Conclusions
This study integrated a mindfulness intervention into conventional diabetes care and education to target DD in veterans. Statistically significant improvements in most outcomes were observed in both the intervention and control arms over 24 weeks. Since DSMES is a critical component of diabetes care,7 it likely accounts for improved outcomes in the control arm. However, research has shown that the durability of DSMES effects is variable,36–39 and the value of multifaceted programs that integrate psychobehavioral interventions into DSMES is increasingly being recognized.14 40 41 This study showed a statistically and clinically significant reduction in DD after 12 weeks compared with DSMES control. In addition, a significant group by time intervention effect was observed for general dietary behaviors, and there were non-significant distal trends toward improvement in other secondary outcomes that may suggest longer-lasting effects with the intervention.
Our findings reiterate those from a systematic review and meta-analysis of eight RCTs involving 841 participants with diabetes that showed increased longer-term efficacy of MBI in mitigating DD compared with shorter term.42 The meta-analysis also identified five factors that influence the effect size (Cohen’s d) of MBI on DD: higher baseline DD (d=0.48), MBSR-based design (d=0.58), group format (d=0.36), home practice assignments (d=0.42), and assessment of longer-term effects (d=0.56). Mind-STRIDE incorporates each of these five factors, which may account for its efficacy in reducing DD between weeks 12 and 24 compared with control.
Although studies have identified DD as a positive predictor of HbA1C in persons with diabetes,10 PAID scores did not correlate with HbA1C in this sample of veterans. A table of baseline associations with DD is shown in the online supplemental materials. Although the burden of diabetes self-management, directly associated with DD, is likely to increase with the addition of new therapies and care tasks as metabolic outcomes worsen, some persons may not internalize feelings of distress in response to this burden. Further, participants with higher HbA1C may have a variety of challenges that influence their response to these types of interventions, such as conflicting priorities, low literacy, or social determinants of health that were not assessed. The aforementioned meta-analysis42 provides context for MBI effects on DD and HbA1C, reporting greater reductions in DD when baseline HbA1C was <8% and the duration of follow-up was >6 months. This aligns with the results of our stratified analyses that found stronger intervention effects on DD after 12 weeks and when baseline HbA1C was <8.5%. Accordingly, baseline HbA1C and its correlation to DD may be relevant considerations for future mindfulness studies with veterans and other persons with diabetes.
The effects on other secondary outcomes are also noteworthy. Nutrient-specific and special diet domains of the SDSCA improved significantly in both arms without a significant intervention effect, possibly due to new knowledge gained from dietary counseling provided by the DSMES dietitian. In contrast, general diet improved in both groups, with a significant intervention effect that may reflect behavioral changes related to increased mindful attention to healthy eating. Interestingly, previous research43 found a 12 min mindful attention exercise mitigated the relationship between hunger and calorie-dense junk food consumption, resulting in healthier food choices. According to those researchers, mindful attention may be a metacognitive component of mindfulness that can modulate motivational states and play a central role in eating behaviors. Weight loss was not observed in either group despite reported improvements in dietary behaviors. This could be because modest dietary improvements may not translate to sufficient caloric reductions for weight loss, particularly in individuals with metabolic dysregulation.
The secondary outcomes diabetes self-efficacy, PTSD, and depressive symptoms improved in both arms without significant intervention effects. This is not surprising since prior DSMES and MBI research has shown positive outcomes in these areas, attributed to stress reduction, social support, and increased feelings of well-being.7 12 44 It is striking, however, that these improvements continued to trend after 12 weeks in the Mind-STRIDE intervention arm compared with DSMES control, suggesting longer-lasting effects when an MBI is integrated with DSMES.
It is difficult to theorize about mechanisms, however, since measurement of mindfulness is challenging.45 46 For example, a systematic review of 85 studies showed that brief mindfulness interventions positively impacted health-related outcomes, but it is unclear if these effects were mediated by changes in mindfulness.47 Accordingly, previously reported baseline analyses from the current study showed a significant inverse association between mindfulness (MAAS) and DD, whereby greater mindfulness predicted lower DD.48 However, our longitudinal analyses showed that MAAS scores did not increase alongside reductions in DD as would have been expected. It is possible that MAAS and other such instruments may not be sensitive to changing states of mindfulness.
Nonetheless, Mind-STRIDE is timely and responsive to veterans’ interest in mindfulness. In a survey of 185 veterans, 58% were interested in learning about mindfulness and 30% had practiced mindfulness during the past year.49 Over 75% of those who practiced reported perceived benefit. However, Martinez et al50 identified numerous barriers to veteran participation in traditional 8-week MBSR programs, including misinformation from healthcare practitioners (eg, MBSR may diverge with religious beliefs), scheduling conflicts, limited access, aversion to group activities, inability to commit to home practice, and difficulty understanding its concepts. Mind-STRIDE addresses several of these barriers by tailoring an MBSR-inspired intervention with home practice support that can be integrated into current diabetes care processes.
Strengths and limitations
This RCT addressed existing gaps in knowledge regarding the efficacy of mindfulness interventions in veterans with DD, the effects of mindfulness as an adjunct to diabetes care and education, and the use of a mobile app to support and track engagement. Unlike similar studies that primarily relied on self-report, this study also used objective measures, increasing the validity of our findings. Mind-STRIDE and DSMES were delivered by consistent teams of interventionists and educators, which decreased potential instructor bias. The interventionists had basic experience with MBSR, but extensive experience or certification was not required. Thus, trained members of diabetes care teams like psychologists, social workers, nurses, dietitians, or health coaches can readily facilitate this type of intervention in conjunction with conventional diabetes care and education. Satisfaction was high and over two-thirds of the participants remained engaged over 6 months.
We note several limitations. Although a retention rate of 86% is acceptable, 31% of Mind-STRIDE participants either dropped out or did not engage in mindfulness practice. Perhaps more frequent telephonic support or additional booster(s) would have conferred greater benefits beyond the DSMES control. The study was also conducted in person at one VA site, thus limiting accessibility and generalizability. Despite specific recruitment efforts, there were few female participants. Finally, the duration of the study did not allow for examination of distal effects beyond 24 weeks.
In summary, a technology-supported, MBSR-inspired mindfulness intervention integrated with DSMES significantly reduced DD after 12 weeks compared with DSMES control. Effects were greater when baseline HbA1C was moderately elevated (<8.5%). Examination of long-term outcomes, underlying mechanisms, and feasibility of virtual delivery is warranted.