gms | German Medical Science

Background/research question: Biomarkers are objective measures used to predict or correlate with feelings, functions, and survival of patients. These measurements contribute as indicators for assessing the existence and progression of illnesses and health outcomes. Technological devices such as wearables, sensors, and virtual assistants provide an opportunity to gather data that may be used as digital biomarkers, providing a viable and quickly evolving alternative to conventional biomarkers [1]. Since there is no clear consensus on definitions and standards for the use of digital biomarkers, we aimed at mapping the definitions, features, and application of digital biomarkers in biomedical research.

Methods: We collected all PubMed-indexed publications that refer to “digital biomarker*” in title, abstract, or keywords with no restriction on the publication year. We considered all types of studies and opinion-based articles for eligibility; we only excluded animal-related research. Structured data extraction on study type, used definitions, and features of digital biomarkers and their application was performed by one reviewer and double-checked by another. We described the most influential literature in the field using thematic categorization of definitions and citation analyses, and the key features of studies assessing digital biomarkers.

Results: We identified a total of 324 eligible publications in PubMed that were published between 2014 and 2022 of which 69 are reviews (all types, i.e., systematic, or not), 215 are primary research, and 40 were classified as others (opinions, perspectives, and editorials). One-hundred and forty articles (43%) provided a definition of digital biomarkers: 90 articles (28%) provided a definition without considering any reference, and 50 (15%) a definition with reference. The final results will be available in winter 2022/2023 and presented at the conference.

Conclusion: An expected value of our work is to show the available definitions, features, and application of digital biomarkers. Our preliminary results point to a variability of definitions for digital biomarkers indicating that authors have attempted to create their own concept and give an identity to this type of biomarker. There is an increasing need for an official concept and guidelines which can unify, regulate, and prevent any confusion with the terms.

Competing interests: RC2NB (Research Center for Clinical Neuroimmunology and Neuroscience Basel) is supported by Foundation Clinical Neuroimmunology and Neuroscience Basel. All authors declare no competing interests.