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Class 11 -12

Class 11 -12. Chapters 5 & Elkins (1989). Elkin et al: Purpose. Test feasibility of the collaborative clinical trial model Examine relative efficacy of CBT, IPT , and Medication for Depression. NIMH Treatment of Depression Collaborative Research Program. U. of Pittsburg

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Class 11 -12

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  1. Class 11 -12 Chapters 5 & Elkins (1989)

  2. Elkin et al: Purpose • Test feasibility of the collaborative clinical trial model • Examine relative efficacy of CBT, IPT, and Medication for Depression

  3. NIMH Treatment of Depression Collaborative Research Program • U. of Pittsburg • George Washington U. • U. of Oklahoma • 250 Patients: Major depressive disorder • 28 therapists: years experience 2 -27; 71% male • 10 psychologists • 18 psychiatrists

  4. Experimental Between-Group Designs • Post-Test Only Control • Pre-Test -- Post-Test Control • Solomon Four Group (combination of 1 and 2 above) • Factorial Design • more than one independent variable; interactions treatment X therapist or patient characteristic • Dependent Sample Design (Matching)

  5. Experimental Between-Group Designs • Post-Test Only Control • Pre-Test -- Post-Test Control • Solomon Four Group (combination of 1 and 2 above) • Factorial Design - Post Hoc • more than one independent variable; interactions • treatment X patient characteristic (depression level at intake) • Dependent Sample Design (Matching)

  6. IVs: Experimental Groups: Cognitive Behavioral Therapy Interpersonal Therapy 16 individual sessions/ 50 min. Medication+ Clinical Management* Pill-Placebo+ Clinical Management* 1st session 55 min.; then 20 to 25 min. * Minimal supportive therapy condition 6

  7. Dependent Variables

  8. Dependent Variables

  9. Outcome Research Strategies • Primary Analyses • Secondary Analyses (Post-Hoc)

  10. Outcome Research Strategies • Primary Analyses • Treatment package • Comparative • Secondary Analyses • Client Variation-moderation effect?

  11. Outcome Research Strategies • Secondary Analyses • Client Variation-moderation effect depression level at intake as moderator of relation of treatment groups to outcome Were outcomes across treatment types different for patients with higher versus lower levels of depression at pre-test?

  12. Control Groups • CBT • IPT • Medication+ Clinical Management* • Pill- Placebo+ Clinical Management* * Minimal supportive therapy condition

  13. Treatments & Therapists

  14. Ensure Valid Treatments • Specify the treatment(s) • Therapist training/monitoring • Fidelity Checks

  15. Ensure Valid Treatments • Specify the treatment(s) • Manuals • Therapist training/monitoring • Fidelity Checks- therapy tapes • Collaborative Study Psychotherapy Rating Scale (CSPRS) • Treatments could be discriminated 95% of the time

  16. Attrition (>15 sessions or 12 weeks)

  17. Which group to use in outcome analysis??

  18. Assessment Times • Pre treatment • Post Treatment • 4, 8, 12 weeks • Termination – 15 weeks • Follow up: 6, 12, 18 months

  19. Analyses of Pre-test/Post-test (1) • Paired T-Test to examine differences between pre-test and post-test scores (p. 974) • How Many ??

  20. Table 1 Completer Group: At least 12 sessions; n=155 (page 975)

  21. Analyses of Pre-test/Post-test (1) • Paired T-Test to examine differences between pre-test and post-test scores (p. 974) • How Many ?? 4 Treatment groups X 4Outcome measures CBT HRSD IPT GAS IMI-CM BDI Pla-CM HSCL-90 X 3 Samples – Completers; End Point 204; 239

  22. Findings – T-Tests

  23. Analyses of Post-test scores • Use pre-test as a covariate in analyses of co-variance to compare mean post-test scores across the 4 treatment groups • Calculate a residualized change scores – amount of variability in the post-test that is not associated with the pre-test score • Used a P<.10 in ANCOVAS and p = .10/.06 = .017 for pair-wise comparisons (p.974)

  24. ANCOVAS: Post test scores • Statistically significant differences between groups in scales at post-test • Four 3 X 4 ANCOVAS: differences across treatments in Post-treatment scoresin: HRSD, GAS--- BDI, HSCL90 • 3 (sites) X 4 (treatment groups) • Analyses reported only for treatment groups combining them across sites

  25. Co-Variates • Pre-test scores • Marriage Status (1,2) • Why not MANCOVAS? P.973

  26. Table 1 Completer Group: At least 12 sessions; n=155 (page 975) p<.10

  27. Table 1 End Point 239 Group CBT IPT IMI-CM PLA-CM p<.10

  28. Findings Pair-wise Comparisons

  29. Measuring Change Elkin et al. 1989 • Statistical significance • Clinical significance

  30. Measuring Change Elkin et al. 1989 • Statistical significance • Differences between groups in scales at post-test controlling for pre-test scores • Clinical significance • Percentage of participants that changed from dysfunctional to functional level (using cut-off scores)

  31. Clinical Significance • Recovery Analysis • Proportion of patients who improved vs. not improved • Cut Off Scores • Not Depressed HRSD < 6 and BDI < 9 • Depressed HRSD >6 or BDI > 9 • Statistical Analyses • Chi square: Proportion of depressed and non-depressed patients across treatment groups at termination.

  32. End Point 239 HRSD p = .04CBT IPTIMI-CMP-CM • Chi Square (Χ2) tests to what extent the proportion in each group is what may be expected by chance or if it is larger or smaller than expected……. • IPT = IMI-CM>Placebo-CM • CBT - % comparison was not sig. for any group

  33. Secondary Analyses • To examine effect of pre-treatment severity (HRSD/GAS) on outcome by treatment group • DVs: Post-treatment scores • Severity Criteria • HRSD>20 44% of sample • GAS<50 41% • Covariate Marital Status

  34. 2X4 ANCOVA (severity x treatment) DVs- Post TestHRSD, GAS, BDI, HSCL-90 • Main Effect for • Main Effect for • (Interaction term)***

  35. 2X4 ANCOVA (severity x treatment) DVs- Post TestHRSD, GAS, BDI, HSCL-90 • Main Effect for Severity • More Severe Pre-Test HRSD>20; GAS<50 • Less Severe Pre-Test • Main Effect for Treatment • CBT • IPT • IMI-CM • P-CM • Severity X Treatment(interaction term)*******

  36. Interaction Effect HRSD Severity x TGDependent Variables: HRSD* GAS, BDI, HSCL-90 (p.976)

  37. Interaction EffectGAS Severity x TG: Dependent Variables: HRSDGAS,BDI, HSCL-90

  38. Treatment by Severity Interaction/end-point 204 sampleHigher score Negative OutcomeHigher Score Positive Outcome

  39. Summary All Pairwise analyses following interaction effects p.976 • Less severe groups: no differences across treatment groups • More severegroups • IPTmore effective than PLA-CM in 3 instances all in the HRSDmeasure in the END Point Sample 204 (3 out of 4 comparisons) • IMI-CM more effective thanPLA-CM across a number of measures (8 out 10 comparisons)

  40. Figure 2Recovery Rates (%) endpoint /204 sample

  41. Figure 2 Recovery Rates (%) endpoint /204 sample for severity groups (p.977) • Less severe subgroups: NS differences among treatments for all samples with HRSD or GAS. • More severe subgroups for HRSD and GAS: • Consistent findings across the three samples • IPT>PLA-CM 5/6 and IMI-CM>PLA-CM 6/6

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