Randomized Controlled Trial of Group‐Blended and Individual‐Unguided Online Mindfulness‐Based Cognitive Therapy to Reduce Psychological Distress in People With Cancer

Objective Online mindfulness‐based cognitive therapy (eMBCT) can reduce psychological distress in people with cancer, but adherence and scalability could be improved. Through co‐creation, we developed two eMBCT formats: group‐blended and individual‐unguided. This trial compared the effects of the two eMBCT to care as usual (CAU) on psychological distress and other mental health outcomes in people with cancer. Methods In this parallel, three‐armed randomized controlled trial, people with cancer were randomly allocated to group‐blended eMBCT, individual‐unguided eMBCT, or CAU. Participants completed baseline, mid‐treatment, post‐treatment, and 3 months follow‐up assessments. The primary outcome analyzed in the intention‐to‐treat (ITT) population was psychological distress (Hospital Anxiety and Depression Scale) at post‐treatment. Results In total, 186 participants were randomized to group‐blended eMBCT ( N = 57), individual‐unguided eMBCT ( N = 75), or CAU ( N = 54). Most participants were female (81%) with breast cancer (49%), and treated with curative intent (76%). In ITT analyses, group‐blended eMBCT participants reported significantly lower levels of psychological distress at post‐treatment (Cohen's d = 0.38) and follow‐up (Cohen's d = 0.64) than those receiving CAU, while individual‐unguided eMBCT participants only had significantly less psychological distress at follow‐up (Cohen's d = 0.48). Additionally, participants in group‐blended eMBCT had less rumination and greater mindfulness, decentering, and self‐compassion than those in CAU at follow‐up. Participants in individual‐unguided eMBCT had greater decentering than those in CAU at post‐treatment and follow‐up, and less rumination and greater mindfulness skills than CAU at follow‐up. Conclusions Compared to CAU, both eMBCT conditions were effective in reducing psychological distress and could be an accessible, and potentially low‐cost intervention to reduce distress in people with cancer. Trial registration Dutch Registry CCMO, NL73117.091.20; clinicaltrials.gov , NCT05336916