"The groundwork of all happiness is health." - Leigh Hunt

How your smartwatch could help uncover secrets of disease

September 1, 2023 – The way forward for public health may very well be in your hands – or more specifically, in your wrist.

Researchers are using smartwatches and fitness trackers to conduct large-scale studies that might have been inconceivable previously. It is a growing trend that may significantly increase our knowledge of a spread of diseases.

“There is truly no disease that cannot be touched by this type of research,” said Calum MacRae, MD, PhD, vice chair of scientific innovation within the Department of Medicine at Brigham and Women's Hospital.

Wearables are already getting used to review cardiac, respiratory, neurological and liver diseases, in addition to gynecological diseases, certain cancers, diabetes, sleep quality, autism and mental illnesses.

In a recent example, as much as 1 million iPhone and smartwatch users can log in to share data about their menstrual cycle and other health and lifestyle aspects reminiscent of sleep and stress. 100,000 have already registered for it Apple study on women's healtha 10-year project between Harvard, Apple and the National Institute of Environmental Health Sciences (NIEHS) that's unprecedented in size and scope.

Doctors know that an irregular menstrual cycle is usually a sign of many things, from infertility to heart disease, diabetes and even cancer. Many doctors imagine that menstrual history ought to be considered a vital sign like pulse or blood pressure, but they are saying menstrual and reproductive health is woefully underfunded and under-researched.

With a bigger and more diverse sample of individuals studied, researchers hope to advance the diagnosis and treatment of health conditions related to menstrual cycle disorders.

“We are able to ask questions that we couldn't ask before,” said Shruthi Mahalingaiah, MD, considered one of the study's principal investigators and assistant professor of environmental, reproductive and ladies's health on the Harvard TH Chan School of Public Health.

Rise of wearables

According to a study, almost half of Americans wear smartwatches or fitness trackers Survey 2022. Beyond calories burned and steps taken, the technology can provide information on respiration rate, heart rate, blood oxygen levels and sleep duration via smartphone apps.

Academic medical centers work with digital giants like Apple, Google, Samsung, Alphabet and Amazon, in addition to technology startups and nonprofits. The coronavirus pandemic accelerated the trend as medical facilities tested wearables to observe patients from home. Symptom checkers and outbreak apps helped monitor infection risk and discover hotspots, showing how large data sets might be collected in a consistent way.

Studies using wearables to gather data account for lower than 1% of all studies worldwide. But that number is growing, increasing by several hundred in recent times, in accordance with Clinicaltrials.gov (the National Library of Medicine's clinical trials registry).

This trend goes beyond the wrist to incorporate “smart” glasses, rings, necklaces, “hearables” and even clothing. And the growing universe of medical-grade wearables helps, too: smart patches that track vital signs, blood pressure monitors and continuous glucose monitors, which are sometimes prescribed by doctors but are also available in retail stores.

“You can live anywhere in the country and participate in research using wearables,” said Dr. Ray Dorsey, professor of neurology on the Center for Health Technology on the University of Rochester Medical Center in New York. Previously, volunteers needed to travel to medical centers for testing and updates, which regularly limited the scope of studies.

Big technology, big studies

In recent years, technology corporations reminiscent of Apple, Samsung and Google have introduced and refined open source platforms that allow researchers to develop apps and tools that securely collect health information from people using wearables.

In 2015, a smartphone app developed by Dorsey's URMC team and partners used Apple's ResearchKit in a Parkinson's study. The researchers recruited over 2,000 volunteers in at some point, an unprecedented number on the time. Ultimately, the study involved over 9,000 people completing tasks reminiscent of walking to measure gait changes. The published results helped researchers higher understand how Parkinson's symptoms vary from everyday, Dorsey said.

In 2017, in partnership with Stanford University School of Medicine, the Apple Heart Study enrolled greater than 400,000 Apple Watch users from all 50 states in only 8 months. The study showed that smartwatches can detect irregular heart rhythms reminiscent of atrial fibrillation. Along with a second study, it also paved the best way for the FDA to categorise the watchesElectrocardiogram (ECG) app as a medical device. Since then, smartwatch ECG apps from Fitbit, Samsung and Garmin have received similar clearances.

The Apple Women's Health Study was launched in 2019 together with two other ambitious projects: the Apple Heart and Movement Study, led by MacRae at Brigham and Women's Hospital, with the American Heart Association; and the Apple Hearing Study on the University of Michigan.

The Apple Women's Health study captures a more diverse group of individuals by race, ethnicity, age, socioeconomic position and placement in comparison with previous studies. The data collected pertains to exercise, sleep, and environmental and behavioral aspects, and monthly surveys capture personal data that the sensors cannot capture.

“This gives us the opportunity to consider very detailed information in our analyses,” said Huichu Li, PhD, co-author of the study and a research fellow on the Harvard School of Public Health.

One of the primary findings: It was found that the marginally longer menstrual cycles that might be brought on by COVID vaccines are temporary in nature. More generally, irregular and infrequent periods were found to be more common within the black and Asian people studied, while menstrual cycles were longer in Asian, Hispanic and obese people.

An evaluation of over 50,000 people provided insights into links between abnormal periods and health conditions reminiscent of polycystic ovary syndrome, endometrial hyperplasia and cancer.

“Future studies will delve deeper into the data and examine the effects of environmental influences, behavior and stress on the menstrual cycle,” said Mahalingaiah.

Challenges and the long run

The promise of wearables is marred by challenges. Much more testing is required to make sure the devices provide clinical-quality data. Concerns about privacy and cybersecurity threats remain within the healthcare industry, in accordance with a study by skilled services firm Deloitte.

These recent kinds of studies have limitations. People must own smartwatches and smartphones, technologies which might be less common amongst underrepresented and rural populations, and so they must have reliable web access.

But increasing adoption of the devices — amongst consumers and healthcare providers — means the trend is prone to grow.

“I don’t see a world where this type of research slows down,” said Urvi Shah, senior manager in life sciences and health care at Deloitte Consulting.