Use of Mobile Technology Paired with Heart Rate Monitor to Remotely Quantify Behavioral Health Markers among Military Reservists and First Responders.

INTRODUCTION: Heart rate variability (HRV) is a biological marker that reflects an individual's autonomic nervous system regulation. Psychological resilience is an individual's ability to recover from an adverse event and return to physiological homeostasis and mental well-being, indicated by higher resting HRV. The Biofeedback Assisted Resilience Training (BART) study evaluates a resilience-building intervention, with or without HRV biofeedback. This article evaluates the feasibility of remote psychophysiological research by validating the HRV data collected. MATERIALS AND METHODS: The BART platform consists of a mobile health application (BART app) paired to a wearable heart rate monitor. The BART app is installed on the participant's personal phone/tablet to track and collect self-report psychological and physiological data. The platform collects raw heart rate data and processes HRV to server as online biofeedback. The raw data is processed offline to derive HRV for statistical analysis. The following HRV parameters are validated: inter-beat interval, respiratory sinus arrhythmia, low-frequency HRV, biofeedback HRV, and heart period. Bland-Altman and scatter plots are used to compare and contrast online and offline HRV measures. Repeated-measures ANOVA are used to compared means across tasks during the stress (rest, stress, and recovery) and training (rest and paced breathing) sessions in order to validate autonomic nervous system changes to physiological challenges. RESULTS: The analyses included 245 participants. Bland-Altman plots showed excellent agreement and minimal bias between online and offline unedited inter-beat interval data during the stress session. RMANOVA during the training session indicated a significant strong effect on biofeedback HRV, F(11,390) = 967.96, P < .01. During the stress session, RMANOVA showed significant strong effect on respiratory sinus arrhythmia and low-frequency HRV, and a significant but weak effect on heart period. CONCLUSIONS: The BART digital health platform supports remote behavioral and physiological data collection, intervention delivery, and online HRV biofeedback.

Mental health, stress, and resilience correlates of heart rate variability among military reservists, guardsmen, and first responders.

The use of heart rate variability (HRV) for monitoring stress has been growing in the behavioral health literature, especially in the areas of posttraumatic stress disorder, stress reactivity, and resilience. Few studies, however, have included general populations under workplace conditions. This study evaluates whether military and other first responders show lower HRV during stress than at baseline and greater post stress rebound, controlling for a myriad of potential confounders. A convenience sample of Reserves, National Guard, veteran, fire, and police personnel provided HRV and self-reported questionnaire responses before, during, and after a cognitive-stressor task with a smart phone application. Timing of HRV application; mental and physical health scores; coping and posttraumatic growth indicators, including being open to new possibilities; and emotional support were predictors of trajectories of the HRV response to stress. Findings from this exploratory study emphasize the strong link between stress and relaxation breathing in both respiratory sinus arrhythmia and low frequency heart rate variability and the need for controlling potential covariates for understanding the relationship between HRV and the stress response and providing a basis for hypothesis driven research.