Feasibility and Impact of Yoga, Self-hypnosis and Cognitive-behavioral Group Interventions in Improving Well-being of Breast Cancer Patients

This study had two objectives. The fist one was to determine the interest of breast cancer patients in participating in one of three group interventions (cognitive-behavioral therapy, yoga or self-hypnosis) by assessing the participation rate, the reasons for choosing a particular group or decline the offer. The second objective was to evaluate and compare the benefits of these three interventions on emotional distress, QoL, sleep quality and mental adjustment to cancer.

Eligible breast cancer patients were identified through an institutional database or by referring physicians and were approached by phone to inform them of the intervention. They were given a choice between the three group interventions: CBT, yoga and self-hypnosis. Patients who agreed not to participate in any of the interventions were included in the control group. After giving written informed consent, patients completed a baseline assessment including self-reported measures. Follow-up assessment was conducted one week after the group intervention, and at a 3-month and 9-month follow-up. Interventions were proposed according to previous results showing the patient's interest in CBT, yoga and self-hypnosis, and the expertise of the team. Each intervention included 6 sessions of 1.5 hours.

The primary outcome measure was the interest in the three interventions (participation rate in each group). Since the study was first designed to determine interest, no sample size calculation was performed. Secondary outcomes were responses concerning emotional distress, QoL, sleep quality and mental adjustment to cancer assessed with self-reported questionnaires before and after the group interventions.

Descriptive statistics (percentages, means and standard deviation (SD)) were used to describe the proportions of patients who were interested in the group interventions and to examine their demographic, medical and psychological data. Baseline time 0 demographic, medical and psychological data were compared between groups to test for initial group equivalency using inferential statistics: analysis of variance (ANOVA) and Chi-square test, as appropriate. To be considered for the data analysis, patients had to attend at least three sessions. Multivariate analyses were calculated regarding group interventions and time of medical treatments (during or after chemo/radiation therapy). The pre- and post-assessment comparison of each measure within each group was made using the Wilcoxon test for matched pairs. All statistical tests were two-tailed, and a P-value <0.05 was considered statistically significant. Investigators also calculated Cohen's d effect size for each group. The analyses were performed with SPSS Version 21.0 (IBM Corp., Armonk, N.Y).