Journal of Consulting and Cfinical Psychology Copyright 2000 by the American Psychological Association, Inc. 2000, Vol. 68, No. 4, 650-657 0022-006X/00/$5.00 DOI: 10.1037//0022-006X.68.4,650

Reducing Risk Factors for Eating Disorders: Comparison of an Internet- and a Classroom-Delivered Psychoeducational Program

Angela A. Celio and Andrew J. Winzelberg Stanford University School of Medicine

Denise E. Wilfley San Diego State University and

University of California, San Diego

Doff Eppstein-Herald San Diego State University

Elizabeth A. Springer Harvard University School of Medicine

Parvati Dev and C. Barr Taylor Stanford University School of Medicine

This controlled trial compared lnternet- (Student Bodies [SB]) and classroom-delivered (Body Traps [BT]) psychoeducational interventions for the reduction of body dissatisfaction and disordered eating behaviors/attitudes with a control condition. Participants were 76 women at a private university who were randomly assigned to SB, BT, or a wait-list control (WLC) condition. Measures of body image and eating attitudes and behaviors were measured at baseline, posttreatment, and 4-month follow-up. At posttreat- ment, participants in SB had significant reductions in weight/shape concerns and disordered eating attitudes compared with those in the WLC condition. At follow-up, disordered behaviors were also reduced. No significant effects were found between the BT and WLC conditions. An Internet-delivered intervention had a significant impact on reducing risk factors for eating disorders.

Excessive weight concerns, body image dissatisfaction, and disordered eating patterns are commonly exhibited by female college students (Bushnell, Wells, Hornblow, Oakley-Browne, & Joyce, 1990; Drewnowski, Yee, Kurth, & Krahn, 1994; Mintz & Betz, 1988). Approximately 1% to 2% of the young adult female population suffers from full syndrome bulimia nervosa (Falrburn & Beghn, 1990), and more than 10% of college women are thought to have subclinical bulimia nervosa (Drewnowski et al., 1994), defined as meeting the criteria for bulimia nervosa without the threshold frequency of binge eating. Disordered eating patterns result in serious physical consequences and are associated with loss of confidence and self-esteem, shame, and other psychological problems and disorders (Halmi, 1997; Stice, Killen, Hayward, & Taylor, 1998; Taylor et al., 1998).

Recent studies have found that excessive weight and body shape concerns are risk factors for the development of eating disorders

Angela A. Celio, Andrew J. Winzelberg, and C. Barr Taylor, Depart- ment of Psychiatry, Stanford University School of Medicine; Denise E. Wilfley, Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego; Dori Eppstein-Herald, Department of Psychology, San Diego State University; Elizabeth A. Springer, Harvard University School of Medicine; Parvati Dev, Stanford University Medical Media and Information Technologies, Stanford Uni- versity School of Medicine.

This study was supported in part by funds from the McKnight Founda- tion.

Correspondence concerning this article should be addressed to C. Barr Taylor, Department of Psychiatry, Stanford University School of Medicine, Room 1326, Stanford, California 94305-5722. Electronic mail may be sent to btaylor @ leland.stanford.edu.

(Herzog, Hopkins, & Burns, 1993; Killen, Hayward, et al., 1994; KiUen, Taylor, et al., 1994; Patton, Johnson-Sabine, Wood, Mann, & Wakeling, 1990). Excessive weight and body shape concerns consist of fear of gaining weight, worry over weight and body shape, dieting history, and perceived fatness (Killen et al., 1996). It is posited that the reduction of these concerns, and improvement in body satisfaction, will reduce the onset of eating disorders in a high-risk population (Taylor & Altman, 1997).

To prevent the development of eating disorders, educational and school-based interventions have been strongly recommended (Centers for Disease Control and Prevention, 1996; Neumark- Sztainer, 1996). Although most prevention programs designed to change attitudes and behaviors associated with disordered eating generally have not been successful (Levine, 1999), Huon (1994) and Grant and Cash (1995) both showed that interventions using cognitive-behavioral orientations reduced body image dissatisfac- tion. Further, two more recent programs have been found effective in improving body satisfaction and reducing disordered eating attitudes and behaviors in college women (Springer, Winzelberg, Perkins, & Taylor, 1999; Winzelberg et al., 1998, 2000).

In an uncontrolled study, Springer et al. (1999) found that Body Traps: Perspectives on Body Image, an educational intervention provided in an academic format, significantly improved students' body image and disordered eating habits. The other studies (Win- zelberg et al., 1998, 2000) evaluated the effectiveness of the computer-delivered program Student Bodies, a structured 8-week psychoeducational intervention based on a cognitive-behavioral approach. The intervention includes a moderated electronic dis- cussion group in which participants discuss their reaction to the software content and general topics. Both evaluations of Student

650

REDUCING RISK FACTORS FOR EATING DISORDERS 651

Bodies found that intervention participants, compared with con- trols, improved their body satisfaction and reduced their disordered eating attitudes and behaviors.

Although the results have been encouraging, the overall com- pliance rate of Student Bodies in these trials was 53% (Winzelberg et al., 1998) and 64% (Winzelberg et al., 2000). Past studies suggested that higher adherence was associated with better out- comes. Thus, to improve compliance and to extend the program's previous results, we offered an incentive of a pass/fail grade based on adherence to Student Bodies in the present study. Further changes to the Student Bodies program were made to make it more user-friendly on the basis of participant feedback and additional research (e.g., more clearly defined assignments).

The present study compared the modif ied version of Student Bodies and the academic course intervention Body Traps with a control condition. Both interventions offer a cost-effective and easily disseminated eating disorder prevention program to college students. It was hypothesized that each intervention would de- crease body dissatisfaction and disordered eating behaviors and attitudes at posttreatment and at follow-up.

Method

Participants

Participants (N = 76) were female undergraduates enrolled in a private university in noltbern California and were recruited primarily through fliers posted on campus that advertised for a study to help women improve their body image. In addition, E-mail messages were posted on campus housing distribution lists. Participants had high body dissatisfaction, as measured by baseline Body Shape Questionnaire (BSQ; Cooper, Taylor, Cooper, & Fairbum, 1987) scores (M = 109.6, SD = 30.4), compared with "normal" college students (M = 72, SD = 23).

Participants were excluded if they were currently diagnosed as bulimic or anorexic (self-report) or had a body mass index less than or equal to 17.5. After informed consent was obtained, participants were randomly assigned to one of three conditions: Student Bodies (Internet program), Body Traps (classroom program), or wait-list control (WLC). Participants assigned to the WLC condition were offered the opportunity to complete the Student Bodies intervention during the following fall quarter. Partici- pants were offered 2 units of ungraded academic credit contingent on completion of program requirements.

Descriptions of Interventions

Student Bodies (Internet program). Student Bodies is a structured 8-week psychoeducational intervention delivered primarily through the Internet. The primary goal of the program is to reduce body dissatisfaction and excessive weight concerns. The program incorporates ideas and inter- ventions from the Road to Recovery program for individuals with bulimia (Davis et al., 1989), cognitive-behavioral therapy exercises presented by Cash (1991), Fairburn and colleagues' (e.g., Falrburn & Carter, 1996; Fairburn et al., 1995) work on binge eating, and guidelines suggested by Taylor and Altman (1997) in their review of eating disorder prevention programs.

Participants were able to access the password-protected program from any computer with an Interaet connection. Every time the participants logged on, they filled out an on-line progress report and were given feedback on their level of effort and improvement. In addition, participants received weekly feedback about their adherence to the assignments by E-mail.

Each week, participants were instructed to read a series of readings on-line. These readings addressed issues such as body image dissatisfac-

tion, excessive weight concerns, dieting or restrained eating patterns, exercise, and nutrition. Each week's readings included a required cognitive-behavioral exercise (e.g., challenging negative thoughts and observing "real" women in public and comparing them to women seen in fashion magazines). Participants were also encouraged to post weekly entries in the confidential on-line body image journal. The goal of the journal was for the participants to identify the situations that trigger their negative body image and to eventually challenge their dysfunctional beliefs.

In a moderated, on-line discussion group, participants were required to post one or two responses to the on-line readings and exercises. In addition, they were asked to post at least one message each week in response to another group member's message in order to promote discussion and a supportive atmosphere. To enhance group cohesion and familiarity with the other group members, the discussion group bad a link to "profiles" of each of the group members. Each profile comprised a photograph of the partic- ipant and a personal statement introducing herself and stating her personal goals for the program.

Face-to-face sessions, lasting 1 to 2 hr, were held during the 1st, 2nd, and 6th week of the intervention. These meetings were used to orient the participants to the program and to enhance the condition's cohesion. Face-to-face sessions were led by a moderator (Angela A. Cello). The moderator also led discussions within the on-line discussion group and addressed any problems participants had with the software.

Participants were required to read one article from a course reader each week. The course reader was the same one used in the Body Traps course and included articles on body-image-related topics, such as the social and economic effects of weight stigmatization and medical effects of dieting. These readings came from a variety of sources, ranging from psychology journals to feminist-perspective books (Springer et al., 1999). The goal of these readings was to encourage the participants to consider body image and body dissatisfaction from a variety of perspectives. Participants were required to write a one-page critical reflection paper each week on a reading of their choice. These papers were sent by E-mall to the moderator.

Participants were told that they would receive pass/fall grades based on completion of the written reflection papers, number of discussion group messages posted, and number of on-line screens read. If participants did not complete an adequate number of the assignments, they would be given a failing grade.

Body Traps (classroom program). The other intervention offered was a face-to-face course called Body Traps (Springer et al., 1999). On the basis of past success of Body Traps on improving body image and reducing disordered eating habits and attitudes, the objectives of Body Traps were the same as those of Student Bodies. However, the focus of the class remained primarily academic and did not focus on cognitive, behavioral, or other methods for weight regulation or improvement in body image. Table 1 compares the basic requirements of each program. The Body Traps condition, taught by a graduate student in the School of Education, met once a week for 2 hr at a time. Every week, there was a lecture by the instructor or a guest speaker as well as a group discussion on the following topics regarding body image: the media, historical perspectives, physical disabilities, development in childhood and adolescence, eating disorders, obesity, and cultural and ethnic differences in body image. Participants were required to read two to three readings each week (from the same course reader as the Student Bodies condition) and to write a one- to two-page reflection paper discussing their personal reactions and feelings.

Similar to the Student Bodies condition, Body Traps participants were told that they needed to complete the written reflections and attend class in order to receive a passing grade in the class.

WLC. Those assigned to the WLC condition were offered the oppor- tunity to use the Student Bodies program after the follow-up assessment. Because of limited resources, no outcome data after the follow-up period were obtained on this condition.

652 CELIO ET AL.

Table 1 Weekly Program Requirements

Student Bodies Body Traps

3 face-to-face sessions (over 8-week period). Weeks 1 and 2: Orientation to program. Week 6: Group discussion on body image dissatisfaction.

Academic readings (1-2 articles/week). Written reflections in response to academic readings (1-2 pages).

On-line readings on body image, exercise, nutrition, and eating disorders; cognitive-behavioral exercises.

On-line body image journal (--> 1 entry/week [suggested]). Discussion group messages (at least 2 messages/week, 1 in

response to a group member).

Eight 2-hr class meetings (over 8-week period). Lecture or guest speaker. Group discussion.

Academic readings (1-2 articles/week). Written reflections in response to

academic readings (1-2 pages).

Measures

Primary. The primary dependent measures relating to body satisfac- tion were the Weight/Shape Concerns subscale of the Eating Disorder Examination Questionnaire (EDE-Q; Fairburn & Beglin, 1994) and the BSQ (Cooper et al., 1987). The EDE,-Q Weight/Shape Concerns subscale combines two of the original subscales (Weight and Shape), which are correlated with the corresponding subscales of the EDE at r = .79 and r = .80, respectively (Fairburn & Beglin, 1994). Internal consistency for the EDE--Q Weight/Shape Concerns subscale in the present sample was a = .92. Internal consistency, test-retest, and concurrent validity coefficients for the BSQ were a = .97, c~ = .88, and ct = .66, respectively (Rosen, Jones, Ramirez, & Waxman, 1996). For the present sample, the internal consistency for the BSQ was ct = .96. The EDE-Q was administered as a whole; thus, the Weight/Shape Concerns subscale was used to measure participants' concerns with weight/shape. The BSQ was included for comparison with past studies of Student Bodies. At baseline, the Spearman correlation between the EDE--Q Weight/Shape Concerns subscale and the BSQ was .86, suggesting that the BSQ measures the same constructs as the EDE-Q Weight/Shape Concerns subscale.

Secondary. Secondary dependent measures used to examine disor- dered eating attitudes and behaviors included the Eating Concerns and Restraint subscales of the EDE-Q and the Drive-for-Thinness and Bulimia scales on the Eating Disorder Inventory (EDI; Garner & Olmsted, 1984). The internal consistencies for these scales using the present sample were as follows: for the EDE-Q Eating Concerns subscale, a = .82; for the EDE-Q Restraint subscale, a = .82; for the EDI Drive-for-Thinness scale, c~ = .91; and for the EDI Bulimia scale, ct = .88. Rather than using the discontinuous scoring method for the EDI, which is appropriate for clinical samples (i.e., the three least symptomatic responses receiving a score of zero), the EDI was scored as a continuous measure in order to provide greater sensitivity (Schoemaker, van Strein, & van der Staak, 1994). Intervention participants completed a four-item Social Support Scale adapted from the Multidimensional Scale of Perceived Social Support (MSPSS; Winzelberg et al., 2000). Previous studies have shown the MSPSS to have good reliability (Dahlem, Zimet, & Walker, 1991). The scores from each adapted item, scaled 1 to 7, were added and then averaged. Additionally, qualitative feedback on each intervention was gathered at posttreatment.

Compliance with Student Bodies was determined by assessing the par- ticipants' percentage of assigned on-line screens read, percentage of re- quired discussion group messages, percentage of face-to-face sessions attended, and percentage of assigned written reflections submitted. These variables were combined to create a global compliance variable by calcu- lating the overall mean. Compliance to Body Traps was defined as the participants' percentage of classes attended and percentage of assigned written reflections submitted. These two variables were also combined to create a global compliance variable by calculating the overall mean.

Procedures

Participants completed baseline measures and were then randomly as- signed to one of the three conditions. Posttreatment and follow-up mea- sures were collected at 2 and 6 months.

Data Analysis

We compared baseline differences between the three conditions using an analysis of variance (ANOVA). Participants completing the study were compared with those who dropped out using an ANOVA, and differential attrition rates between the conditions were examined using a chi-square analysis. Dropouts were defined as those participants who were not avail- able for assessment at posttreatment or at follow-up.

We assessed the main effects of the intervention using one-way analyses of covariance with the baseline measure as a covariate and condition assignment as the independent measure. When condition differences were found, post hoc univariate Scheff6 confidence intervals were used to determine where the differences occurred. We also examined all of the outcome analyses using an intention-to-treat sample.

To determine if there were differential effects between the two inter- ventions for women at higher risk for developing an eating disorder, we defined high risk as scoring greater than 110 on the BSQ (Winzelberg et al., 1998, 2000). This definition was based on the work of Cooper et al. (1987), who found that individuals with bulimia scored a mean of 129 (SD = 17) on the BSQ compared with a mean of 72 (SD = 23) for college students. The cutoff for high risk was determined by taking approxi- mately 1 SD below the mean score of women with probable cases of bulimia nervosa and 1 SD above the norm for college students. Completers' scores on the primary outcome variable were examined to determine if any Risk X Assignment effects existed. This was done using a two-way ANOVA with the baseline measure as a covariate and both assignment and a dichotomous risk variable as the independent measures.

A stepwise regression was used to explore the relationship between the level of compliance for completers and their posttreatment scores on the primary outcome variables. To account for potential collinearity between preintervention symptomatology and level of compliance, we controlled for baseline scores in the first step of the analysis.

Resu l t s

Of the 76 participants who completed the basel ine measures, 27 were randomly assigned to Student Bodies, 25 to Body Traps, and 24 to the WLC condition. Sixty-seven percent of the partici- pants identified themselves as Caucasian, 11% as Afr ican Amer- ican, 9% as Asian, 7% as Hispanic/Latina, and 6% as mult iethnic

REDUCING RISK FACTORS FOR EATING DISORDERS 653

or "other." The average age of participants was 19.6 years (SD = 2.2, range = 18-36).

There were no baseline differences found between conditions in the primary or secondary outcome measures. A significant differ- ence was found in the class distribution, with the WLC condition having more freshmen and fewer sophomores than the Body Traps condition, )(2(6, N = 76) = 13.50, p = .036.

Of the 76 participants, 9 women did not complete the post- intervention assessment (1 Student Bodies, 5 Body Traps, and 3 WLC) and 9 additional women did not complete the follow-up assessment (2 Student Bodies, 5 Body Traps, and 2 WLC), result- ing in a total of 18 dropouts (3 Student Bodies, 10 Body Traps, and 5 WLC). The overall attrition rate was 24%. There were no significant differences between dropouts and nondropouts on any baseline measures. No significant differences were found between the conditions' attrition rates at posttreatment. At follow-up, a statistically significant difference in attrition was found between the Body Traps condition and the two other conditions, )(2(2, N = 76) = 6.24, p = .044.

Intervention Effects: Posttreatment

The means and standard deviations for each condition at the three assessment periods are presented in Table 2. At posttreat- ment, significant condition differences were found for the EDE-Q Weight/Shape Concerns subscale, F(2, 54) = 5.23, p = .008, and the EDI Drive-for-Thinness scale, F(2, 54) = 3.32, p = .044.

Post hoc comparisons showed that the significant differences for the EDE-Q Weight/Shape Concerns subscale and the EDI Drive- for-Thinness scale occurred only between the WLC condition and the Student Bodies condition, with the Student Bodies condition showing greater improvement.

Intervention Effects." Follow-Up

At follow-up, significant condition differences were found for the Weight/Shape Concerns subscale, F(2, 54) = 3.38, p = .042. Significant condition differences were also found for the following secondary measures: the EDE-Q Eating Concerns subscale, F(2, 54) = 3.36, p = .042; the EDE--Q Restraint subscale, F(2, 54) = 6.02, p = .004; and the EDI Drive-for-Thinness scale, F(2, 54) = 5.19, p = .009. Post hoc comparisons identified significant differ- ences occurring between the WLC condition and the Student Bodies condition, with the Student Bodies condition showing more improvement on each of these measures.

Intention-to- Treat Analysis

We also performed an intention-to-treat analysis that included all of the dropouts. If posttreatment and/or follow-up data were not available for a participant, the baseline data were carried forward. At posttreatment, significant condition differences were found on all of the primary and secondary measures (p < .05). In each post hoc comparison, the significant differences occurred between the WLC condition and the Student Bodies condition, with the Student Bodies condition showing greater improvement.

At follow-up, significant condition differences (p < .05) were found for the same measures as found in the completers' analysis (i.e., the EDE--Q Weight/Shape Concerns, Eating Concerns, and

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Restraint subscales and the EDI Drive-for-Thinness scale). Post hoc analyses revealed that the Student Bodies condition showed a significantly greater improvement than the WLC condition in each of these comparisons.

Intervention Effects: High-Risk Condition

To explore the possibility that treatment effects might differ by a participant's high-risk status, we performed a two-way ANOVA on the completers' primary outcome measures with assignment and risk level as independent variables. An Assignment x Risk interaction was found on the EDE-Q Weight/Shape Concerns subscale at posttreatment, F(2, 51) = 5.40, p = .007, but not at follow-up. As illustrated in Figure 1, Student Bodies was more effective than Body Traps and the WLC condition in reducing weight/shape concerns in high-risk participants. Significant inter- actions were also found on the BSQ at posttreatment, F(2, 51) = 5.16, p = .009, and at follow-up, F(1, 51) = 3.98, p = .025, with post hoc comparisons revealing greater improvement in the

Student Bodies condition as compared with the Body Traps condition.

Intervention Effect Sizes

We calculated intervention effect sizes by taking the change scores for each outcome measure for the two interventions be- tween baseline and posttreatment, subtracting the change scores for the WLC condition, and dividing this difference by the pooled standard deviation of the chosen measure at baseline (Cohen, 1988). The same calculation was done for the baseline-to- follow-up period. The results are displayed in Table 3.

To compare Student Bodies with other previously studied inter- ventions, we used a slightly different method of calculating effect size (Rosen, Orosan, & Reiter, 1995). These effect sizes were calculated as the baseline mean minus the posttreatment mean, divided by the baseline standard deviation. In examining the BSQ, a measure of body image also used by many other studies of body image interventions, we found that the effect size of Student Bodies was 0.92.

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Figure 1, Change in EDE-Q Weight/Shape Concerns subscale for participants who completed assessments at all three data points. EDE-Q = Eating Disorder Examination Questionnaire; WLC = wait-list control; BT = Body Traps (class); SB = Student Bodies (Internet).

REDUCING RISK FACTORS FOR EATING DISORDERS 655

Table 3 Effect Sizes

Baseline to posttreatment Baseline to follow-up

Body Traps Student Bodies Body Traps Student Bodies Measure vs. WLC vs. WLC vs. WLC vs. WLC

BSQ 0.07 0.35 0.30 0.22 EDE--Q

Weight/Shape Concerns 0.14 0.56 0.14 0.56 Eating Concerns -0.18 0.30 -0.08 0.44 Restraint 0.14 0.48 0.34 0.69

EDI Bulimia 0.09 0.34 -0.03 0.30 Drive-for-Thinness 0.16 0.40 0.19 0.66

Note. WLC = wait-list control; BSQ = Body Shape Questionnaire; EDE--Q = Eating Disorder Examination Questionnaire; EDI = Eating Disorder Inventory.

Compliance

On average, among completers, the Student Bodies participants read 71% of the assigned on-line screens and posted 64% of required discussion group messages. Compliance with the discus- sion group was higher in the early weeks of the program, with postings becoming less frequent over time. On average, partici- pants submitted 74% of the required written reflections and at- tended 63% of the face-to-face sessions. Using a global variable of compliance, participants in Student Bodies completed 68% of all assigned activities.

Average attendance in the Body Traps class was 59%. On average, participants submitted 55% of the required written reflec- tions. Using a global variable of compliance, we found that par- ticipants in Body Traps completed 57% of all assigned activities.

To determine how compliance contributed to the primary out- come measures at posttreatment, we performed a multiple regres- sion analysis, forcing baseline scores in first. After accounting for baseline differences, we found that compliance contributed an additional 13% to the explained variance for the posttreatment EDE--Q Weight/Shape Concerns subscale and 11% to the ex- plained variance for the posttreatment BSQ in the Student Bodies condition. Higher compliance was associated with greater im- provement. In the same analysis for the Body Traps condition, compliance explained less than 1% of the variance in outcome for the posttreatment EDE-Q Weight/Shape Concerns subscale and the BSQ.

Social Support

At posttreatment, completers in the Student Bodies (M = 4.79, SD = 1.1) and Body Traps (M = 4.77, SD = 1.6) conditions reported receiving a moderate amount of social support from the other participants in their conditions. An independent samples t test revealed no significant differences between the two conditions. Posttreatment perceptions of social support from other participants were not significantly correlated with the percentage of classes attended in the Body Traps condition. In the Student Bodies condition, the percentage of required discussion group messages that were posted was significantly correlated with perception of social support (r = .64, p = .002).

Discussion

This study demonstrated that an Internet-based program, Stu- dent Bodies, was effective in reducing body image dissatisfaction and disordered eating attitudes and behaviors in college-age women. The strongest results occurred at follow-up, with signifi- cant improvement seen on most of the dependent measures. The psychoeducational class, Body Traps, produced no significant ef- fects on any measures in comparison with a WLC condition. Intention-to-treat analyses were also performed and revealed im- provement on all of the measures for the Student Bodies condition at posttreatment and most of the measures at follow-up. These intention-to-treat results must be interpreted with particular cau- tion given the differential attrition rates and, consequently, the greater amount of imputed data between the Body Traps and the other two conditions.

The treatment effect size of Student Bodies on many of the measures was promising. The strongest effect sizes in either time period were found for the EDE-Q Weight/Shape Concerns sub- scale, the EDE-Q Restraint subscale, and the EDI Drive-for- Thinness scale (range = 0.40-0.69). Using Rosen et al.'s (1995) effect size calculation for comparison with past studies, we found that the effect size of Student Bodies on the BSQ was 0.92. This effect size is comparable with the interventions from which Stu- dent Bodies was developed, whose effect sizes ranged from 0.8 to 1.5, depending on the study (Grant & Cash, 1995; Rosen et al., 1995; Rosen, Saltzberg, & Srebnik, 1989).

Changes made to this most recent version of Student Bodies to improve compliance appear to have resulted in some success. In the ftrst version of the program, participants self-reported reading only 53% of the program's screens (Winzelberg et al., 1998). More recently, participants read an average of 64% of assigned on-line screens (Winzelberg et al., 2000). Using the same measures, the present study resulted in a compliance rate of 71%. Similar to previous findings (Winzelberg et al., 2000), the present results showed that higher compliance to the program requirements was associated with greater improvement on both primary outcome measures.

As with all Internet-based conditions, issues of privacy and confidentiality are of concern. In the present study, measures were

656 CELIO ET AL.

taken to protect the participants' identity from nonparticipants (e.g., a password was required to log on). However, participants' photographs were posted on the discussion group page, eliminating confidentiality within the condition. Despite the lack of within- condition anonymity, participants gave generally positive qualita- tive feedback regarding the use of their pictures, citing that seeing what the other condition members looked like made them more "real" and facilitated on-line interactions.

The results of the Body Traps intervention were not found to be statistically significant compared with the WLC condition. The treatment effect size of Body Traps, using Rosen et al.'s (1995) calculation method, was 0,61 for the BSQ, which exceeds that of the first study of Body Traps, for which the effect size was 0.36 (Springer et al., 1999).

The dropout rate in the Body Traps intervention was higher than expected. Analyses revealed a statistically significant difference in attrition between the Body Traps condition and the two other conditions at follow-up, with a higher number of participants from the Body Traps condition dropping out. In the previous study of Body Traps (Springer et al., 1999), there were no dropouts. The differences in dropouts between the Body Traps trials may be explained, in part, by study design. In Springer et al.'s study, participants filled out an application to be a part of the class, which included writing a short essay on the reasons for taking the class, resulting in a very motivated and compliant condition. The present study followed a randomized design in which women less inter- ested in this intervention might have been assigned to Body Traps, possibly contributing to a higher dropout rate.

The Student Bodies intervention required greater personal in- volvement from its participants compared with the Body Traps class, and this greater involvement may have contributed to Stu- dent Bodies' positive outcomes. However, even with the less extensive demands made on the Body Traps condition, the Body Traps participants' compliance rates were lower than those of the Student Bodies participants. It may have been easier to be com- pliant to the Student Bodies intervention because of its delivery method. Because it was offered through the Internet, participants could meet the program requirements at any time of day or night throughout the week. In contrast, Body Traps participants had only one chance each week to attend class, making it more difficult to comply with the intervention.

In addition to availability, Internet conditions have the added advantage of automatically collecting adherence/participation data. Furthermore, using the computer as a medium allows moderators to monitor the content of both the discussion group messages and the personal body image journals for indications that a participant needs help beyond that which is provided in the program.

Of note, to our knowledge, this is the first study to show that an on-line discussion group with limited face-to-face contact pro- duces a similar level of perceived support as a purely face-to-face condition, despite the large difference in the amount of time spent in person. In the Student Bodies condition, greater use of the electronic discussion group, in particular, had a positive relation- ship with higher ratings of social support, suggesting that the support may have been derived from interaction through a com- puter rather than in person. This finding demonstrates the potential for commensurate levels of social support within Internet condi- tions that are supplemented by brief face-to-face contact as com- pared with purely face-to-face conditions.

Our findings suggest that an Internet intervention with limited face-to-face contact was more effective in improving body image and reducing disordered attitudes and behaviors than a purely face-to-face psychoeducational intervention. However, the high dropout rate in the face-to-face condition may have affected the outcome. These findings need to be replicated with a larger num- ber of participants and more diverse students who are followed for a much longer period of time. If statistically significant risk- reduction effects are replicated, then it could be determined whether an intervention like Student Bodies could actually prevent the onset of eating disorders in high-risk students.

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Received July 22, 1999 Revision received December 3, 1999

Accepted January 24, 2000