Medical research is continuously evolving, with new tools reshaping how health and disease are measured. Among these advancements are digital biomarkers, which are objective, quantifiable health data collected by digital devices like smartphones and smartwatches. Unlike intermittent data points gathered in a clinic, digital biomarkers provide a continuous stream of information from a person’s daily life. This capability is leading to their growing use in clinical trials to better understand patient health.
The Role of Digital Biomarkers in Modern Research
Digital biomarkers are shifting research from snapshots of health to a continuous view. Traditional biomarkers, like a blood pressure measurement taken at a doctor’s appointment, provide a single data point. This measurement might not accurately reflect a person’s blood pressure throughout their day. Digital tools, however, capture physiological and behavioral data continuously in a patient’s own environment.
This constant data collection offers a more complete picture of an individual’s health status between clinic visits. For instance, a smartwatch can monitor a person’s heart rate throughout the day and night, providing a rich dataset that shows fluctuations with activity, stress, and sleep. This contrasts with a single electrocardiogram reading in a medical facility. The ability to gather information passively helps ensure the data reflects a real-world condition.
This approach is proving valuable across different areas of medicine. In studies of neurological conditions like multiple sclerosis, sensors can track subtle changes in a person’s gait and balance over time. For individuals with depression, smartphone apps can monitor sleep patterns, social interactions, and physical activity levels. These digital signals provide objective indicators of a person’s mental state, complementing traditional self-reported questionnaires.
Enhancing Clinical Trial Endpoints and Data
In clinical trials, digital biomarkers are refining how the effectiveness of new therapies is measured. A central component of any clinical trial is its “endpoint,” which is a specific outcome used to determine whether a treatment is working. Digital biomarkers can function as these endpoints, offering precision and objectivity that can be difficult to achieve with conventional methods.
The use of digital tools can make these endpoints more sensitive. In clinical trials for Parkinson’s disease, the accelerometer and gyroscope in a smartphone can quantify the severity and frequency of tremors. Patients might be asked to perform specific tasks, like holding the phone, while the sensors record movement data. This provides an objective measure of motor symptoms that is less susceptible to subjective interpretation.
This technology can also capture data that was previously hard to collect. For a new drug treating a respiratory condition, a sensor’s microphone could count cough frequency throughout the day and night. In studies involving older adults, GPS and accelerometer data from a wearable device can assess “life-space mobility,” the extent to which a person moves through their home and community. This can be a meaningful indicator of functional independence.
By providing such objective data, digital biomarkers can help reduce the placebo effect. This may also allow for smaller or shorter clinical trials.
Implementation and Technological Considerations
The practical application of digital biomarkers relies on technologies designed to capture health data from daily life. These tools include wearables, smartphone applications, and ambient sensors. Wearable devices like smartwatches and fitness trackers are equipped with sensors that can track metrics such as heart rate, activity levels, and sleep duration. These are often used for continuous, passive data collection.
Smartphone applications can utilize the phone’s built-in sensors, such as the accelerometer, GPS, and microphone, to track movement, location patterns, and voice characteristics. Data collection through smartphones can be either passive, like tracking step count, or active. Active collection requires the user to perform a specific task, such as a cognitive test or a guided finger-tapping exercise.
Beyond devices carried by individuals, ambient sensors placed in the home can also gather relevant data. These might include sensors on doors to monitor daily activities or bed sensors that track sleep quality. Regardless of the technology used, a secure data pipeline is a fundamental requirement. This system ensures information is transmitted securely to a centralized platform for analysis, while protecting patient privacy.
Navigating Regulatory and Validation Pathways
For a digital biomarker to be accepted as a valid measure in a clinical trial supporting drug approval, it must undergo a rigorous validation process. This process has two main stages: analytical validation and clinical validation. These steps are necessary to gain acceptance from regulatory bodies like the U.S. Food and Drug Administration (FDA).
Analytical validation focuses on the technology itself. It asks whether the digital tool accurately and reliably measures what it is intended to measure. For example, a wearable device designed to measure heart rate is tested to confirm its readings are precise when compared to a medical-grade electrocardiogram (ECG). This ensures the data being collected is trustworthy.
Following analytical validation is clinical validation, which addresses whether the measurement is meaningful in a medical context. This stage seeks to establish a clear connection between the digital biomarker and a relevant clinical outcome. For instance, clinical validation would determine if a decrease in step count is associated with worsening symptoms in patients with chronic obstructive pulmonary disease (COPD). The FDA provides guidance for Digital Health Technologies (DHTs) to help steer this process.
Beyond validation, ensuring patient privacy and data security is a high priority. This often requires compliance with regulations like the Health Insurance Portability and Accountability Act (HIPAA) to protect sensitive health information.