Dive Brief:

• Four smartphone-based coaching interventions got people on their feet and boosted average daily step counts in a study funded by the Stanford Data Science Initiative and published this month in The Lancet Digital Health journal.
• The data, a subset of the MyHeart Counts Cardiovascular Health Study, was collected via participants' Apple iPhones. The results suggest e-coaching programs can work to motivate short-term increases in daily physical activity, the researchers said. 
• However, a low retention rate for participants and a significant drop in interaction with the app as the study progressed revealed shortcomings. 

Dive Insight:

Most U.S. adults do not get the recommended 150 minutes of weekly exercise, raising risks for cardiovascular disease, metabolic syndrome and depression. Doctors are eager to see their patients become more active, while consumers have indicated a desire to take charge of their health.

Increasing step counts is one way to achieve those goals. Walking has been shown to improve cardiovascular health biomarkers, reduce incidence of hypertension and lower body mass index.

But doctors also are wary of the clinical applications of data that patients are collecting via consumer wearables that are not reviewed by FDA. Speaking at a HIMSS panel earlier this year, Karl Poterack, Mayo Clinic's medical director of applied clinical informatics, said physicians have concerns about the usefulness of wearables data in predicting clinical outcomes and pointed to a lack of high-quality research on the subject.

The MyApp sub-study looked at four different interventions to gauge their effect on participants’ daily step counts: prompts to complete 10,000 steps a day, hourly reminders to stand after one hour of sitting, instructions to read American Heart Association (AHA) guidelines, or individualized e-coaching based on the user’s activity patterns. All four strategies increased average daily step counts by amounts ranging from 226 steps for the 10,000 daily steps group to 319 steps for the AHA prompt group.

Digital studies hold the potential to improve medical research because they are much cheaper and less labor intensive to conduct than clinical trials. Such studies reduce barriers to entry for individuals participating in research. However, the MyHeart Counts researchers noted that their study was not representative of the general U.S. population. Most participants in the study were men (73.5%), and 86.6% of those who reported ethnicity identified themselves as white. The participants also tended to be younger and highly educated.

Another limitation of the study was a high dropout rate, similar to other studies using an e-recruitment process, the researchers said. Only 493 individuals, or 17% of the initial group of participants who enrolled in the study, completed the full set of four interventions, and some of the users did not open the app daily, resulting in missing data.