Discussion
multiple behavior, fatigue, HL
BLOOD, HEART, LUNG, DISEASES
We evaluated 3 smartphone app notification intervention strategies sent to eFHS participants in a randomized trial aimed at improving the use of a smartwatch and a digital BP cuff for the remote monitoring of HR and BP. We observed evidence that personalized motivational notifications increased adherence over 3 months for BP data transmission and over 6 months for BP and HR transmission. Personalization included the participant’s name, and the message content was contextualized to the individual’s device use for each week of the trial. The use of the smartwatch and the BP cuff decreased over time, but the proportions of participants transmitting BP and HR data were about 10% higher in the personalized versus standard notification groups. There was little or no evidence that morning versus evening notifications or weekend versus weekday notifications were associated with adherence. In an exploratory aim, we did not observe a difference in smartphone app survey completion between intervention groups, but the analysis may have been underpowered. This trial provides evidence that short personalized motivational messaging offers an easy, scalable strategy to increase adherence with device use that potentially can be used in other large digital intervention studies.The investigation of a diverse set of digital health studies, including a range of diseases in more than 100,000 participants, revealed early user disengagement with a median study retention across all studies of fewer than 6 days [We observed that compared to younger participants, older participants were more likely to transmit BP and HR data. This finding appears to be consistent with another study that reported older age was associated with retention time [Our trial used weekly notifications to enhance the use of digital devices over 6 months to monitor BP and HR. We chose a weekly delivery to limit participant burden and associated notification fatigue observed in other trials. However, future investigations are needed to examine the intensity of notification delivery to determine whether more frequent notifications would result in higher observed device use.Our trial did not find any clear evidence for an effect of the day of the week or time of day on device use. In contrast, a trial of the effect of notification messaging on engagement with a wellness app showed that the effect was greatest when delivered on the weekend at midday [Notification content that includes multiple behavior change strategies [We embedded this trial in the eFHS, which provides several strengths. FHS participants have been enrolled in the parent study for over a decade (first examination from 2002-2005), demonstrate loyalty to the parent study; the participants have developed trust in parent study investigators and staff that may have facilitated higher levels of retention and engagement than seen in other e-cohorts [Our study also has some limitations that merit comment. We did not adjust for multiplicity related to coprimary BP and HR outcomes. We could have considered a multiplicity testing procedure, such the Holm procedure, to preserve the family-wise error rate and calculated the required sample size for the simple disjunctive power [Brief nonobtrusive personalized motivational smartphone app notifications delivered once per week significantly increased the use of a smartwatch and wireless BP device in middle-aged to older adults for monitoring cardiovascular measures (HR and BP) over 6 months. These simple prompts can be easily incorporated and scaled by other digital health studies to promote long-term engagement. Larger studies of more diverse participants are needed, as well as further study of the impact of notification strategies for digital and mobile health monitoring on health outcomes.This study was presented as an abstract at the American Heart Association Scientific Sessions 2019 [This study was supported by an award from the Robert Wood Johnson Foundation (74624) and a grant from the National Heart, Lung, and Blood Institute (NHLBI; R01HL141434). The Framingham Heart Study is supported by a contract from NHLBI (PI VSR 75N92019D00031). Investigator time was supported from the following grants: NHLBI R01HL126911 (EJB), NHLBI 2R01 HL092577 (EJB), National Institute on Aging (NIA) 1R01AG066010 (EJB), American Heart Association 18SFRN34110082 (EJB), NHLBI R01HL126911 (DDM), NHLBI R01HL137734 (DDM), NHLBI R01HL137794 (DDM), NHLBI R01HL13660 (DDM), NHLBI U54-HL 143541 (DDM), and NIA 1U01AG068221 (HL). The Apple Watches were provided to Boston University by the Apple Inc at no cost to the study.Conflicts of Interest: DDM has received research support from Apple Inc, Bristol-Myers Squibb, Boehringer-Ingelheim, Pfizer, Flexcon, Samsung, Philips Healthcare, and Biotronik and has received consultancy fees from Heart Rhythm Society, Bristol-Myers Squibb, Pfizer, Flexcon, Boston Biomedical Associates, and Rose Consulting. He also declares financial support for serving on the Steering Committee for the GUARD-AF study (NCT04126486) and Advisory Committee for the Fitbit Heart Study (NCT04176926). JMM was a guest lecturer/consultant for Merck Research Laboratories unrelated to this work. CN is an employee of CareEvolution, Inc, a health care technology company. Apple Inc was not involved in the study design, analysis, interpretation, or reporting of study results. Starting 2020, NLS received funding from Novo Nordisk for an investigator-initiated research grant unrelated to the current study. All other authors declare no other conflicts of interest.Script for contacting previously enrolled electronic Framingham Health Study participants to join the messaging trial.Library of messages used in the trial.Power calculations.Participant characteristic definitions.Characteristics of electronic Framingham Health Study participants using a blood pressure cuff or smartwatch not participating in the trial.Proportion of participants transmitting at least one blood pressure measurement within 7 days of each weekly notification according to age and electronic Framingham Health Study enrollment status.Proportion of participants transmitting at least one heart rate measurement within 7 days of each weekly notification according to age and electronic Framingham Health Study enrollment status.Three-way and two-way interaction analyses for the proportion of participants transmitting at least one blood pressure measurement within 7 days of each weekly notification.Odds ratios from the two-way interaction analyses for the proportion of participants transmitting at least one blood pressure measurement within 7 days of each weekly notification.Longitudinal analysis of the weekly proportion of participants transmitting at least one blood pressure measurement within 7 days of each weekly notification.Proportion of participants transmitting at least one blood pressure measurement within 7 days of each weekly notification in the morning and evening notification groups.Proportion of participants transmitting at least one blood pressure measurement within 7 days of each weekly notification in the weekend and weekday notification groups.Three-way and two-way interaction analyses for the proportion of participants transmitting at least one heart rate measurement within 7 days of each weekly notification.Odds ratios from the two-way interaction analyses for the proportion of participants transmitting at least one heart rate measurement within 7 days of each weekly notification.Longitudinal analysis of the weekly proportion of participants transmitting at least one heart rate measurement within 7 days of each weekly notification.Proportion of participants transmitting at least one heart rate measurement within 7 days of each weekly notification in the morning and evening notification groups.Proportion of participants transmitting at least one heart rate measurement within 7 days of each weekly notification in the weekend and weekday notification groups.Survey completion among 205 individuals who had not been enrolled in the electronic Framingham Health Study prior to the beginning of the messaging trial.CONSORT-eHEALTH checklist (V 1.6.1).