Class 10 Heppner et al. Chap 12, 18 Hogg & Deffenbacher(1988)
Hogg & Deffenbacher (1988) • Design • Independent Variables • Dependent Variables
Hogg & Deffenbacher (1988) • Design • Pre-test/post-test; experimental • Independent Variables: Categorical • Group IP Treatment • Group Cognitive Behavioral Trtmnt. • Control Group
Hogg & Deffenbacher (1988) • Dependent Variables- Continuous • BDI Depression • MMPI-D Depression • ATQ Automatic Thghts. • Coopersmith SEI Self Esteem • Therapist Assessment of Client Behavior: • one item assessment of each: depression, coping, anxiety, motivation to change, group participation
Types Outcome Studies Kazdin (chap 18) • Treatment Package Strategy • Dismantling Strategy • Constructive Strategy • Parametric Strategy (structural components) • Comparative Outcome Strategy • Client and Therapist Variation Strategy Moderation Designs
Types Outcome Studies Kazdin (chap 18) • Treatment Package Strategy • Dismantling Strategy • Constructive Strategy • Parametric Strategy (structural components) • Comparative Outcome Strategy • Client and Therapist Variation Strategy (Moderation Designs )
Types of Control Group • No – treatment • Placebo ?? • Matched
Internal/External Validity • Inclusion Criteria • Cng Center Clients • BDI>14 • Exclusion Criteria • Co-morbidity • Suicidal lethality • In therapy • Drug abuse/depend. • Internal Validity • Key issue • External Validity • Key issue
Treatment Implementation Validity • Specificity of Treatment • Therapist Training • Fidelity Checks
Treatment Validity • Treatment Specificity • CBT: emotional transactions • IPT : CB techniques for daily life • Therapist Training • Crossed by sex and theoretical orientation • Weekly supervision; rating tapes on fidelity • Fidelity Checks: • End of treatment blind raters, and • Client Evaluation of Treatment
3 X 2 Repeated Measures ANOVADep vs. Pre-test BDI & Post-Test BDI
Treatment Effect: Do the treatment groups differ in the BDI, regardless of TIME? NS
Trial Effect**: Do the Time groups differ regardless of Treatment? Time effect S*
Interaction Effect : Do the Time groups differ in the BDI, by Treatment Group? NS
Questions Addressed • Do clients assigned to CBT show lower BDI scores (Post-T and Pre-Test) than clients assigned to IPT or than clients assigned to control group? (regardless of Time) Treatment Effect- Repeated Measures • Do clients who receive CBT + IPT + no treatment show lower BDI post-test scores than pre-test BDI scores? Trial Effect – Repeated Measures
Questions Addressed • In which of the three experimental groups clients showed change in depression following treatment? Treatment x Trial Interaction – Repeated Measures • Another way: In which of the three experimental groups clients showed lower levels of depression at the end of treatment?
In which of the three groups clients showed lower levels of depression at the end of treatment (only)?Analysis ?? MANOVA or MANCOVA?
In which of the three groups clients showed lower levels of depression at the end of treatment?Analysis: MANCOVA
Specific Change Mechanisms • Expected greater early change in • IPT: Self-esteem • CBT: Automatic thoughts
Treatment-Time Changes • For the three groups -- CBT, IPT, and control group-- the magnitude of the changes from assessment time to assessment time was statistically significant and indicated lower depression. • Because the effect for all groups was the same, including the no-treatment control group –findings suggests that CBT and IPT were as effective as:
Depression Level treatment placebo MT1 F2 MT2 PrT F3 PsT F1 (Measurement Time) Profile Plots Illustrating the Question of Interest TIME*TREATMENT INTERACTION Here the effect of time is NOT the same for both groups. Thus we say that there is TIME and TREATMENT interaction.