Transcript Gender Differences in Treatment Response for Individuals

High Intensity Comparators:
Active Psychotherapy
Denise E. Wilfley, Andrea E. Kass, & Rachel P. Kolko
Department of Psychiatry
Washington University School of Medicine
Friday, June 24th, 2011
R29MH051384; R01MH064153; K24MH070446; T32HL00745626
Disclosures
• Research Support
– Shire Pharmaceuticals
• Advisory/Consultant
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GlaxoSmithKline Consumer Healthcare
Minnesota Obesity Consortium
United Health Group, Childhood Obesity Initiative
Wellspring Healthy Living Academy
Competing Treatments:
Going Head to Head
Overview
• Present an evolution of treatment research
evaluating high-intensity, active comparators
in contrast to IPT in the treatment of binge
eating
Rationale for Selecting an
Active Comparator
• To contrast two or more conceptually-competing
interventions
• To evaluate the varied effects of different treatments
– Short- and long-term efficacy
• To examine moderators and mediators of treatment
outcome
RCT #1: Initial Efficacy Study
Comparison of IPT, CBT, and WL Control
• Investigate whether IPT is as effective as CBT (“goldstandard”) for the treatment of recurrent binge eating
• Distinguish specificity between two models of symptom
maintenance
• Test the applicability of results from a separate study team
(Fairburn et al., 1991) in a different population
• Design: 56 women randomized to IPT, CBT, or WL control
Wilfley et al. (1993 ), J Clin Consult Psychiatry
Comparison of IPT, CBT, and
WL Control: Results
• Results support the efficacy
of IPT for binge eating
• No differential active
treatment effects
• Similar to previous findings
(Fairburn et al., 1991)
WL vs. CBT: d = 0.82
WL vs. IPT: d = 1.47
CBT vs. IPT: d = 0.38
Group X Time Interaction: p<0.003
Wilfley et al. (1993 ), J Clin Consult Psychiatry
Lingering Questions from the
Initial Efficacy Comparison Trial
• Is equivalency due to weak power (small
sample size)?
• Were the assessment measures unreliable?
RCT #2: Large-Scale Comparison of
IPT and CBT
• Compare short and long-term treatment effectiveness within
a large sample (N=162) using state-of-the-art measures
– Evaluate both treatment effectiveness and scope of outcome effects
• Assess mode specificity
– Identify mechanisms of effect and predictors of outcome
– Examine time course of changes in outcome
– Will lead to more efficient and effective treatments and provide
information about treatment matching
• Evaluate reliability of prior findings (Wilfley et al., 1993)
Wilfley et al. (2002), Arch Gen Psychiatry
Large-Scale Comparison of IPT and CBT:
Design Considerations
• Theory and empirical findings suggest IPT and CBT are ideal for
comparison  ensure specificity of effects
– Differ markedly on specific aspects (i.e., theories, assumptions, and
procedures)
– Comparable on many nonspecific elements (e.g., credibility to
patients, duration, therapist attention)
• No WL control condition
– CBT and IPT have demonstrated superiority to WL condition
– No scientific, ethical, or clinical reason to include
• No placebo psychotherapy condition
– Sufficient power to detect differences between CBT and IPT; less cost
to implement
Wilfley et al. (2002), Arch Gen Psychiatry
RCT #2: Large-Scale Comparison of
IPT and CBT
• Recovery rates:
– Equivalent
• Specificity of effects:
– Differential time course for
reductions in dietary restraint
• Treatment integrity:
– 100% rater accuracy for modality
– Significantly differentiated
treatment-specific indices
• Patient confidence in treatment:
– Equivalent
• Dropout, compliance, or
completion of follow-up:
Wilfley et al. (2002), Arch Gen Psychiatry
– Equivalent
RCT #3: Comparison of
IPT, BWL, and CBT-GSH
• Research Question: Do patients with BED require
specialty treatments?
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Investigate the long-term effectiveness of three treatments for BED
Test differential efficacy across levels of negative affect (moderator)
Examine mechanisms of therapeutic change
Assess therapist and therapy variables
• Design: 205 women and men across three sites
– Includes largest sample size to date, valid measurement of binge
eating, and long-term follow-up
– Evaluates generalizability by testing across sites
Wilson, Wilfley, Agras, & Bryson (2010), Arch Gen Psychiatry
Rationale for the Treatment Approaches
• IPT: Specialty treatment
– Addresses negative affect (moderator analysis)
– May be highly acceptable to the majority of practicing therapists
• BWL: Nonspecialty treatment
– Does not specifically target binge eating
– More easily disseminable than IPT; requires less intensive training
and therapeutic expertise
• CBT-GSH: Minimal treatment effectiveness comparison
– Controls for many of the nonspecific influences that affect outcome
– Less costly and more disseminable than BWL
Wilson, Wilfley, Agras, & Bryson (2010), Arch Gen Psychiatry
Differential Treatment Outcomes for
Dietary Restraint
F(1,193) = 5.3 p=.006 BWL > GSH
Wilson, Wilfley, Agras, & Bryson (2010), Arch Gen Psychiatry
RCT #3: Comparison of
IPT, BWL, and CBT-GSH
• Recovery rates:
– IPT and CBT-GSH > BWL
• Patient report of suitability:
– IPT significantly more suitable
• Dropout:
– IPT significantly lower rate
• Treatment Allegiances:*
BWL vs. CBT-GSH: OR = 2.3*
BWL vs. IPT: OR = 2.6*
CBT-GSH vs. IPT: OR = 1.2
*p<0.05
– No evidence of “allegiance bias” – no
differential site X treatment effects
– No individual therapist effects emerged
in IPT or CBT-GSH
Wilson, Wilfley, Agras, & Bryson (2010), Arch Gen Psychiatry
*Wilson, Wilfley, Agras, & Bryson (2011), Clin Psychol Sci Prac
Moderators at 2-year Follow-up
• Global EDE, W(1) = 4.4, p < .036
• Self-esteem, W(1) = 4.6, p < 0.032
Wilson, Wilfley, Agras, & Bryson (2010), Arch Gen Psychiatry
Remission Rates: Low Self-Esteem
and Global Eating Pathology
Percent Remission
80
70
60
50
Low EDE
40
High EDE
30
20
10
0
BWL
GSH
IPT
Wilson, Wilfley, Agras, & Bryson (2010), Arch Gen Psychiatry
Summary
• IPT is an efficacious treatment for binge eating disorder
• Using high-intensity comparators demonstrates
treatment efficacy
– Enhances ability to detect treatment matching and specificity
of effects
• Important considerations:
– Interpretation of effect sizes: likely to yield minimal differences
– Rests on strict adherence to protocol
Future Directions
• Design considerations:
– Tests of non-inferiority, equivalence, and superiority
– Patient-centered outcome research
• Assessing for patient preference and satisfaction throughout
treatment research process
• Dissemination and implementation science research