Citation: Ghosh, P.K.; Chakraborty, A.; Hasan, M.; Rashid, K.; Siddique, A.H. Blockchain Application in Healthcare Systems: A Review. Systems 2023, 11, 38. https:// doi.org/10.3390/systems11010038 Academic Editor: William T. Scherer Received: 21 November 2022 Revised: 1 January 2023 Accepted: 4 January 2023 Published: 8 January 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). systems Review Blockchain Application in Healthcare Systems: A Review Pranto Kumar Ghosh 1 , Arindom Chakraborty 2 , Mehedi Hasan 3 , Khalid Rashid 4, * and Abdul Hasib Siddique 5 1 Department of Electrical and Computer Engineering, North South University, Dhaka 1229, Bangladesh 2 Department of Electrical and Electronic Engineering, University of Science and Technology Chittagong, Chattogram 4202, Bangladesh 3 Department of Electrical and Computer Engineering, University of Maryland-College Park, College Park, MD 20740, USA 4 Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA 5 Department of Electrical and Electronic Engineering, International University of Scholars, Dhaka 1212, Bangladesh * Correspondence: khalidr@udel.edu Abstract: In the recent years, blockchain technology has gained significant attention in the healthcare sector. It has the potential to alleviate a wide variety of major difficulties in electronic health record systems. This study presents an elaborate overview of the existing research works on blockchain applications in the healthcare industry. This paper evaluates 144 articles that discuss the importance and limits of using blockchain technologies to improve healthcare operations. The objective is to demonstrate the technology’s potential uses and highlight the difficulties and possible sectors for future blockchain research in the healthcare domain. The paper starts with an extensive background study of blockchain and its features. Then, the paper focuses on providing an extensive literature review of the selected articles to highlight the current research themes in blockchain-based healthcare systems. After that, major application areas along with the solutions provided by blockchain in healthcare systems are pointed out. Finally, a discussion section provides insight into the limitations, challenges and future research directions. Keywords: healthcare; blockchain; health record; patient monitoring; medical data security 1. Introduction High maintenance and management costs are the dire problems that modern health- care systems face [1]. The healthcare system is highly complex, containing several domains, each comprising physicians, researchers, practitioners, supportive staff, management em- ployees, and patients [2]. As a result, categorization and management of patient data becomes a daunting challenge [3,4]. This challenge is further exacerbated by dissimilar data structures and disparate workflows in different healthcare domains. For these reasons, the lack of efficient interchange of healthcare-related information among various healthcare domains poses a great hindrance [5]. To tackle health information records and exchange, a system is required to be devel- oped, managed, and maintained. A third party develops and maintains traditional personal health record and electronic health record systems, with trust, privacy, and data security remaining important challenges [6]. However, the third-party-based existing healthcare recording systems cannot satisfy stakeholders’ privacy needs [7]. As a result, the traditional electronic healthcare model lacks transparency because of privacy and data security issues. In resolving the security-related concerns and the severe problem of enormous and highly diverse data in healthcare systems, blockchain technology offers significant prospects [8]. Blockchain is a decentralized, distributed database, peer-to-peer network, and digital ledger [9]. The blockchain could link many computers via nodes, and requires no transactions to build a new block that helps send safe information from one person to another. The client may Systems 2023, 11, 38. https://doi.org/10.3390/systems11010038 https://www.mdpi.com/journal/systems