Table 2.
Pre-post effect sizes based on different values for the correlations between pre-test and post-test
| HAMD (N = 14) | BDI (N = 9) | BDI-II (N = 5) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| SMD | 95% CI | ∆SMD | SMD | 95% CI | ∆SMD | SMD | 95% CI | ∆SMD | ||
| True effect size based on exact correlations | ||||||||||
| CBT | 1.79 | 1.37–2.21 | – | 1.87 | 1.44–2.30 | – | 1.68 | 1.36–1.99 | – | |
| ADM | 2.07 | 1.65––2.49 | – | 1.87 | 1.33–2.40 | – | 1.88 | 1.20–2.56 | – | |
| Fixed values for r | ||||||||||
| r = 0.90 | CBT | 1.46 | 1.13–1.78 | −0.33 | 1.76 | 1.41–2.12 | −0.10 | 1.41 | 1.13–1.68 | −0.27 |
| ADM | 1.69 | 1.36–2.02 | −0.38 | 1.52 | 1.10–1.94 | −0.35 | 1.92 | 1.23–2.61 | 0.04 | |
| r = 0.75 | CBT | 1.69 | 1.31–2.07 | −0.10 | 1.91 | 1.51–2.30 | 0.04 | 1.59 | 1.32–1.86 | −0.09 |
| ADM | 1.94 | 1.57–2.31 | −0.13 | 1.75 | 1.29–2.20 | −0.12 | 1.93 | 1.23–2.62 | 0.05 | |
| r = 0.50 | CBT | 1.80 | 1.39–2.21 | 0.01 | 1.94 | 1.51–2.36 | 0.07 | 1.68 | 1.41–1.95 | 0.00 |
| ADM | 2.04 | 1.65–2.44 | 0.03 | 1.87 | 1.39–2.34 | 0.00 | 1.92 | 1.22–2.61 | 0.04 | |
| r = 0.25 | CBT | 1.84 | 1.41–2.26 | 0.05 | 1.93 | 1.49–2.37 | 0.06 | 1.72 | 1.44–2.00 | 0.04 |
| ADM | 2.07 | 1.66–2.47 | 0.00 | 1.91 | 1.43–2.39 | 0.04 | 1.91 | 1.21–2.61 | 0.03 | |
| r = 0.00 | CBT | 1.85 | 1.41–2.29 | 0.06 | 1.92 | 1.48–2.36 | 0.05 | 1.74 | 1.46–2.02 | 0.04 |
| ADM | 2.07 | 1.66–2.48 | 0.00 | 1.93 | 1.45–2.42 | 0.06 | 1.90 | 1.20–2.60 | 0.02 | |
SMD, standardised mean difference; CI, confidence interval; CBT, cognitive behavioural therapy; ADM, anti-depressive medication; BDI, Beck's depression inventory; BDI-II, BDI second edition.