PSYC 3690 Chapter Notes -Binge Eating Disorder, Bulimia Nervosa, Eating Disorder

10 views8 pages
Published on 14 Apr 2013
School
University of Guelph
Department
Psychology
Course
PSYC 3690
Article #: 7
Title: Testing Mediators of Intervention Effects in Randomized
Controlled Trials: An Evaluation of Two Eating Disorder Prevention
Programs
Goals
- of the article: investigate mediators hypothesized to account for effects of 2 eating
disorder prevention programs
- the goal of the first prevention program was to reduce their thin-ideal internalization to
decrease eating disorder risk factors and bulimic symptoms
- the goal of the second prevention program was to promotes lasting healthy changes to
dietary intake and physical activity as a way of achieving a healthy body weight and
body satisfaction which decreases eating disorder risk factors and symptoms
Who Benefits? (Target Audience)
- students who have body image concerns
Universal, Selective, or Indicated
- Indicated because students had to endorse body image concerns during a telephone
screen
- each was screened and found to be at risk
Primary, Secondary, Tertiary
- primary - none of the girls already had an established disorder
Risk and Protective Factors
- risk = body image concerns
Measures of Data Collection (what is measured, # of times, and how)
- data was collected 4 times once per week for 4 weeks, tested mediation
- thin-ideal internalization was measured with an eight-item Ideal-Body Stereotype
Scale-Revised
- health eating was measured by 4 items assessing healthy eating behaviours
Intervention Strategies?
- dissonance-based program = voluntarily engage in verbal, written and behavioural
exercises in which they critiqued the thin ideal
- health weight management program = encouraged to make healthy and lasting
changes to their diet and physical activity level as a way of balancing their energy
needs with energy intake and thereby achieving a healthier weight satisfaction
Results (what did the program accomplish)
- dissonance improved body dissatisfaction, reduced negative affect and bulimic
symptoms
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in
- health weight produced reductions in body dissatisfaction, dieting, negative affect and
bulimic symptoms
Limitations
- reliance on self-report data might have been biased
- limited data on the reliability and validity of healthy eating and physical activity
measures
- design does not permit us to definitively rule out the possibility of bidirectional effects
between change in the mediators and change in the outcomes
- did not assess nonspecific factors that may partially account for intervention effects
Other Important Facts
3 Box Model: Dissonance
Dissonance-Based Model
- reductions in thin-ideal
internalization
- improved body
dissatisfaction, reduced
negative affect and
bulimic symptoms
3 Box Model: Healthy Weight Management
Healthy Weight Model
- improvements in healthy
eating and physical
activity
- reductions in body
dissatisfaction, dieting,
negative affect and
bulimic symptoms
Monday, Jan 21, 2012
7. Testing Mediators of Intervention Effects in Randomized
Controlled Trials: An Evaluation of Two Eating Disorder
Prevention Programs
Abstract
- the authors investigated mediators hypothesized to account for the effects of 2 eating
disorder prevention programs using data from 355 adolescent girls who were
randomized to a dissonance or a healthy weight intervention or an active control
condition
- the dissonance intervention produced significant reductions in out comes (body
dissatisfaction, dieting, negative affect) and the mediator (thin-ideal internalization),
change in the mediator correlated with change in outcomes and usually occurred
before change in outcomes, and intervention effects became significantly weaker
when change in the mediator was patrolled, providing support for the hypothesized
mediators and this new approach to testing mediation in randomized trials
- findings provide somewhat less support of the hypothesis that change in healthy
eating and exercise would mediate the healthy weight intervention effects
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in
- 10% of adolescent girls experience threshold or subthreshold eating disorders
- only 6 prevention programs have produced significant reductions in current or future
symptoms and only 2 produced effects that replicated across labs
- the first intention is a dissonance-based program, in which at-risk girls with body image
concerns who have internalized the thin ideal voluntarily engage in verbal, written and
behavioural exercises in which they critique this ideal
- this results in psychological discomfort that motivates them to reduce their thin-ideal
internalization to restore cognitive consistency
- results in significantly greater reductions in thin-ideal internalization, body
dissatisfaction, negative affect and bulimic symptoms
- the second intervention is a health weight management program, which promotes
lasting healthy changes to dietary intake and physical activity as a way of achieving a
healthy body weight and body satisfaction among at-risk girls with body image
concerns
- produces reductions in body dissatisfaction, dieting, negative affect, and bulimic
symptoms
- both have targeted at-risk girls because selected prevention programs tend to produce
larger effects than universal programs
- this study initiated a large efficacy trial of these 2 intentions and addressed limitations
- (a) compared our interventions with an active control intervention to rule out the
possibility that intervention effects were due to demand characteristics, expectancies,
or attention, (b) used blinded diagnostic interviews to assess eating pathology, c(c)
used long-term follow-up and (d) used a larger and more ethnically diverse sample
relative to prior trials
- 481 adolescent girls were randomly assigned to the dissonance intervention, the
healthy weight intervention, an expressive writing active control condition, or an
assessment-only control condition
- the dissonance participants showed greater reductions in eating disorder risk factors
and bulimic symptoms
- healthy weight participants showed greater reductions in these outcomes than
expressive writing and assessment-only participants
- participants in both interventions also showed lower binge eating and obesity onset
and decreased mental health service utilization
- report seeks to test hypotheses regarding the mediators that theoretically account for
the intervention effects
- mediation analyses provide a test of the mechanisms that putatively underlie
intervention effects
- test whether the mediators that are theoretically specific to an intervention account for
the intervention effects
- a previous study found that a change in body dissatisfaction partially mediated the
effects of the intervention on change in depressive and bulimic symptoms
- hypothesis: reductions in thin-ideal internalization would mediate the effects of the
dissonance intervention, vs the expressive writing control condition, on reductions in
body dissatisfaction, dieting, negative affect and bulimic symptoms
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Title: testing mediators of intervention effects in randomized. Controlled trials: an evaluation of two eating disorder prevention. Of the article: investigate mediators hypothesized to account for effects of 2 eating disorder prevention programs. The goal of the rst prevention program was to reduce their thin-ideal internalization to decrease eating disorder risk factors and bulimic symptoms. Indicated because students had to endorse body image concerns during a telephone screen. Each was screened and found to be at risk. Primary - none of the girls already had an established disorder. Measures of data collection (what is measured, # of times, and how) Data was collected 4 times once per week for 4 weeks, tested mediation. Thin-ideal internalization was measured with an eight-item ideal-body stereotype. Health eating was measured by 4 items assessing healthy eating behaviours. Dissonance-based program = voluntarily engage in verbal, written and behavioural exercises in which they critiqued the thin ideal.

Get OneClass Grade+

Unlimited access to all notes and study guides.

YearlyMost Popular
75% OFF
$9.98/m
Monthly
$39.98/m
Single doc
$39.98

or

You will be charged $119.76 upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.