JMIR Publications

ABSTRACT

Background:

New electronic, “e-Cohort” study designs provide resource-effective methods for collecting participant data. It is unclear if implementing an e-Cohort without direct, in-person participant contact can achieve successful participation rates.

Objective:

To compare two distinct implementation strategies for co-enrolling participants from the Framingham Heart Study (FHS) into the FHS-Health eHeart (HeH) Pilot Study, a digital cohort with infrastructure for collecting mHealth data.

Methods:

FHS participants who had an email address and smartphone were randomized to our FHS-HeH pilot study into one of two study arms: remote vs. on-site support. We over-sampled older adults (≥65 years), with a target of enrolling 20% of our sample as older adults. In the remote arm, participants received an email containing a link to enrollment website, and, upon enrollment, were sent four smartphone-connectable sensor devices. Participants in the on-site arm were invited to visit an in-person FHS facility and were provided in-person support for enrollment and connecting the devices. Device data was tracked for at least 5 months.

Results:

Compared to individuals that declined, individuals that consented to our pilot study (n=101 on-site, n=93 remote) were more likely to be women, highly educated, and younger. In the on-site arm, connection and initial use of devices was ≥20% higher than the remote arm (mean percent difference 25% [95% confidence interval, 17-35] for activity monitor, 22% [12-32] for blood pressure cuff, 20% [10-30] for scale, and 43% [30-55] for electrocardiogram), with device connection rates in the on-site arm of 99%, 95%, 95%, and 84%. Once connected, continued device use over the 5 month study period was similar between study arms. Although recruitment of older adults ≥65 years was less efficient than adults <65 years (we consented 50% of those recruited ≥65 years vs. 75% of <65 years), rates of device connection and continued use of devices for 5 months was >70% across devices.

Conclusions:

Our pilot study demonstrated that deployment of mobile devices among middle-aged and older adults in the context of an on-site clinic visit was associated with higher initial rates of device use as compared to offering only remote support. Once connected, device use was similar in both groups.