Moderators of Intervention Efficacy in the Pathways to Wellness Trial of Survivorship Education and Mindfulness Meditation for Younger Breast Cancer Survivors

Abstract

PURPOSE Depression is associated with poor outcomes in breast cancer survivors (BCSs), with higher prevalence among younger women. The Pathways to Wellness (PTW; ClinicalTrials.gov identifier: NCT03025139 ) randomized controlled trial (RCT) demonstrated beneficial effects of two behavioral interventions (survivorship education [SE] and mindful awareness practices [MAPs]) on depressive symptoms in younger BCS. We conducted an exploratory secondary analysis to identify moderators of intervention effects. METHODS Women diagnosed with stage 0 to III breast cancer at or before age 50 years who completed cancer treatment were randomly assigned to 6 weeks of SE (n = 81), MAPs (n = 85), or waitlist control (WLC; n = 81). Moderators assessed at baseline included psychological distress (depression and anxiety), intervention preference, preparedness for survivorship, and time since initial diagnosis. Linear regression models tested the modifying effects of each variable on postintervention depression in SE versus WLC and MAPs versus WLC. RESULTS Baseline levels of depression (β = –.03, P < .01) and anxiety (β = –.64, P = .02) moderated effects of SE on depressive symptoms, as did preparedness for survivorship (β = 3.17, P = .02). Participants randomly assigned to SE who had the highest levels of depression or anxiety and who felt least prepared for survivorship showed the largest reductions in depressive symptoms from preintervention to postintervention. Similar effects were not observed for MAPs. Intervention preference and time since diagnosis did not moderate intervention effects for either SE or MAPs. CONCLUSION Our 6-week, group-based SE program may be most beneficial for women with higher levels of psychological distress and those who feel least prepared for cancer survivorship. By contrast, a 6-week mindfulness awareness practice intervention appears to benefit younger BCS regardless of pretreatment characteristics.