# A Blockchain-Applied Personal Health Record Application: Development and User Experience
## 4 Discussion  
In this study, we introduced a blockchain-applied PHR application that enables the exchange of data from hospitals and empowers patients to manage their own data. Through this application, patients can download their data from hospitals to their own application \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Key Theme** & **Category** & **Pros** & **Cons** \\ \hline \multirow{4}{*}{Intention of use} & \multirow{4}{*}{Blockchain} & Blockchain is needed to protect patient data. & Wondering if blockchain is \\  & & Blockchain is needed because it is good in terms of & the only way to protect \\  & & system security. & patients’ information. \\ \cline{2-4}  & \multirow{4}{*}{PHR} & Exchanging patients’ health information is needed. & App provided by the \\  & & Checking my health data anywhere and anytime & hospital can also be used to \\  & & is needed. & check patient health data. \\ \hline \multirow{4}{*}{Acceptance of technology} & \multirow{4}{*}{Blockchain} & \multirow{4}{*}{A basic understanding of blockchain technology.  Users can have sovereign over their own data.} & Does not know about \\  & & & the technology. \\ \cline{1-1}  & & & Users can have sovereign over their own data. & Head of the technology but \\ \cline{1-1}  & & & does not know about \\ \cline{1-1}  & & & the mechanism. \\ \cline{1-1} \cline{2-4}  & \multirow{4}{*}{PHR} & \multirow{4}{*}{No difficulty in using service.} & A manual on how to use the \\ \cline{1-1}  & & & service is needed. \\ \cline{1-1}  & & & Application design needs to \\ \cline{1-1}  & & & be a little more intuitive. \\ \hline \multirow{4}{*}{Health data management and sharing} & \multirow{4}{*}{Blockchain} & Health data could be systemically managed.  Able to independently manage my own health data. & Negative opinion due to not \\ \cline{1-1}  & & & the technology. \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & \multirow{4}{*}{PHR} & Sharing information with medical staff has & Not very interested. \\ \cline{1-1} \cline{2-4}  & & become easy. & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of the pros and cons of blockchain technology and PHR service as reported by users. and can provide reliable information to medical staff anytime and anywhere. Although the application needs more study and validation, it shows that medical information can be stored separately on-chain and off-chain, and thus data security and system stability can be maintained. In addition, we were able to confirm the user experience of the blockchain and PHR through interviews. Unnecessary medical care, such as redundant laboratory testing, procedures, and opioid overuse, is often caused by not sharing patient health records, eventually putting patients' safety at risk [40; 41]. A blockchain-applied PHR is one of the most effective and safe ways to collect patient data. Participants could access their information at any time and from any location using a blockchain-applied PHR, which allows them to self-manage medical data collected through different channels. Additional advantages might include higher healthcare quality through tailored health management services avoiding duplication of medical care, which enables medical information exchange between institutions. Blockchain technology has been used to exchange medical data in previous studies. A study showed the exchange and the management of medical data using a Hyperledger platform, but the privacy was unsecured [26; 27; 28]. Another study used the Ethereum platform to manage EHR data in a cloud setting; however, it was not feasible [25]. Few studies evaluated the user experience of PHR applications using blockchain technology among these studies. This study did not just develop a system but conducted the user experience study with a mixed-method study to listen to the actual voice of users. As a result, authors could easily exchange their medical data through a blockchain-applied PHR application with the confidence of sovereignty on their data.