Effects of school-based mindfulness intervention on health-related quality of life: moderating effect of gender, grade, and independent practice in cluster randomized controlled trial

Abstract

<p><strong>Object</strong> <br></p><p>We investigated the impact of a school-based 9-week mindfulness program vs. active control program (relaxation) and inactive control group on children's self-reported Health-Related Quality of Life (HRQoL) moderated by gender, grade, and independent practice. <br></p><p><strong>Method</strong> <br></p><p>In total 3519 (50/50% boys/girls) Finnish students aged 12-15 years from 56 schools were randomized into mindfulness intervention, active, and inactive control groups. HRQoL was measured at baseline, at 9 weeks, and at 26 weeks and analyzed with multilevel linear modeling. <br></p><p><strong>Results</strong> <br></p><p>Significant improvement on HRQoL was found (β = mean difference) (β = 1.587, 95% CI 0.672-2.502, <em>p</em> < 0.001) after 9 weeks and at 26 weeks of follow-up among students in the mindfulness group as compared to the active control group. Moderating effects on HRQoL were found for gender, grade, and independent practice: girls, 7th and 8th grade students, and students with regular independent mindfulness practice benefited most. <br></p><p><strong>Conclusions</strong> <br></p><p>Gender and developmental stage may moderate the effects of mindfulness interventions on HRQoL and offer guidance in designing effective promotive interventions for children and adolescents.</p>