Table 2.
Risk of bias ratings of the trials included in the systematic review
| Trials | Sequence of generation | Baseline comparability | Allocation concealment | Blinding of outcome assessors | Comparability of completers and drop-outs | Use of intention-to-treat |
|---|---|---|---|---|---|---|
| Brown et al, 201627 | ? | +a | ? | + | ? | − |
| Hou et al, 201433 | − | − | − | + | +b | − |
| Lavretsky et al, 201328 | − | − | ? | + | ? | + |
| Losada et al, 201532 | − | +c | ? | + | +d | + |
| Oken et al, 201029 | − | − | − | + | ? | + |
| Waelde et al, 201730 | ? | +e | ? | + | − | − |
| Whitebird et al, 201331 | − | +f | ? | + | − | − |
Notes: +: High risk of bias; −: low risk of bias; ?: unclear risk of bias.
The percentage of primary caregivers in the intervention group was significantly higher than that in the control group (p<0.05).
The drop-outs (n=27) were significantly younger (p<0.05) and had lower levels of physical activity than the participants (n=114).
The mean time of caring (years) was longer in the control group than in the intervention group (p<0.05).
Completers spent fewer hours caring and had lower levels of depression at baseline than the drop-outs (p<0.05).
The baseline log cortisol slope was flatter in the intervention group than the control group, indicating a higher stress level of participants in the intervention group.
The baseline level of anxiety was significantly lower in the intervention group than in the control group.