2.3.1. Tension Tamer (TT) Intervention Group
TT is a patient-centered, iteratively designed breathing awareness meditation mobile application (app) compatible with Android or iOS platforms. The TT app’s content and implementation formats were guided by underlying tenants of self-determination and social cognitive theories [
22,
23]. Collectively, these theories maintain that one needs to develop self-efficacy, competence, and autonomous regulation (i.e., intrinsic motivation) for the desired behavior changes to initiate and sustain over time. The people, activity, context, and technology approach (PACT) model also guided TT app development and posits that users must feel at ease in using the technology and perceive its usefulness in helping them reach a desired goal [
24]. It is postulated that with positive feedback and social reinforcement (e.g., TT app’s immediate post-session heart rate feedback charts, tailored motivational and social reinforcement text messages based upon levels of adherence), self-efficacy and autonomous regulation will increase, contributing to consistent utilization and sustained engagement over time. An example message that a TT participant would receive might read:
“You completed two Tension Tamer sessions over the last 24 h! Remember, the more you practice, the more it becomes a part of your routine.”The TT app utilizes a smartphone’s camera lens to acquire continuous measures of heart rate via detection of fingertip pulsatile blood flow changes via proprietary reflective photoplethysmography software. The date and time stamp information of heart rate acquisition across the session is a proxy for adherence. The participant must keep the tip of their index finger on the camera lens during meditation sessions. Within 20–30 s, the app acquires a stable heart rate and continuously displays heart rate presented on a 4 beat rolling average. TT-app-derived heart rate has been validated against ECG at rest and during acute stress exposure (i.e., oral presentation, videogame challenge) [
19]. Additionally, there is a video clip guide, in which a moderator describes how to engage in BAM (diaphragmatic breathing, also known as belly breathing), while showing an individual engaging in BAM with attention to the expansion of the abdominal region when inhaling through the nose. There is also an audio guide, which automatically plays on the initial BAM session. A female with a British accent leads participants through the BAM session, including directions on finding a quiet, comfortable location to sit comfortably or lie down, activate the TT heart rate acquisition component, and engage in breathing in a slow, deep, relaxed manner, while attending to the sensations of one’s breathing. She also provides guidance on how to regain attention to one’s breathing when distractions occur (e.g., external noises, such as people talking, car horn blaring, intrusion of random thoughts, worries, etc.). After the initial session, users may elect to deactivate the audio guide on future sessions if desired.
A brief chime activates midway and at completion of the session. The TT app provides a timer on the screen, which displays the duration of each session. If there is 30 s of excessive movement of the phone preventing heart rate acquisition, the phone will vibrate and display a message on the app screen requesting less movement and to refocus upon engaging in the meditation session. If a participant has more than two disruptions during the session, the TT session halts and a message is presented requesting the participant to complete a session when they find a better time to engage in BAM. The TT app includes a technology assistance phone number button should users require any assistance in the future.
Immediately following completion of a TT session, users receive a feedback graph displaying average heart rate each minute and maximum decrease observed (see
Figure 2a). Users have the option to turn off (or reactivate) the audio BAM instructions, set middle or end of session alerts (chime, gong), and select different background themes of screenshots (e.g., nature, rock garden, beach scenes—see
Figure 2b). The TT app sends encrypted heart rate data to our institution’s HIPAA-compliant relational database management system via a securely authenticated Web API.
During the baseline visit following informed consent and randomization, a trained team member downloaded the TT app to the participant’s phone and instructed them in navigating each module (e.g., explained BAM, activating and deactivating the audio instruction guide, frequently asked questions, accessing feedback graphs, technology assistance phone line, etc.). Each participant was given additional guidance and feedback as needed, while practicing BAM and listening to the audio instructions to acquire their heart rate through using the app. When comfortable, they completed their first complete BAM session on their own using the audio instruction guide. After viewing the immediate post-session summary graph, participants had the opportunity to ask any questions they may have had.
Based upon results from our previous dose–response trial [
21], each TT participant was instructed to complete two 15-min daily sessions for the first month, decrease to two 10-min daily sessions for months 2 and 3, and then decrease to 5-min sessions for the remainder of the 12-month trial. If desired, one could engage in more than the 2 sessions/day dosage, however our analysis only included adherence to the prescribed dosage, which was determined to be most efficacious in a previous trial [
21]. For example, if a participant engaged in an extra session each day (i.e., 3 sessions instead of the prescribed 2), they received the same adherence score as a participant who completed the prescribed dosage, with each receiving a score of 1.0.
2.3.2. Lifestyle Education Program Delivered via Smartphone (SPCTL)
The SPCTL attention control group received the same twice-daily dosage schedule for engagement in a walking or running program using the RunkeeperTM app (month 1: 15 min sessions; months 2 and 3: 10 min sessions; months 4–12: 5 min sessions). As with the TT group, if they wished to engage in longer or more frequent daily sessions, this was permitted. A research assistant downloaded the RunkeeperTM app to each SPCTL participant’s phone, demonstrated all features of the app, and ensured the participants’ understanding of the app. The app was used to enable tracking and provide feedback of the duration of daily planned physical activities (e.g., outdoor walk or run, treadmill, strength exercises, etc.) participants performed the amount of total daily activity using the phone’s built in accelerometer (steps/day) and GPS software for distance tracking.
The SPCTL group also received the same frequency of SMS messages as the TT group, however content did not pertain to their level of regimen adherence. They received healthy lifestyle-behavior-related educational messages associated with their heart-healthy diet, low sodium intake, non-smoking, physical activity, sun exposure, and other factors. An example message that a SPCTL participant would receive might read: “Positive mental health allows people to reach their full potential, cope better with stress, and make meaningful contributions to their communities.” As they progressed in the trial, similar to the TT group, participants could immediately access cumulative charts showing their amount of steps/day and duration of exercise episodes per week and month, as well as their adherence levels to their dosage schedules across the 12 months.