Alexandre Chan
“Despite the promise of applying wearable device technology in medical research, there is still a lack of standardization in the medical literature regarding the analysis and reporting of adherence, validity and physical activity data being generated,” says the study’s corresponding author, Alexandre Chan, UCI chair and professor of clinical pharmacy practice. “To address this issue, we have curated a set of recommendations to guide researchers on the minimum reporting threshold for key metrics.” School of Pharmacy & Pharmaceutical Sciences / UCI

Irvine, Calif., Feb. 16, 2022 — Wearable activity trackers are not only popular with consumers but also commonly employed by clinicians for both real-time and remote monitoring of patients’ physical fitness. When these devices are used as healthcare monitoring tools in medical research studies, however, there’s an issue: inconsistency. To help remedy this, a team led by University of California, Irvine researchers has developed a framework for standardizing data collection and reporting.

The study was recently published online in the International Journal of Medical Informatics.

“Activity trackers capture personalized data that can provide insights in healthcare analytics and user feedback on health status, for both patients and healthy individuals, but there’s a lack of standardization in reporting on the metrics they generate,” said corresponding author Alexandre Chan, UCI chair and professor of clinical pharmacy practice. “These devices may revolutionize healthcare by allowing researchers to monitor symptom severity and assist clinicians in providing their patients more holistic care and, ultimately, improve people’s quality of life, but the biometric statistics obtained can be highly variable. Our aim is to improve the consistency of reporting.”

The researchers’ recommendations provide a minimum threshold framework for reporting adherence, validity and physical activity measures in clinical studies.

Several commercial trackers have been used in medical research, with the Fitbit being the most common. Brands integrate different sensors – such as accelerometers, global positioning systems and gyroscopes – into the devices, and various algorithms are used to determine activity outputs, including step count, distance traveled and sleep patterns. These personal biometrics are input into each individual’s specific account, which can then be accessed directly or through third-party fitness applications.

The team conducted a systematic review of observational or intervention medical research studies of both healthy and patient populations via the PubMed and Embase databases. Although inconsistencies were found in measurement and reporting data, commonalities and definitions of the types of activity tracker-derived measures were identified to develop recommended minimum reporting thresholds. Key metrics were adherence data, or the percentage of days the trackers were worn; validity period, or the adequate wear time per day and per week; and physical activity measures, including step count, acceleration levels, energy expenditure and intensity.

“With the growing use of activity trackers in clinical research, our framework may help facilitate the development of standardized data collection and reporting. Our recommendations are the first step. Currently, we’re applying our recommendations to a set of medical tracker data that we’ve collected from an international study involving adolescent and young adult cancer patients and volunteers. Future studies will need to evaluate the feasibility of adopting minimum reporting thresholds for data generated by these wearable devices,” Chan said.

The research team also included Daniella Chan, a UCI pharmaceutical sciences student; and student Hui Lee, research fellow Chiu Chin Ng and research assistant Angie Hui Ling Yeo of the National University of Singapore’s Department of Pharmacy at the time of the study.

About UCI’s Brilliant Future campaign: Publicly launched on Oct. 4, 2019, the Brilliant Future campaign aims to raise awareness and support for UCI. By engaging 75,000 alumni and garnering $2 billion in philanthropic investment, UCI seeks to reach new heights of excellence in student success, health and wellness, research and more. The School of Pharmacy & Pharmaceutical Sciences plays a vital role in the success of the campaign. Learn more by visiting

About the University of California, Irvine: Founded in 1965, UCI is the youngest member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UCI, visit

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