To identify relevant SLRs focusing on the application of blockchain technology in healthcare, we developed a comprehensive search strategy, which involved a systematic and structured search across various databases and sources to ensure a thorough coverage of the topic.

We conducted searches in several electronic databases recognized for their comprehensive coverage of literature in the fields of technology and healthcare. These included:

PubMed

Additionally, to ensure exhaustive coverage and capture literature that might not be indexed in the aforementioned databases, we conducted supplementary searches in:

Google Scholar

The development of the search strategy involved an integration of specific keywords and Boolean logic. The core search terms employed were “blockchain”, “healthcare”, and “systematic literature review”. These terms were interconnected using Boolean operators. For instance, the search query “blockchain” AND “healthcare” AND “systematic literature review” was utilized. To ensure compatibility with the unique indexing systems and search functionalities of each database, the search queries were customized accordingly. The temporal scope of the search was confined to the period from 2008, marking the publication of Bitcoin’s white paper, to December 2023, the knowledge cutoff date of this study. The retrieved articles were then listed according to their relevance to the search purposes.

As shown in Table 2, the initial results were screened based on titles and abstracts to identify studies that potentially met our inclusion criteria. The inclusion criteria were:

Articles focusing on the application of blockchain in healthcare.

Exclusion criteria included:

Non-peer-reviewed articles.

Then, the duplicates were removed using digital object identifiers (DOIs).

To answer the research question proposed, selected articles underwent a full-text review for detailed analysis. Relevant information was extracted and compiled into a predefined data extraction template, which included:

Study objectives and research questions.

In examining the applicability of blockchain technology for healthcare data sharing, our analysis identified eight critical criteria: scalability, privacy, integrity/immutability, interoperability/accessibility, transparency, patient involvement, legal compliance, and cost/incentive, as shown in Table 3. These criteria, combined with the flowchart by Wüst and Gervais [8], collectively form a comprehensive framework, guiding the evaluation of blockchain’s application in healthcare data sharing.

Determining the suitability of blockchain technology for healthcare applications requires a systematic evaluation of various factors. To address this, we have developed a comprehensive decision-making flowchart, as shown in Figure 2.

The flowchart serves as a valuable tool for healthcare practitioners, facilitating informed decision-making regarding the implementation of blockchain solutions. It encompasses factors such as the requirements of data sharing, data integrity, and immutability, the identity verification and trustworthiness of healthcare actors, patient involvement, and public verifiability. Each step of the flowchart is accompanied by three elements, a rationale, term definitions, and a decision pathway. The rationale explicates the purpose of each step, ensuring that stakeholders understand the importance of the considerations involved. Term definitions are provided to clarify technical and healthcare-specific terminology, catering, especially to practitioners less familiar with blockchain technology. Finally, the decision pathway guides users to subsequent steps based on their specific circumstances and requirements.

1.

Rationale

This initial question focuses on the necessity of data sharing. It serves as the primary filter for assessing the applicability of blockchain in the health domain.

1.

Rationale

This step examines the necessity of trusted third parties in traditional and centralized healthcare data sharing systems [68], such as hospitals, insurance companies, and government agencies. It directly confronts the scalability challenge of transitioning traditional, centralized healthcare data sharing to a decentralized blockchain approach [21, 51, 52]. This step also prompts an evaluation of whether the existing infrastructure, predominantly based on trusted third parties, meets the demands of healthcare data sharing. It invites stakeholders to assess the scalability challenge of current blockchain technology. The decision to integrate blockchain in healthcare should consider scale and balance the benefits of decentralization against the established trust in centralized systems.

1.

Rationale

In this step, data integrity and immutability ascend to paramount importance [57, 63, 65]. This step prompts stakeholders to consider whether the existing data sharing mechanisms afford sufficient control over the data’s integrity once it is out of their direct custody. It challenges them to evaluate if traditional systems offer adequate safeguards against unauthorized alterations, deletions, or breaches.

1.

Rationale

Transparency is not just a preference but a necessity in modern healthcare data management [69, 70]. It fosters trust among stakeholders [63] and aids in compliance with regulatory standards [48]. Given the sensitive nature of healthcare data, stakeholders must be assured that the data is handled appropriately and that activities are traceable and accountable [55].

1.

Rationale

In healthcare scenarios where the identities of the actors are known, the data sharing is typically limited to a few organizations identifying a solution to share information. In other health scenarios, the identities of the actors are not well known due to a need for information sharing across multiple organizations. In this later case, the information is generated or collected in different technical systems thereby, interoperability becomes an important concept linked to this question. Therefore, identifying actors within a data-sharing network aligns with ensuring interoperability, which is significant in healthcare [71, 72]. Interoperability, in this context, refers to the ability of different entities to communicate, exchange data, and use the information that has been exchanged efficiently and effectively based on the identification of healthcare actors [73]. This step underscores the importance of interoperable systems in ensuring that the identities of all participants in the healthcare data sharing process are accurately known and verifiable. The level of identity disclosure directly impacts the appropriate blockchain type [74].

1.

Rationale

Trust among actors in a healthcare data-sharing context is important to ensure that the data is not misused and that all parties adhere to the agreed-upon protocols and ethical standards. In a blockchain network, trust can be related to confidence in the actors’ behavior and the security of the transactions [24, 75]. The level of trust among the actors will influence the governance model and the degree of decentralization appropriate for the blockchain system [6, 76].

1.

Rationale

In healthcare, patient-centric care models are increasingly important, and involving patients in their data management is a key aspect of this [77]. Patient involvement can empower individuals to take control of their health information, allowing them to grant or revoke access to their data [78, 79]. Blockchain can offer a platform where patients can actively engage with their data securely and transparently [80].

1.

Rationale

Cost is a significant consideration for healthcare organizations when integrating blockchain technology, which can vary widely depending on the network type and the implementation scale [4]. The decision balances the financial resources available with the benefits a blockchain solution could provide.

1.

Rationale

Public verifiability is an important factor in the choice of blockchain architecture, especially in the healthcare sector, where the integrity of data and the accountability of actors are subject to scrutiny by external parties [54, 67]. In such scenarios, the blockchain’s inherent audibility feature becomes invaluable, as it provides a tamper-proof ledger where all transactions are recorded in a manner that is secure and accessible for verification purposes. The decision here will largely depend on the nature of the data being shared and the broader objectives of the healthcare organization regarding public trust and accountability [8].

To evaluate the utility of our decision-making flowchart in guiding blockchain implementation decisions within the healthcare sector, we analyze MedRec [27], Drugledger [28], iWellChain [82], DACIL [83], REALM [84], ChainSure [32], and LUCE [85], as shown in Table 4. In this table, the category column classifies each project into functional areas. The case description provides brief summaries of each project’s objectives. Assumptions detail the underlying premises for each project’s evaluation, focusing on aspects like data privacy and cost distribution. The decision path outlines the step-by-step choices made based on the decision-making flowchart, indicating decisions with ‘Yes’ or ‘No’. Finally, the final outcome column shows the type of blockchain technology adopted by each project. Detailed analysis can be found in Supplementary material.

To have a more comparative understanding of our decision-making framework, we integrate the case studies into the original flowchart, as shown in Figure 3. The color-coded paths indicate different routes that can be taken depending on the answers to the yes/no questions at each decision point. These paths represent distinct case studies, each with unique considerations and endpoints.

The findings of this review, resulting in a decision-making flowchart for determining the suitability of blockchain in healthcare applications, have significant implications for healthcare professionals and policymakers.

For healthcare professionals, the flowchart serves as a valuable tool for assessing the potential benefits and challenges of integrating blockchain into their practice. It guides them in considering factors such as the necessity of data sharing, trusted third parties, date immutability and integrity, participant knowledge, patient involvement, and public verifiability. By leveraging blockchain technology in appropriate scenarios, healthcare professionals can enhance data security and privacy, improve interoperability, and enhance patient care coordination [3]. Understanding the conditions under which blockchain is most likely to yield positive outcomes is essential for effective utilization by healthcare professionals.

Policymakers can also benefit from the insights provided by this study to develop appropriate regulations and guidelines regarding the implementation of blockchain in healthcare. The flowchart offers policymakers a comprehensive understanding of the factors to consider when assessing the feasibility associated with adopting blockchain technology. Policymakers can utilize this information to shape policies that support innovation while ensuring privacy, security, and ethical use of blockchain in healthcare. Additionally, they can address legal and regulatory challenges that may arise, promoting responsible and effective integration of blockchain in the healthcare ecosystem [86].

This review has also identified gaps and areas for future research in the healthcare blockchain field. While the literature on this topic has expanded, certain aspects require further investigation.

Firstly, more empirical studies are needed to evaluate blockchain solutions’ actual implementation and impact in real-world healthcare settings. While existing literature provides theoretical insights and frameworks, empirical evidence of blockchain applications’ effectiveness, efficiency, and user experiences in healthcare is limited. Future research should focus on conducting expert interviews, stakeholder surveys, and pilot projects to assess the practical implications, challenges, and benefits of implementing blockchain technology across various healthcare domains and organizational contexts.

Secondly, blockchain’s ethical, legal, and social implications in healthcare require further exploration. As blockchain technology becomes more prevalent in healthcare, examining ethical considerations related to patient privacy, data ownership, consent management, and data governance is crucial. Additionally, legal and regulatory frameworks should be developed to address unique challenges posed by blockchain, such as jurisdictional issues, liability, and dispute resolution. Future research should provide comprehensive guidance on the ethical and legal aspects of blockchain implementation, facilitating responsible and transparent use of the technology in healthcare.

Furthermore, as the volume and complexity of healthcare data continue to rise, the scalability of blockchain solutions becomes a critical concern. Scalability in this context refers to the ability of blockchain networks to handle increasing amounts of data without compromising on speed or efficiency. Efficient data processing is crucial in healthcare, where real-time data availability can significantly impact patient care and outcomes. Future research needs to focus on enhancing the scalability of these networks through innovative approaches such as sharding, which divides the network into smaller, more manageable segments, or through layer two solutions that process transactions off the main blockchain to decrease load and increase speed. This will ensure that as healthcare data grows, blockchain networks remain efficient and responsive to the needs of the industry.

Lastly, interoperability between blockchain platforms and existing healthcare systems is critical for successfully adopting and implementing blockchain technology in healthcare. This interoperability involves the seamless integration and exchange of data across different blockchain platforms, blockchain networks, and legacy healthcare systems. The challenge lies in creating a standardized framework for secure, reliable, and efficient data exchange. Future studies should explore the development of technical solutions and standards that facilitate this integration. Adopting common standards can significantly enhance the potential for blockchain to support diverse healthcare applications, from patient records management to supply chain transparency, thereby improving healthcare delivery.

Despite employing a rigorous methodology, this review has some limitations. Firstly, it relies on existing SLRs as the primary source of information, which may vary in quality and coverage. To address this, future studies could consider incorporating primary research studies to complement findings from SLRs.

Secondly, the validation of the decision-making flowchart is currently conducted using case studies, primarily due to constraints in time and resources. To enhance the validity of the flowchart in future iterations, future studies should incorporate a broader range of methods, such as expert interviews, stakeholder surveys, and pilot projects. These additional methods will gather diverse perspectives and more comprehensive feedback, contributing significantly to developing a more robust and reliable decision-making tool.

Lastly, the decision-making flowchart presented in this study is based on synthesizing existing literature. It may not capture all possible factors or considerations relevant to specific healthcare contexts. Therefore, healthcare professionals and policymakers should contextualize the flowchart within their unique organizational settings and critically reflect before making decisions about adopting blockchain technology.

In conclusion, this tertiary review underscores the potential benefits and complexities of integrating blockchain technology in healthcare. The study developed and validated a decision-making flowchart to assist healthcare professionals and policymakers in making informed decisions about blockchain applications in healthcare. The flowchart, tested through various case studies, offers a structured approach to evaluating the viability and implications of blockchain technology. Our findings stress the necessity of assessing key factors such as scalability, privacy, interoperability, and legal compliance to harness blockchain’s benefits effectively. The inclusion of practical case studies confirms the applicability of the decision-making tool across various healthcare domains, promoting a responsible and informed approach to adopting blockchain technology in the healthcare sector.