SPECIALTY TOPICS · GUIDE
Digital Biomarkers
What a digital biomarker from a sensor or wearable is, the three-part check (verification, analytical and clinical validation) that shows whether it measures something real, and its limits.
Content last updated . This page has not been medically reviewed.
Back to Emerging Wellness ScienceWhat the term covers
A biomarker is a measurement used as an indicator of a body process or health state. A digital biomarker is one captured by a digital tool, usually a sensor in a wearable, phone or home device, and turned into a number by software. Usage of the term varies. This page follows a widely cited framework that calls such tools biometric monitoring technologies (BioMeTs): connected digital medicine products that process data captured by mobile sensors using algorithms to generate measures of behavioral and/or physiological function [1]. Step counts, sleep estimates, heart-rate patterns and walking speed are examples.A digital measure is not a diagnosis, and a change in it is not automatically a health benefit. This page is education, not medical advice.
Three questions that decide whether a measure can be trusted
The V3 framework separates three checks [1]:| Check | Question | Typical work |
|---|---|---|
| Verification | Does the hardware record the raw signal correctly? | Evaluation of sample-level sensor outputs, on the bench and by computer |
| Analytical validation | Does the software correctly turn the raw signal into a physiological measure? | Testing the processing algorithms in living people |
| Clinical validation | Does the measure identify, measure or predict a meaningful clinical or functional state in a defined population and context? | Studies in groups with and without the condition |
Clinical validation takes a measure that has passed the first two steps and asks whether it can answer a specific clinical question, such as assessing or predicting a condition [1]. The framework stresses a defined "context of use" including the population, so a measure validated in one group is not automatically valid in another [1]. See Clinical Validity and Clinical Utility.
Why researchers are interested
The FDA says portable digital health technologies that can be worn, implanted, ingested or placed in the environment allow real-time data collection from trial participants at home. It lists possible advantages: continuous or frequent measurement, recording clinical features that could not be captured at study visits, and remote data gathering [2]. Its examples include actigraphy (movement sensing), photography and contactless sensors [2].The agency has developed a framework for using these technologies in drug and biological product development [2]. A funding call announced in 2026 aims to compare digital measurements with traditional ones in trials and to develop and test novel digital endpoints [2]. That shows an active research area, not that a given consumer device has been accepted for any medical purpose.
How accurate are consumer wearables?
A systematic review of 158 publications examining nine commercial wearable brands found that in laboratory settings several measured steps accurately, heart rate was more variable, and for energy expenditure no brand was accurate [3]. Accuracy varied by manufacturer and device type, and devices are constantly redesigned, so reviews age quickly [3]. The review's accuracy findings come from laboratory settings, which may differ from daily life. For consumer products see Wearables and Health Trackers.Keeping apart: measure, biomarker, outcome
- Sensor reading: what the device records.
- Digital biomarker: the processed measure derived from it.
- Clinical outcome: how a person feels, functions or survives.
Questions to ask about a digital-biomarker claim
- Was the measure verified, analytically validated and clinically validated, and in people like you?
- Compared with what standard measurement?
- Does the claim name a condition, a population and a context of use?
- Is there evidence that acting on the measure improves health, rather than only tracking it?
- Who funded the study and sells the device?
Frequently asked questions
Is a digital biomarker the same as a medical device approval?
Not automatically. Whether a particular product is cleared or approved for a particular purpose is a regulator's decision about that product, so check with the regulator. For details see Regulatory Status of Digital Health Products. The FDA notes its Digital Health Center of Excellence is a resource on the regulatory status of digital health technologies [2].
What does "validated" mean?
It can mean different things. Under the V3 framework, it should cover verification, analytical validation and clinical validation for a defined context of use [1].
Can my smartwatch diagnose a condition?
This page cannot answer that for any particular device. A diagnosis needs clinical validation for a specific use [1]. Talk with a clinician about symptoms or abnormal readings.
Are wearable heart-rate and step numbers reliable?
In laboratory studies steps were measured accurately by several brands and heart rate varied; energy expenditure estimates were not accurate for any brand reviewed [3].
References
- Goldsack JC, Coravos A, Bakker JP, et al. Verification, analytical validation, and clinical validation (V3): the foundation of determining fit-for-purpose for Biometric Monitoring Technologies (BioMeTs). npj Digit Med 2020. Read 2026-10-22.
- U.S. Food and Drug Administration. Digital Health Technologies (DHTs) for Drug Development. Read 2026-10-22.
- Fuller D, Colwell E, Low J, et al. Reliability and Validity of Commercially Available Wearable Devices for Measuring Steps, Energy Expenditure, and Heart Rate: Systematic Review. JMIR mHealth uHealth 2020. Read 2026-10-22.