Effect of blended and unguided online delivery of mindfulness-based cognitive therapy versus care as usual on distress among cancer patients and survivors: protocol for the three-arm parallel randomized controlled buddy trial

Background: One third of cancer patients and survivors experience psychological distress. Previous studies have shown that online mindfulness-based cognitive therapy (eMBCT) supports cancer patients and survivors in managing distress. Lack of peer support and asynchronicity during online interventions have been reported as barriers for treatment adherence and can result in higher drop-out rates. Considering this, two new formats of eMBCT were created. The primary objective of the Buddy trial is to evaluate the (cost) effectiveness of blended and unguided eMBCT versus care as usual (CAU) on psychological distress among cancer patients and survivors. Secondary objectives include evaluating effects on other psychological outcomes and investigating working mechanisms and treatment effect moderators. Methods: The Buddy trial is a parallel three-armed randomized controlled trial. Participants will be randomly assigned to blended therapist-assisted eMBCT, unguided individual eMBCT or CAU. Eligible participants will be Dutch-speaking adult cancer patients or survivors with access to internet. The primary outcome will be psychological distress scores as assessed by the Hospital Anxiety and Depression scale immediately post-treatment. Secondary outcome measures include fear of cancer recurrence (FCRI), fatigue (CIS-F), rumination (RRQ), mindfulness skills (FFMQ), decentering (EQ), self-compassion (SCS-SF), positive mental health (MHCSF), health related quality of life (EQ-5D), and costs associated with psychiatric illness (TiC-P). Outcome measures will be evaluated at baseline, mid-treatment, immediately post-treatment, and three-, six-, and nine-months follow-up. Possible mediators, such as engagement with interventions (TWEETS), and moderators will be also analyzed. Discussion: There is room to improve eMBCT for cancer patients prior to implementation to ensure adherence and scalability. Blended and unguided eMBCT may reduce psychological distress and improve quality of life and be easily accessible to cancer patients and survivors. Trial registration clinicaltrials.gov, NCT05336916, registered on April 20th, 2022. https://clinicaltrials.gov/ct2/show/NCT05336916.