Using linear mixed-effects models, in intent-to-treat analyses, cortisol slopes were maintained over time in both SET (P = .002) and MBCR (P = .011) groups, relative to the control group, whose cortisol slopes became flatter.
Women in MBCR improved more over time on stress symptoms, as compared with women in both the SET (P = .009) and control (P = .024) groups.
Per-protocol analyses showed greater improvements in the MBCR group in quality of life compared with the control group (P = .005) and in social support compared with the SET group (P = .012).
In this largest trial to date, MBCR was superior for improving a range of psychological outcomes for distressed survivors of breast cancer. Both SET and MBCR also resulted in more normative diurnal cortisol profiles than the control condition.