Blockchain can be described as an immutable ledger, logging data entries in a decentralized manner. This new technology has been suggested to disrupt a wide range of data-driven domains, including the health domain. The purpose of this study was to systematically review, assess and synthesize peer-reviewed publications utilizing/proposing to utilize blockchain to improve processes and services in healthcare, health sciences and health education. A structured literature search on the topic was conducted in October 2018 relevant bibliographic databases. 39 publications fulfilled the inclusion criteria. The result indicates that Electronic Health Records and Personal Health Records are the most targeted areas using blockchain technology. Access control, interoperability, provenance and data integrity are all issues that are meant to be improved by blockchain technology in this field. Ethereum and Hyperledger fabric seem to be the most used platforms/frameworks in this domain. This study shows that the endeavors of using blockchain technology in the health domain are increasing exponentially. There are areas within the health domain that potentially could be highly impacted by blockchain technology.

Background: Health care systems are currently undergoing a digital transformation that has been primarily triggered by emerging technologies, such as artificial intelligence, the Internet of Things, 5G, blockchain, and the digital representation of patients using (mobile) sensor devices. One of the results of this transformation is the gradual virtualization of care. Irrespective of the care environment, trust between caregivers and patients is essential for achieving favorable health outcomes. Given the many breaches of information security and patient safety, today’s health information system portfolios do not suffice as infrastructure for establishing and maintaining trust in virtual care environments. Objective: This study aims to establish a theoretical foundation for a complex health care system intervention that aims to exploit a cryptographically secured infrastructure for establishing and maintaining trust in virtualized care environments and, based on this theoretical foundation, present a proof of concept that fulfills the necessary requirements. Methods: This work applies the following framework for the design and evaluation of complex intervention research within health care: a review of the literature and expert consultation for technology forecasting. A proof of concept was developed by following the principles of design science and requirements engineering. Results: This study determined and defined the crucial functional and nonfunctional requirements and principles for enhancing trust between caregivers and patients within a virtualized health care environment. The cornerstone of our architecture is an approach that uses blockchain technology. The proposed decentralized system offers an innovative governance structure for a novel trust model. The presented theoretical design principles are supported by a concrete implementation of an Ethereum-based platform called VerifyMed. Conclusions: A service for enhancing trust in a virtualized health care environment that is built on a public blockchain has a high fit for purpose in Healthcare 4.0.

Background: The increasing usage of various online services requires an efficient digital identity management approach. Unfortunately, the original Internet protocols were not designed with built-in identity management, which creates challenges related to privacy, security, and usability. Thereis an increasing concern regarding the management of these sensitive data in the society, who have access to it and where it is stored. Blockchain technology can, potentially offer a secure solution to address this problem, in a decentralized manner without any centralized authority. This is of importance for e-health services where the patient and the healthcare provider often are required toprove their identity. Blockchain technology can be utilized for creating digital identities and make themanagement of those identities easier, giving a higher degree of control to the user than what current solutions offer. It can be used for creating a digital identity on the blockchain, making it easier to manage for individuals and entities, giving them greater control over who has their personal in-formation and how they handle it, and it could be utilized to create a higher degree of trust andsecurity to e-health applications. Objective The aim of this research work is to review the state-of-the- art regarding blockchain-based decentralized identity management for healthcare applications. Based on this summary, we provide a viewpoint on how blockchain-based decentralized identity frameworks couldbe utilized for virtualized healthcare applications. Method This research has applied a scoping, semi-systematic review approach to summarize thestate-of-the-art. Included identity management systems were evaluated based on seven criteria:Autonomy, Authority, Availability, Approval, Confidentiality, Tenacity and Interoperability ResultsSeven blockchain-based identity management systems were included and evaluated in this work:These include solutions built with Ethereum, Hyperledger Indy, Hyperledger Fabric, Hedera andSovrin blockchains. Conclusion Digital identity management is crucial for virtual healthcare. Decentralized identity management for healthcare purposes is currently being explored, both in academia and the private sector. More work is needed with the aim to improve the efficiency of current DIM solutions and to fully understand what technical frameworks are best suited for e-health applications.

The enormous pressure of the increasing case numbers experienced during the COVID-19 pandemic has given rise to a variety of novel digital systems designed to provide solutions to unprecedented challenges in public health. The field of algorithmic contact tracing, in particular, an area of research that had previously received limited attention, has moved into the spotlight as a crucial factor in containing the pandemic. The use of digital tools to enable more robust and expedited contact tracing and notification, while maintaining privacy and trust in the data generated, is viewed as key to identifying chains of transmission and close contacts, and, consequently, to enabling effective case investigations. Scaling these tools has never been more critical, as global case numbers have exceeded 100 million, as many asymptomatic patients remain undetected, and as COVID-19 variants begin to emerge around the world. In this context, there is increasing attention on blockchain technology as a part of systems for enhanced digital algorithmic contact tracing and reporting. By analyzing the literature that has emerged from this trend, the common characteristics of the designs proposed become apparent. An archetypal system architecture can be derived, taking these characteristics into consideration. However, assessing the utility of this architecture using a recognized evaluation framework shows that the added benefits and features of blockchain technology do not provide significant advantages over conventional centralized systems for algorithmic contact tracing and reporting. From our study, it, therefore, seems that blockchain technology may provide a more significant benefit in other areas of public health beyond contact tracing.

Objectives The objective was to determine the predictive potential of anthropometric indices to screen prevalent diabetes mellitus type 2 in a Norwegian population. Design This is a cross-sectional design to determine the potential association of waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), waist circumference (WC) and body mass index (BMI) with prevalent diabetes mellitus type 2 through logistic regression analysis. Receiver operating characteristic (ROC) curves were used to determine the predictive potential of the anthropometric indices. Youden’s index was applied to determine the optimal cut-off points for each anthropometric index. Setting This study used cross-sectional data from the populations-based Health Study in Nord-Trøndelag which invited all citizens in the county above 20 years of age. Participants This study included all those who were non-pregnant and had complete data (N=50 042), 98.5% of the participants. The sample is to be considered representative for the population of Norway. Primary and secondary outcome measures OR and ROC of the potential association between diabetes mellitus type 2 and anthropometric indices were the main planned and performed outcome measures. Results The results suggest that the anthropometric indices performed differently within the Norwegian population with WHR and WHtR being the stronger predictor with (ROC) of 0.746 (0.735 to 0.757) and 0.741 (0.730 to 0.752). The predictive potential for the investigated anthropometric indices was generally stronger for women than men. Conclusion Anthropometric indices of size BMI and the highly correlated WC are less associated with prevalent diabetes mellitus type 2 than WHR (WC adjusted for hip circumference) or WHtR (WC adjusted for height) in a Norwegian population.