# Centralized vs. Decentralized Cloud Computing in Healthcare
###### Abstract  
Healthcare is one of the industries that seeks to deliver medical services to patients on time. One of the issues it currently grapples with is real-time patient data exchange between various healthcare organizations. This challenge was solved by both centralized and decentralized cloud computing architecture solutions. In this paper, we review the current state of these two cloud computing architectures in the health sector with regard to the effect on the efficiency of Health Information Exchange (HIE) systems. Our study seeks to determine the relevance of these cloud computing approaches in assisting healthcare facilities in the decision-making process to adopt HIE systems. This paper considers the system performance, patient data privacy, and cost and identifies research directions in each of the architectures. This study shows that there are some benefits in both cloud architectures, but there are also some drawbacks. The prominent characteristic of centralized cloud computing is that all data and information are stored together at one location, known as a single data center. This offers many services, such as integration, effectiveness, simplicity, and rapid information access. However, it entails providing data privacy and confidentiality aspects because it will face the hazard of a single point of failure. On the other hand, decentralized cloud computing is built to safeguard data privacy and security whereby data are distributed to several nodes as a way of forming mini-data centers. This increases the system's ability to cope with a node failure. Thus, continuity and less latency are achieved. Nevertheless, it poses integration issues because managing data from several sites could be a problem, and the costs of operating several data centers are higher and complex. This paper also pays attention to the differences in aspects like efficiency, capacity, and cost. This paper assists healthcare organizations in determining the most suitable cloud architecture strategy for deploying secure and effective HIE systems. cloud computing; health information exchange; centralized cloud computing; decentralized cloud computing 202  
faced with paper records include lost data; poor record keeping, since some writings may be hard to read; data being accessible by a single user; and the physical burden of paper [3; 4]. To solve the problem, electronic medical records (EMRs) [5] have gradually replaced paper records for recording patients' information to allow hospitals to store patients records electronically where necessary. They have several benefits. They present documents with a standard format with easy access and retrieval. This not only results in the efficient and accurate documentation of patient information but also reduces hospital expenses. In addition, it enhances patient safety by documenting important information that would include drug-drug interactions and allergic reactions to ensure that all medical procedures adhere to the recommended guidelines to avoid adverse effects [6; 7]. Nevertheless, one of the demerits that comes with EMRs is that the patient care offered through the EMR system is limited to the specific healthcare facility, with no connection to any other facility [8]. With the improvement of the healthcare systems, there was a demand for integrated and community-wide health information, leading to the definition of EHRs. They are advanced versions of EMRs that provide not only the consolidated record of the patient but also the record of health information from a number of healthcare organizations and comprise data received from various sources, including medical records, laboratory results, reports on radiology, and data on pharmacy. They are supposed to be seamless in order to support HIE and the exchange of patient information within and across the participating healthcare centers [9].