Title : From paper to chain: A participant-centered econsent model for digital health research supported by blockchain
Abstract:
Background: Informed consent is a fundamental ethical and legal requirement in health research. In digital health research, paper-based consent workflows are poorly aligned with digital study execution, generating fragmented, difficult-to-audit records that inadequately support participant withdrawal rights in multi-actor data processing environments (De Sutter et al., 2023; Yusof et al., 2022). Blockchain-based eConsent has the potential to address these limitations by providing immutable, participant-accessible consent records with programmable lifecycle management; however, limited evidence exists on end-to-end participant-centered implementations in digital health research, and GDPR compliance strategies for on-chain consent records remain empirically unresolved (Kakarlapudi & Mahmoud, 2021).
Objective: To design and validate a participant-centered eConsent model for observational digital health research, integrating blockchain-based audit, GDPR-compliant data governance, and accessible digital interfaces, and to evaluate its feasibility through a real- world pilot study.
Methods: A design science research approach (Hevner et al., 2004) was employed with the Worthmed platform and BioGHP to define and operationalize a digital informed consent for a pilot digital health study. Worthmed enables clinical researchers to design studies and enroll participants, while participants provide their consent and report Patient-Reported Outcome Measures (PROMs) through a WhatsApp chatbot. BioGHP provides a blockchain infrastructure for securely registering consent provision and withdrawal. eConsent design principles were derived from applicable ethical and regulatory frameworks and translated into verifiable requirements for participant information, consent provision, consent traceability, and withdrawal management. In the proposed flow, participants receive a secure WhatsApp link that directs them to a Worthmed-hosted eConsent interface, where study information is presented in a structured, accessible format before consent is provided. Once consent is submitted, the consent status is registered through the Clinical Study Participation Agreement (CSPA), a smart contract that enables the management of consent status over time. To support data protection requirements, personal data remains stored off-chain within Worthmed, while only pseudonymized identifiers, consent status, and timestamps are recorded on-chain. Validation will be conducted through a prospective observational pilot study with at least 30 participants at the University of Évora (Portugal).
Results: At the time of abstract submission, the eConsent model, blockchain-based consent architecture, and participant-facing digital interface have been designed and are being prepared for pilot validation. The implemented flow will enable participants to access a secure consent interface via WhatsApp, provide explicit consent, and have their consent status registered on-chain. The same interface supports revocation, which is designed to trigger an on-chain status update and suspension of subsequent data collection, in line with GDPR Art. 7(3). By the time of conference presentation, pilot results from the prospective observational study are expected to be available and will include feasibility outcomes related to participant enrolment, completion of the eConsent process, revocation/re- consent functionality, system usability, and operational integration within the Worthmed platform.
Conclusions: This work proposes a participant-centered eConsent model that integrates blockchain with data privacy-compliant, multi-actor data governance for digital health research. The architecture requires no account creation for study participants and supports frictionless consent revocation, thus aiming to advance the evidence base for scalable digital health research infrastructure.
