Maeno Takashi

Abstract Objectives This study aimed to evaluate the effectiveness of the Intervention program of Mindfulness and Compassion against COVID-19 (IMACOCO), an online mindfulness-based intervention (MBI), in enhancing mindfulness, mental health, well-being, and productivity among working individuals during the COVID-19 pandemic. Additionally, the study examined the program’s efficacy in individuals directly impacted by the pandemic through a randomized controlled trial and pre-post program comparisons. Method Three hundred working adults, including office workers, educators, and medical welfare workers, were randomly allocated to the intervention or waiting control group. An 8-week online MBI program, with pre-, interim (4 weeks), and post-program (8 weeks) evaluations, was conducted via the Internet; standardized questionnaires were used to assess mindfulness, psychological distress, life satisfaction, and productivity. After the initial 8-week program, the waiting control group participated in the same program and evaluation surveys for pre-post comparisons. Results There were 99 participants in the intervention group and 111 in the control group. Significant increases in mindfulness (FFMQ) and life satisfaction (SWLS) as well as decrease in psychological distress (GHQ-12) were observed primarily in the intervention group (Cohen’s d = 0.18–0.52). Furthermore, the pre-post comparisons with 168 participants demonstrated significant improvements in productivity (Cohen’s d = 0.26), and stratified analysis revealed that participants affected by COVID-19 showed more pronounced benefits in mindfulness and life satisfaction than those who were unaffected. Conclusions Implementing an online MBI program (IMACOCO) can be a potent strategy to reduce mental stress and enhance overall well-being and resilience, in a disaster-prone world. Preregistration This study is not preregistered.