These positive effect sizes indicate that the average patient receiving the intervention is better off than between 57% and 65% of those not receiving the intervention.
In summary, it appears that when psychosocial interventions are offered to patients who are found to be experiencing distress (e.g., anxiety, depression), the efficacy of the intervention is very strong. Thus, the overall positive benefit for psychosocial interventions seems to be greater with those who seem to need it most.[35,36]
Randomized trials of group interventions for breast cancer
The four studies described below are representative of randomized clinical trials testing the efficacy of small-group psychosocial interventions for U.S. women with early-stage breast cancer. Note that the studies vary in total treatment time, from 8 hours [Level of evidence: I] to 20 hours [38,41][Level of evidence: II] to 27 hours,[Level of evidence: I] and have a variety of intervention components.
Investigators tested the efficacy of a 10-week, 2-hours-per-week group cognitive-behavioral stress management intervention. One hundred newly treated women with breast cancer were randomly assigned to either the intervention or to a control condition. The psychosocial intervention consisted of ten 2-hour group sessions during which didactic material was presented, intermixed with a variety of experiential exercises and homework assignments. The overall intervention focused on learning to cope better with daily cancer-related stressors. Topics included the following:
- Progressive muscle relaxation with imagery.
- Cognitive restructuring.
- Interpersonal conflict resolution.
- Assertion training.
- Enhanced social support.
The control condition consisted of a day-long seminar in which participants received a condensed version of the intervention with significantly less time to interact within the group. Among intervention participants, results showed the following:
- A decrease in depression.
- No change in other measures of emotional distress.
- An increase in "benefit finding" (i.e., reporting that having breast cancer had made positive contributions to their lives) and optimism.
In a larger (N = 199) randomized study conducted by the same research group  on women with stage 0 to stage III nonmetastatic breast cancer, an intervention similar to that in the first study produced somewhat greater sustained decreases in cancer-related intrusive thoughts and sustained improvements in anxiety.
Another study examined an 18-week, 1.5-hours-per-week group intervention consisting of psychological strategies designed to reduce stress, enhance mood, alter health behaviors (diet, exercise, smoking), and enhance adherence to cancer treatments. Outcome measures included emotional distress, health behaviors, and immune responses. Two hundred twenty-seven women, all of whom had received surgery for regional breast cancer, were randomly assigned to either the intervention group or an assessment-only control condition. Compared with the control group, the intervention group showed the following:
- Significantly less anxiety.
- Improved social support.
- Better dietary behaviors.
- Reduced smoking.
- Increase in symptom reduction and functional status.