Part B3. Reading the Literature (4 points each, Total = 32 points)

Excerpt source: Kush, F. R., & Fleming, L. M. (2000). An innovative approach to short-term group cognitive therapy in the combined treatment of anxiety and depression. Group Dynamics: Theory, Research, and Practice, 4, 176-183.

Full text available here.

Twenty-nine adult psychiatric outpatients constituted the sample. They completed a 12-session group cognitive therapy program [in small groups]. Group sizes ranged from 3 to 6 members.

The instruments used in this program included the Beck Depression Inventory (BDI)..., [which] is a widely used instrumented in the evaluation of depression...Anxiety was measured with the Beck Anxiety Inventory (BAI), a 21-item self-report instrument that measures anxiety severity for the past week, including the day of completion. The Dysfunctional Attitudes Scale (DAS)....measures identification with attitudes associated with depressive disorders....

From the pre- to posttest, the average change on the BDI was a decrease of 8.42 points....BAI scores fell an average of 4.65 points.... For the DAS, the average change from pre- to posttest was 21.43 points. [The 95% confidence intervals for these mean change scores are given in Table 1.]

Table 1

Means and Standard Deviations for Outcome Measures

Pretest Posttest

Measure M SD M SD 95% CI

BDI 21.69 10.12 13.27 9.27 4.59-12.25

BAI 17.23 11.55 12.58 9.56 0.17-9.14

DAS 156.81 33.72 135.38 35.93 6.46-36.39

Note. N = 29. CI = Confidence interval; BDI = Beck Depression Inventory; BAI = Beck Anxiety Inventory; DAS = Dysfunctional Attitudes Scale.

Based on the excerpt provided, answer the following questions:

1. The anxiety scores fell an average of how many points from pretest to posttest?
   1. 4.65 points

2. For your answer to Question 1 (the point estimate), what is the 95% confidence interval (the interval estimate)? (Hint: View this video about interpreting confidence levels)

3. If you were reporting a point estimate for the mean change on the "DAS," what value or values should you report?

4. If you were reporting an interval estimate for the mean change on the "BDI," what value or values should you report?

5. For which measure does the interval estimate come closest to indicating zero change? Explain the basis of your answer.

6. Which confidence interval is the largest?

7. Which confidence interval is the smallest?

8. In light of the 95% confidence intervals, does the treatment appear to be effective? Explain.