Transcript powerpoint slides

How Effective are Behaviour
Change Interventions?
Contents:
1. How do we measure effectiveness?
2. How effective is medical therapy?
3. How effective are psychological therapies?
“Effect Size”
• A standardized statistic to show the impact of
treatments
• (Mean result for treatment group – mean for
controls) / standard deviation
Interpretation:
• An effect size of 0.5 represents a success rate of
65% in the treatment group, and 35% in the
control group (“success” = score above overall
median)
• An effect size of 0.2 suggests 55% versus 45%
Effect Sizes for Selected Medical Interventions
Intervention
Bypass graft surgery
ECT
AZT for AIDS
Drug treatment for hyperactivity
Drug treatment for arthritis
Dipyridamole
Aortocoronary bypass surgery
Drug therapy for hypertension
Chemotherapy for breast cancer
Mean
Outcome
effect size
angina
0.80
depression
0.80
mortality
0.47
behavior
0.47 to 0.96
pain, QoL
0.45 to 0.77
angina
0.24
mortality
0.15
quality of life 0.11 to 0.28
mortality
0.08 to 0.11
How Effective are Psychological &
Behavioral Treatments?
Intervention
General Psychotherapy
Behaviour Modification
# studies
mean
effect size
1231
953
0.79
0.53
Family & Marital Counselling
Treating Juvenile Delinquents
Meditation & Relaxation
295
871
289
0.55
0.29
0.54
Biofeedback & Relaxation
Smoking Cessation
Psychological Treatment for Pain
109
125
219
0.65
0.55
0.90
Source: Lipsey MW, Wilson DB. The efficacy of psychological, educational,
and behavioral treatment. American Psychologist 1993;48:1181-1209.