Smartwatches Provide Wealth of Data for Research and Patient Care, Study Finds

A University of Michigan study shows how wearable devices such as the Apple watch offer a window into the daily lives of thousands, offering valuable research and clinical information.

Millions use wearable devices to track how much they’ve walked, but smartwatches can also yield incredibly valuable information about the health of large groups of people.

A University of Michigan study tracking thousands of people offers some insights. The study, conducted over three years, collected data on more than 6,000 people wearing Apple watches.

The devices provide a wealth of information on the baseline health of thousands of people and could be of immense value to healthcare providers. The study was published in The Lancet Digital Health.

Mobile technologies such as wearable devices can offer “a window into individuals’ daily lives and an opportunity to engage users in tracking and managing their health,” the authors write.

Too little is known about how everyday life and chronic disease eventually develop into health emergencies, the study’s authors note. Getting an understanding of the daily life of larger groups can yield much more information for health care systems.

Mobile devices offer precisely that opportunity. Most Americans have a mobile device of some form, with eight in 10 Americans using a smartphone. And one in three Americans owns a smartwatch.

“From both a research and clinical standpoint, as we design digital health interventions or make recommendations for our patients, it’s important to understand patients’ baseline activity levels,” Dr. Jessica Golbus of University of Michigan Health’s Division of Cardiovascular Medicine, a co-investigator on the study, said in a news release.

The study tracked more than 6,400 participants from varying backgrounds. Women made up 54% of the study group, compared to 46% of men. In addition, 17% of the participants were Asian and another 17% were Black. The participants had a median age of 48; about 18% were 65 years and older.

And the study looked at people with varying health conditions: one in three had hypertension, 27% were battling depression and 10% had diabetes.

The authors said the study could offer important information on the impact of COVID-19, since they’ve collected a wealth of data from participants before the emergence of the pandemic.

“We have data on participants both before and after the onset of the pandemic, so we really have the capability to evaluate how physiologic parameters changed over the course of the pandemic both as a result of illness but also due the global impact the pandemic has had on all of our lifestyles,” Golbus said in the news release.

Participants wore their Apple Watch for an average of 15.5 hours a day. The study collected more than 200 million heart rate measurements via the Apple Watch and an additional 1.1 million blood pressure readings with the Omron blood pressure cuff.

On average, women had resting hearts 3 beats per minute higher than men. Those 65 and older had substantially lower resting and walking heart rates.

Black participants had the highest heart rates and those who were white had the lowest rates, the study found. Black participants also had higher blood pressure readings than other groups.

Participants walked about 7,500 steps per day, with men walking a bit more (447 more steps on average), the study found.

The study did find differences in activity tracked with watches versus smartphones, with the phones typically underestimating step counts compared to watches.

The study is dubbed MIPACT - Michigan Predictive Activity & Clinical Trajectories – and was done in collaboration with Apple.