OverviewI. Process vs. Outcome DistinctionA. Process – describing events within sessions associated with changeII. Measuring Process Variables
B. Outcome --effectiveness of therapy (TX ): A pre- post-changeA. Measures of change in--
III. Measuring OutcomesB. Compliance with model
- Aspects of client verbalizations
- Depth of emotion
- Therapist interventions and consequences therefrom
- Did therapist do X, Y, or Z as stated in the treatment manual?
- Someone rates session for therapist behaviors
A. Pre-, Post-, Follow-up
- Controlling for repeated measures?
- Intervening "treatments"?
- Deterioration effect (does anyone get worse?)
C. Ecological or External validity
Who's responsibility is it to show
that the skills taught in treatment
ARE effective (i.e., the right ones)
for bringing about a better
relationship ?
D. Sources of information
From whom do we get reports
of improvement?
Clients, Therapist (?), Outsiders
Review your "Consumer’s
Guide to Evaluating Therapy Studies"
VI. Assessing Outcome Reliability
C. Calculating Effect Size
Based on area under the
normal probability curve, use the formula:
I. Making Pre- Post- Comparisons
B. Real Change vs. Noise
Depends upon the Reliability
of the Measure
C.When is a Measure reliable?
E. All of this is to get to this point: we want
to express outcome success of
individuals. How many people
in the treatment group showed significant
improvement? Improvement over what?
Where they started from;
how much is significant? If their
change score is divided by the SE of the
measure (e.g., DAS) we can
determine whether they changed significantly.
Reliable Change Index = RC = Post - Pre
SE
Note:
SE in this case is the standard error of measurement, which is
estimated by the equation
where rxx =
the reliability of the test, and SD = the sigma of test mean.
The change is relative to error units! We can now count
the percentage
of people
who improved significantly.
F. Clinical vs. Statistical Significance
It is possible to
show statistically significant change based on the R-C score,
but this may be
different from
clinically significant change. A person (couple)
may move from a
low DAS score of 75 to 85, pre- to post-therapy. But 85 on
the DAS is still within
the distressed range for that test!
G. Also note that we have the option of reporting
individual spouse scores
or
couple scores. Couple scores would be the avergae of each person's
score. But
what to do when one person is 85 and the other is 110? Is the
average meaningful
in this case since it yields a score of 97.5, which is
almost "normal"
although one person is clearly distressed.
I. Alternatives to Control Groups
A. Treatment on demand (TOD): control over control group
B. Minimal contact agreements
C. Non-specific controls
II. Ethical Issues in Marital Therapy (AAMFT Ethics)
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