such as poor body image) appear to be common risk factors ( Taylor & Altman, 1997 ). More recently, longitudinal studies have linked excessive weight concerns with subclinical and clinical eating disorders (e.g., Killen et al., 1996 ). Although body dissatisfaction has not been shown to be a risk factor for eating disorders in prospective studies, a recent meta-analysis by Cash and Deagle (1997) demonstrated that women with eating disorders have greater body dissatisfaction than controls and that the construct is very similar to weight/shape concerns. Presumably, a reduction in weight/shape concerns and improvement in body image might, in turn, reduce the onset of eating disorders. About one third of women who develop eating disorders do so in college ( Woodside & Garfinkel, 1992 ). Although eating disorder prevention programs are widespread on college campuses ( Mann et al., 1997 ), only a few eating disorder prevention curricula have been evaluated. Those programs that have focused on knowledge have demonstrated that prevention curricula increase students' knowledge of the relevant content ( Shisslak, Crago, & Neal, 1990 ). However, the majority of educational prevention programs designed to change attitudes and behaviors associated with disordered eating have had little or no effect ( Mann et al., 1997 ; Taylor & Altman, 1997 ). Two recent studies, however, have found that preventive interventions may be effective. Winzelberg et al. (1998) found that participants who used a CD-ROM-based psychoeducational eating disorders prevention program with an E-mail discussion group were able to improve their body image, as well as adopt healthier eating attitudes and behaviors. A second study, consisting of an academic course, found moderate changes among college women who were not at high risk for developing eating disorders ( Springer, Winzelberg, Perkins, & Taylor, 1999 ). To reach the target population (approximately 25% to 35% of college women), interventions will need to be relatively inexpensive and standardized and have built-in potential for dissemination. For these reasons, it is important to consider programs that are easier to deliver than face-to-face therapy. There is evidence that non-therapist-conducted interventions based on cognitive—behavioral therapy principles are effective in reducing symptoms in subclinical populations ( Fairburn & Carter, 1996 ). For instance, Huon (1985) found that 32% of individuals with bulimia who used self-help materials were symptom free 6 months following their use and that 45% reported significant improvements. Self-directed cognitive—behavioral body image therapy, with modest therapist contact, has also been found to improve body satisfaction ( Grant & Cash, 1995 ). Interactive multimedia computer programs have great promise as a method to present self-help and manualized programs. Computer-assisted health education (CAHE) programs can tailor the interventions presented depending on the user's needs. The CAHE can query for comprehension and repeat the presentation of information that is misunderstood. Like bibliotherapy and video training, CAHE can be used any time without scheduling problems, is inexpensive, and can be used frequently for brief periods of time. Once programs have been demonstrated to be effective, they can be inexpensively disseminated. The present study was an extension of preliminary work with the Student Bodies program ( Winzelberg et al., 1998 ), originally developed as a CD-ROM and as an E-mail discussion group. The program was revised to offer Internet delivery, with the discussion group integrated into the program. The program was also redesigned to focus on change in body image. http://spider.apa.org/ftdocs/ccp/2000/april/ccp682346.html
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Method Participants Participants were female students from a West Coast public university. Participants were recruited through campus newspaper advertisements, fliers, and presentations given in dormitories and sororities. The only entrance requirement was a desire to improve body image satisfaction. Participants were ineligible if they reported, during the intake interview or on self-report forms, a history of bulimia or anorexia nervosa; if they currently engaged in purging behaviors; or if they had a body mass index below 18 on height/weight measurements. Each participant who completed the study received $25. Description of the Student Bodies Program The Student Bodies program incorporates interventions and ideas for improving body image and developing healthy dietary practices developed by Cash (1991) , Davis et al. (1989) , and Taylor and Altman (1997) , but the interactive content is unique to itself and the delivery technology. The Student Bodies program was conducted as a structured 8-week intervention delivered through the Internet. The program began with an overview that included a description of the development and consequences of eating disorders. A primary focus of each week related to improvement in body image. Program content discussed cultural determinants of beauty, the role of the media, and cognitive—behavioral strategies for improving body satisfaction. The interactive software featured text, audio and video components, on-line self-monitoring journals, and behavior change exercises. Participants were given mandatory and optional assignments to complete each week. Participants could also use sections at any time that helped them adopt healthy eating and exercise practices. Each week, participants were expected to post a message to the discussion group related to the psychoeducational focus of that week and to answer or comment on at least one other message. Adherence to the program was collected electronically. Participants who missed assignments were contacted by E-mail by research assistants who encouraged them to complete the assignments. The goal of the on-line discussion group was to provide a forum for participants to receive and provide emotional support and to discuss their reactions to the software content. Participants could label their postings as just sharing , success story , or want feedback . Participants participated in the discussion group using anonymous log-on names. The moderator, a graduate student in clinical psychology, was responsible for maintaining the discussion, periodically reflecting on the concerns expressed by the participants and offering suggestions based on the content of the Student Bodies software. Measures The primary dependent measure used in this study was the Body Shape Questionnaire (BSQ; Cooper, Taylor, Cooper, & Fairburn, 1987 ). The BSQ has coefficients of internal consistency, test—retest reliability, and concurrent validity with other measures of body satisfaction of .97, .88, and .66, respectively ( Rosen, Jones, Ramirez, & Waxman, 1996 ). Secondary dependent measures included the Eating Disorder Inventory (EDI) Drive for Thinness and Bulimia subscales ( Garner & Olmsted, 1984 ) and the Eating Disorder Examination–Questionnaire (EDE—
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Page 4 of 8 Q) Weight Concerns and Shape Concerns subscales ( Fairburn & Beglin, 1994 ). Cronbach's alphas for the EDI subscales were between .65 and .90, and the EDE—Q Weight Concerns and Shape Concerns subscales correlated .79 and .80 with the corresponding EDE subscales ( Fairburn & Beglin, 1994 ). The EDI subscales were scored as continuous measures in order to differentiate "subclinical" response variations ( Schoemaker, van Strien, & van der Staak, 1994 ). Using Pearson correlations, we found that, at baseline, the BSQ correlated .89 with the EDE—Q Shape Concerns subscale, .82 with the EDE—Q Weight Concerns subscale, and .80 with the EDI Drive for Thinness subscale. These high correlations suggest that the BSQ measures the same construct as weight/shape concerns. At posttest, intervention participants also completed a 4-item On-Line Social Support Scale adapted from the Multidimensional Scale of Perceived Social Support (MSPSS; Dahlem, Zimet, & Walker, 1991 ) and a 24-item open-ended questionnaire assessing their qualitative experience with the software. Previous studies have shown the MSPSS to have good reliability ( Dahlem et al., 1991 ). The four scores were averaged into a single score in the present analysis. Compliance to program requirements was measured as the percentage of weekly assignments participants completed each week. An overall compliance rate was calculated as the percentage of all assignments completed. These data were collected by electronically tracking the sections of the program used by each participant. On-Line Discussion Group The discussion group postings were analyzed by frequency and theme. Two raters read each message and then conjointly categorized the message into the following six categories: (a) self-disclosure, (b) body shape concerns, (c) support to others, (d) weight concerns, (e) frustration, and (f) cognitive work on body image. Participants completed baseline measures and were then randomly assigned to Student Bodies or a delayedintervention control group. Participants were assessed at baseline, at postintervention (8 weeks), and at follow-up (3 months; follow-up data were obtained on the delayed intervention). Data Analysis We analyzed postintervention and follow-up scores using the analysis of covariance procedure (with p values set for a two-tailed test). Participants' baseline scores were added as a covariate on all the analyses to adjust for the baseline value of the outcome being predicted. We performed an intention-to-treat analysis using baseline measures in place of missing postintervention or follow-up data. An alpha level of .50 was used for all of the statistical tests.
Results Sixty participants (31 intervention, 29 control) completed baseline measurements. Fifty-three percent of these participants identified themselves as Caucasian, 35% as Hispanic, 5% as Asian, 3% as African American, and 3% as "other." The average age of participants was 20.0 years ( SD = 2.8, range = 18—33). There were no significant differences on any demographic or baseline measures between control and intervention groups. Of the 60 participants, 8 (4 intervention, 4 control) dropped out during the pre—post
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Page 5 of 8 intervention period. An additional 8 participants (3 intervention, 5 control) did not complete the 3-month follow-up. Completer Analysis: Intervention Effects For participants who completed all of the measures (see Table 1 ), significant differences between intervention and control groups were found at follow-up after statistically controlling for baseline scores on the BSQ, F (1, 41) = 5.78, p = .021, and the EDI Drive for Thinness subscale, F (1, 41) = 4.29, p = .045. No other measures were found to differ significantly between the two groups. The baseline-topostintervention and baseline-to-follow-up effect sizes on the BSQ for the intervention group were 0.40 and 0.70, respectively. Intention-to-Treat Analysis We also analyzed the data by intention to treat, which included all of the dropouts. At posttest, no significant differences were found after controlling for baseline scores. However, at follow-up, three measures showed significant differences between intervention and control: the BSQ, F (1, 57) = 7.74, p = .007; the EDI Drive for Thinness subscale, F (1, 57) = 5.38, p = .024; and the EDI Bulimia subscale, F (1, 57) = 6.18, p =.016. High-BSQ Analysis Participants with a BSQ score of 110 or greater were considered to have scored high enough to put them at high risk for developing bulimia. On the basis of Cooper et al.'s (1987) data, we defined the cutoff as 1 SD below the mean score reported by probable bulimic individuals. Because of unequal numbers between the intervention and control groups, and the low number of participants with a BSQ score of 110 or greater, no statistical analyses were performed. However, as can be seen in Table 2 , for the 16 high-BSQ participants in the intervention with data available at all of the time points, the BSQ score dropped from a mean of 138 ( SD = 21) at baseline, to a mean of 113 ( SD = 33) at postintervention, to a mean of 104 ( SD = 21) at follow-up; no similar trend was found in the control group. Compliance Analyses Intervention participants ( n = 23) completed an average of 64% ( SD = 26) of the weekly assignments. Compliance declined from approximately 70% to 40% over the course of the study. There were no differences in compliance between high-BSQ and non-high-BSQ participants. To determine the relationship between compliance and primary outcomes, we completed a stepwise regression analysis with the baseline value of the outcome variable entered first, followed by compliance. This procedure accounts for any potential effects of baseline scores on outcome before examining the contribution of compliance and was completed on the postintervention and follow-up scores of the primary outcome measures (the BSQ, the EDI Drive for Thinness subscale, and the EDE Weight and Shape Concerns subscales). No significant relationships were found between compliance and outcome variables, except for the BSQ at follow-up, for which compliance accounted for 14% of the variance (β = −0.299), F (2, 18) = 5.71, p = .03. Analysis of On-Line Discussion Group Participants posted a total of 244 messages to the discussion group. The average number of postings per http://spider.apa.org/ftdocs/ccp/2000/april/ccp682346.html
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Page 6 of 8 participant over the 8 weeks of the intervention was 10.6 ( SD = 9.5). The messages were identified as having the following themes: self-disclosure (79%), cognitive work on body image (67%), body shape concerns (50%), support/reply to others (32%), weight concerns (25%), and frustration (12%). Of note, messages could be coded for more than one theme. Social Support Participants reported receiving a moderate amount of social support from the discussion group ( M = 4.7, SD = 1.3, on a 7-point scale). Qualitatively, participants reported that (a) they could talk about their concerns in the discussion group, (b) group members understood their concerns, (c) they trusted the advice they received from group members, and (d) they felt supported by members of the group. Perception of social support was not significantly correlated with a participant's total number of postings to the discussion group.
Discussion This study suggests that an Internet-delivered CAHE program can improve women's body satisfaction, a potential risk factor in the development of eating disorders. Although there were no significant differences between intervention and control groups at postintervention, the intervention participants continued to improve between the postintervention and follow-up assessments. At follow-up, significant differences were found between the intervention and control groups on the BSQ and on the EDI Drive for Thinness subscale. To our knowledge, this is the first study to demonstrate that significant changes in body image satisfaction can be produced by completion of an Internet-delivered CAHE program. Despite these positive results at follow-up, Student Bodies and programs like Student Bodies need much more evaluation and development. Compliance with CAHE remains a challenge. On average, participants completed less than two thirds of the program and weekly compliance decreased over the course of the intervention. Because compliance was significantly related to improvement on the BSQ, improving compliance might improve the outcome. Compliance might be improved by stressing the importance of adherence to participants at the onset of their participation, embedding motivational components into the software, and offering incentives for completing the program. Despite the high level of participation in the discussion group, participants reported receiving only a moderate level of social support from the group. Further studies will need to be undertaken to determine how more supportive discussion groups can be developed and if higher levels of support increase the effectiveness of CAHE programs. Issues of privacy in the use of Internet programs (including moderated groups) remain an issue for this approach. For instance, any information obtained on participants should be considered potentially vulnerable to determined hackers. If participants elect to use their real identities (names or E-mail addresses), they must be cautioned on the limits of confidentiality. Although the results of this study are encouraging, caution is urged in generalizing from these results. Future studies should determine the long-term effects of this CAHE program and the efficacy of this intervention with other populations. Strategies to improve adherence and to improve the effectiveness of the intervention need to be developed and evaluated. However, if these programs are found to be effective, they have the potential to reduce the incidence of subclinical/clinical eating disorders in at-risk populations.
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References Bushnell, J. A., Wells, J. E., Hornblow, A. R., Oakley-Browne, M. A. & Joyce, P. (1990). Prevalence of three bulimia syndromes in the general population. Psychological Medicine, 20, 671-680. Cash, T. F. (1991). Body image therapy: A program for self-directed change. (New York: Guilford Press) Cash, T. F. & Deagle, E. A. (1997). The nature and extent of body-image disturbances in anorexia nervosa and bulimia nervosa: A meta-analysis. International Journal of Eating Disorders, 22, 107-125. Cooper, P., Taylor, M., Cooper, Z. & Fairburn, C. (1987). The development and validation of the Body Shape Questionnaire. International Journal of Eating Disorders, 6, 485-494. Dahlem, N., Zimet, G. & Walker, R. (1991). The Multidimensional Scale of Perceived Social Support: A confirmation study. Journal of Clinical Psychology, 47, 756-761. Davis, R., Dearing, S., Faulkner, J., Jasper, K., Olmsted, M., Rice, C. & Rockert, W. (1989). The road to recovery: A manual for participants in the psychoeducation group for bulimia nervosa. (Toronto, Ontario, Canada: Toronto Hospital, Toronto General Division) Drewnowski, A., Yee, D. K., Kurth, C. L. & Krahn, D. D. (1994). Eating pathology and DSM—III—R bulimia nervosa: A continuum of behavior. American Journal of Psychiatry, 151, 1217-1219. Fairburn, C. G. & Beglin, S. J. (1990). Studies of the epidemiology of bulimia nervosa. American Journal of Psychiatry, 147, 401-408. Fairburn, C. G. & Beglin, S. J. (1994). Assessment of eating disorders: Interview or self-report questionnaire? International Journal of Eating Disorders, 16, 363-370. Fairburn, C. G. & Carter, J. C. (1996). Self-help and guided self-help for binge eating problems.(In D. M. Garner & P. E. Garfinkel (Eds.), Handbook of treatment for eating disorders (pp. 494—499). New York: Guilford Press.) Garner, D. M. & Olmsted, M. P. (1984). Eating Disorder Inventory manual. (New York: Psychological Assessment Resources) Grant, J. R. & Cash, T. J. (1995). Cognitive—behavioral body image therapy: Comparative efficacy of group and modest-contrast treatments. Behavior Therapy, 26, 69-84. Huon, G. F. (1985). An initial validation of a self-help program for bulimia. International Journal of Eating Disorders, 4, 573-588. Killen, J. D., Taylor, C. B., Hayward, C. H., Haydel, F., Wilson, D., Hammer, L., Kraemer, H., BlairGreiner, A. & Strachowski, D. (1996). Weight concerns influence the development of eating disorders: A four-year prospective study. Journal of Consulting and Clinical Psychology, 64, 936-940. Mann, T., Nolen-Hoeksema, S., Huang, K., Burgard, D., Wright, A. & Hanson, K. (1997). Are two interventions worse than none? Joint primary and secondary prevention of eating disorders in college females. Health Psychology, 16, 215-225. Rosen, J., Jones, A., Ramirez, E. & Waxman, S. (1996). Body Shape Questionnaire: Studies of validity and reliability. International Journal of Eating Disorders, 20, 315-319. Schoemaker, C., van Strien, T. & van der Staak, C. (1994). Validation of the Eating Disorders Inventory in a nonclinical population using transformed and untransformed responses. International Journal of Eating Disorders, 15, 387-393. Shisslak, C., Crago, M. & Neal, M. E. (1990). Prevention of eating disorders among adolescents. American Journal of Health Promotion, 5, 100-106. Springer, E. A., Winzelberg, A. J., Perkins, R. & Taylor, C. B. (1999). Effects of a body image curriculum for college students. International Journal of Eating Disorders, 26, 13-20.
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Page 8 of 8 Taylor, C. B. & Altman, T. M. (1997). Priorities in prevention research for eating disorders. Psychopharmacology Bulletin, 33, 413-417. Taylor, C. B., Altman, T., Shisslak, C., Bryson, S., Estes, L. S., Gray, N., McKnight, K. M., Kraemer, H. C. & Killen, J. D. (1998). Factors associated with weight concerns in adolescents. International Journal of Eating Disorders, 24, 31-42. Winzelberg, A. J., Taylor, C. B., Sharpe, T., Eldredge, K. L., Dev, P. & Constantinou, P. S. (1998). Evaluation of a computer-mediated eating disorder intervention program. International Journal of Eating Disorders, 24, 339-349. Woodside, D. & Garfinkel, P. (1992). Age of onset of eating disorders. International Journal of Eating Disorders, 12, 31-36. Outcomes for Participants With Complete Data at Postintervention and Follow-Up
Outcomes for High-Risk Participants With Complete Data at Postintervention and Follow-Up
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