Evaluating reliable and clinically significant changes in health outcomes of a mindfulness-based cognitive defusion training program among older adults with mild cognitive impairment: a randomized controlled trial

Background: Recognizing perceived stress as a modifiable risk factor, mindfulness-based programs show promise for stress mitigation in older adults with mild cognitive impairment (MCI). Objective: To assess the efficacy of a mindfulness-based contextual cognitive defusion training (M-bCCDT) program on perceived stress and other health outcomes, and to examine the reliable and clinically significance of these improvements at individual-level among older adults with MCI. Design: A two-arm, assessor-blinded randomized controlled trial. Settings and participants: 102 community-dwelling older adults with MCI. Methods: Participants were randomly allocated to either a M-bCCDT program (weekly 60-minute sessions for 8 weeks, followed by 12 weeks of unsupervised practice) or health promotion classes. Measures of perceived stress, memory function, global cognitive function, psychomotor speed and mindfulness awareness were collected at baseline (T0), 8-week (T1) and 20-week (T2). Intervention effects were assessed at a group level (Generalized Estimating Equation, GEE) and individual level (Reliable and Clinically Significant Changes, RCSC). Results: The M-bCCDT program demonstrated significant interaction effects in perceived stress compared to the wait-list control group by GEE analysis (β_T1 = -3.686, 95% CI [-5.397, -1.976]; β_T2 = -7.608, 95% CI [-9.387, -5.829]). Furthermore, this program also showed significant efficacy in memory function, psychomotor speed and mindfulness awareness. RCSC indicated that 30 participants (59%) in the intervention group showed statistically significant improvement in perceived stress at 8-week, with 7 (14%) clinically significant. This increased to 38 (75%) with 20 (39%) clinically significant at 20-week. Secondary outcomes also showed statistically and clinically significant improvements over time, but no improvement in global cognitive function at the individual level. Conclusions: The M-bCCDT program positively impacted perceived stress and mindfulness awareness in older adults with MCI, facilitating the improvements in memory and psychomotor speed, with these benefits sustained for 20 weeks. It offers a systematic approach for community healthcare providers in MCI stress management.