Table 5.
Risk ratio of the experimental and control groups at the follow-up stage.
| Study | Follow-up duration | Experimental group | Comparison group | RR | 95% CI | Major findings | ||
|---|---|---|---|---|---|---|---|---|
| Events.M | Total | Events.M | Total | |||||
| [45] | 12 month | 19 | 68 | 11 | 42 | 1.07 | 0.57–2.01 | No evidence was found that the coping with depression course prevented depressive episodes |
| [47] | 12 month | 37 | 354 | 62 | 354 | 0.60 | 0.41–0.87 | This result indicates that the risk of developing major depression disorder was significantly lower in the i-CBT group when compared to the control group |
| [48] | 24 month | 8 | 40 | 16 | 47 | 0.59 | 0.28–1.23 | This significant preventive effect persisted, but at a diminished level at the 18- and 24-month follow-ups |
| [13] | 12 month | 10 | 93 | 20 | 88 | 0.47 | 0.23–0.95 | This result indicates that effective treatment of subclinical depression may yield a preventive effect for the exacerbation of depressive symptoms |
| [54] | 6 month | 0 | 20 | 2 | 23 | 0.23 | 0.01–4.50 | The results of this study suggest that CBT is beneficial for residents with subclinical depression |
| [56] | 12 month | 0 | 21 | 2 | 20 | 0.19 | 0.01–3.75 | This study found that the intervention group had a lower MDE incidence than the comparison group, although this difference did not attain statistical significance |
| [15] | 12 month | 21 | 149 | 41 | 146 | 0.50 | 0.31–0.81 | This result demonstrated that, for patients with subclinical depressive symptoms and persistent back pain, intervention significantly reduced the incidence of MDE over a 12-month follow-up period |
| [42] | 12 month | 2 | 36 | 1 | 32 | 1.78 | 0.17–18.69 | The groups did not differ in the proportion of patients that developed clinical anxiety and/or depression |
| [59] | 6 month | 6 | 65 | 5 | 59 | 1.09 | 0.35–3.38 | In fact, except for a very small number of indicated prevention studies in which a decrease in the incidence of depression was found, most studies have only been able to detect reductions in depression symptoms |
| [60] | 12 month | 13 | 107 | 20 | 109 | 0.66 | 0.35–1.26 | The incidence of major depression among participants in the experimental condition was reduced by a third compared with the control condition |
| Overall: I2 = 0%, RR = 0.62, Sig (p=0.64) Total RR = 0.62; 95% CI (0.50–0.77) |
NNT = 8.79; 95% CI: 6.67–14.55 | |||||||
Abbreviations: CBT, cognitive behavioral therapy; CI, confidence interval; MDE, major depressive episode; NNT, number needed to treat; RR, risk ratio.