4. Discussion
anxiety, mood disturbance, breathing-related, insomnia, depression
SECONDARY, HYPERTENSION
This study successfully demonstrated the feasibility of a three-arm intervention trial, involving a 20-min daily practice for 8 weeks, conducted fully remotely with wearable devices and a virtual laboratory visit with a stress induction task. Our research team screened 91 individuals who showed an interest in participating, and then successfully enrolled and randomized 18 healthy young adults (5 in the SPB group, 6 in the M group, and 7 in the SPB + M group) from multiple states in the U.S. over a 5-month period, at a rate of about one participant per week. With a 20% recruitment-to-randomization rate, we then achieved our target rates of overall study completion (100%), daily practice adherence (73%), daily sleep log completion (98%), and rate of analyzable heart rate data from virtual lab visits (92%), indicating that a larger follow-on study with these procedures is feasible. Furthermore, while this feasibility study was not sufficiently powered for statistical analysis, we observed intervention-specific patterns of breathing and mindfulness consistent with a “dismantling” framework, whereby only the SPB and SPB + M participants demonstrated spectral HRV patterns reflecting the 6-bpm guidance, and only M and SPB + M yielded group-wise increases in the mindfulness ratings from pre to post intervention. In addition to the measures reported here, we collected other questionnaires for the exploratory aims, including scales for self-esteem, satisfaction with life, social connectedness, emotion regulation, desirability of control, psychological flexibility, and circadian patterns, as well as performance metrics from the Stroop test. The data collection rates for these secondary measures were similarly high.The primary aim of the study was to test the feasibility of dismantling the component-specific effects of yogic breathing (mindfulness, breathing, and their combination) via a fully remote three-arm RCT. Therefore, we limited our focus to the feasibility-related data rather than the “outcomes” and we reported the results with descriptive statistics and data visuals but not the inferential statistics, per the recommended guidelines [Recognizing that many mindfulness and yoga interventions are much longer in duration, such as Mindfulness-Based Stress Reduction (MBSR) that entails 2.5-h weekly group sessions for 8 weeks plus a full-day retreat and 45-min daily formal practice [In this feasibility study, we focused on a healthy young adult population, and used technology-based approaches to improve accessibility and decrease the participants’ burden. Compared to the M and SPB + M groups, the SPB group had higher MASQ scores for in three of the scales: distress, anxious arousal, and total mood disturbance. However, no differences were observed for the feasibility outcomes, suggesting that the study is potentially feasible for people with higher levels of stress, depression, and/or anxiety. Correspondingly, this type of study design may have a promising application for hypertension, insomnia, and other clinical groups. Studies with remotely delivered mindfulness-based interventions have been increasing [As highlighted above, the three groups were qualitatively distinguishable in terms of the HRV spectra during practice (In this fully remote trial, we encountered a few sporadic technical issues. Because we used a freely available, web browser-based version of the Stroop test, there were two occasions pre intervention and two occasions post intervention (11%) when the server was unavailable to successfully complete the task. In all cases, we used a backup version of the test to approximate the stress induction aspect, although we were not able to obtain comparable performance statistics. Consistent with a common drawback of telehealth, there were also periodic connectivity issues with the video platform, in which case we used telephone calls to maintain contact with the participants to complete as much of the virtual lab visit and wearable data collection as possible. As described above, there were three occasions when we were not able to collect the analyzable heart rate data; in one case, there were connectivity issues for the participant, and in the other two cases, there was a misunderstanding of the recording procedure during the intervention practice recording, which was able to be immediately remedied for all subsequent recordings. Overall, we were encouraged by the relatively few issues that arose and the success of troubleshooting efforts.A few additional limitations are important to note. Due to local IRB regulations, we were unable to advertise on social media or through university posting boards, and instead, we used ResearchMatch.org as the sole advertising modality. While we garnered substantial participant interest through this resource, our screening-to-randomization ratio was low (20%) and may have been improved had we been able to use more targeted, local advertisement methods. Second, the relatively younger healthy adult population in this study showed a high adherence and reported a low level of difficulty in following the technology-based tests and measures, which may overestimate the anticipated feasibility for older adults or other populations when considering the ease-of-access related to videoconferencing and wearable technology. Future studies are encouraged to test the feasibility of such a design in other populations, especially using a qualitative or mixed methods analysis. It is also notable that two of the M participants breathed at rates near 6 bpm (0.1 Hz), presumably corresponding to an effortful slowing of the breathing, despite no specific instruction to breathe at that rate. The variations in breathing rates across these interventions create a challenge for conducting an HRV-based analysis of the vagal tone or parasympathetic activation per conventional approaches using a cutoff of 0.12–0.15 Hz. However, one possible solution that future studies could implement is a recording block of paced breathing, for example at 15 bpm (0.25 Hz), for all participants at the end of the final laboratory visit, in order to obtain the equivalent breathing conditions while not inadvertently influencing the breathing-related instructions for each intervention arm.