Blockchain applications in electronic health records: a systematic review of qualitative and quantitative evidence

There are ongoing challenges with Electronic Health Record (EHR) systems, including ransomware breaches, interoperability issues, inconsistent management of consent, and a lack of patient control over their health information. Blockchain technology has been proposed as a secure, immutable foundation to enhance the security, transparency, and trustworthiness of digital health systems. This systematic review was conducted in accordance with PRISMA 2020 guidelines and was registered prospectively with PROSPERO (CRD420251112379). We conducted Searches in the SCOPUS, Web of Science, and PubMed databases through March 2025. Included studies assessed the impact of blockchain-based EHR system implementations on security, interoperability, performance, and patient-related outcomes. Two authors independently screened, extracted data, and assessed risk of bias. Meta-analyses were conducted using random effects where appropriate, and thematic synthesis was used to explore governance and implementation challenges. Sixteen empirical studies (primarily prototypes and pilots) were included. Among them, common issues were (i) performance and scalability constraints (e.g., latency vs. throughput trade-offs during consensus), (ii) governance and compliance conflicts in regulated environments (e.g., GDPR “right to erasure” vs. immutable ledgers; country-specific applicability of HIPAA/GDPR), (iii) key management and identity life-cycle issues, and (iv) data quality and semantic harmonization issues (e.g., partial coverage of HL7 FHIR and varying use of terms). The quantitative results showed improvements in security-related and interoperability-related outcome measures, but the term “interoperability” was defined differently (e.g., exchange success rate, API response time, or standards compliance). The architectures of blockchain-based EHR systems could improve auditability, access control, and technical communication, particularly when integrated with standards such as HL7 FHIR, although the existing literature is very limited and primarily consists of non-production analyses. The findings are described as tentative, and the value of practical, multi-site research with well-defined outcomes and governance frameworks for consent, deletion/rectification, and cross-jurisdictional compliance is highlighted.