## 2 Literature Review
### Collaborative Medical Decision-Making and Blockchain  
Healthcare researchers and policymakers increasingly emphasize SDM for quality treatment [31]. Collaborative medical decision-making has been a common practice in healthcare industries [14; 15; 16; 17; 18; 19; 21; 22; 55]. [PERSON] [56] defines collaborative medical decision-making as:  
* _Medical decision science is a field that encompasses several related pursuits. As a normative endeavor, it proposes standards for ideal decision making. As a descriptive endeavor, it seeks to explain how physicians and patients routinely make decisions, and has identified both barriers to, and facilitators of, effective decision making. As a prescriptive endeavor, it seeks to develop tools that can guide physicians, their patients, and health care policymakers to make good decisions in practice._[56]  
Medical billing, distance patient monitoring, and clinical data exchanging are a few use cases of blockchain technology in the healthcare sector. Medical decision-making, insurance policy sharing, clinical data sharing, and preserving are also managed by blockchain [16; 33; 34; 57; 58; 59; 60]. \begin{table}
\begin{tabular}{p{42.7 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Facts**Type** & **Public Blockchain** & **Private Blockchain** & **Consortium Blockchain** \\ \hline \multirow{3}{*}{Definition} & All participant can read, write, monitor, transact, download and start turning a public node. & Instead of allowing anyone to control and participate in the verification, some specific number of nodes are selected. & Onner of the blockchain has the right technologies. \\  & High & Medium & Low \\ \cline{1-1} Security Privacy Transaction & High & Medium & Medium \\ \cline{1-1} \cline{3-4} \cline{3-  
[PERSON] [16] considered the patient's engagement in healthcare as a key factor to improve the overall medical decision. The study introduced the patient health engagement (PHE) model that includes paternalistic decision-making, informed decision-making, and shared decision-making. This study encourages the active participation of patients in collaborative decision-making. Similar encouragement was also provided by [PERSON] [57] who considered clinical collaboration and payors decisions for upgrading the clinical verdict. The study [57] enrolled 458 patients to find experience (age) with particular diseases as a key aspect in collaborative medical decision-making. At the same time, the study considered the experience and achievement of the decision giving entities (doctor, patient, insurance). So, our study ensures both patients and doctors get an equal participation opportunity in the PoF based collaborative medical decision-making system. A secure medical data sharing platform called'medblock' was proposed by [PERSON] [61]. The study claimed privacy awareness during EMR sharing. The study stored the exact location of data encryption to track EMR access and retrieve. Although the study [61] ensured higher security concept, it failed to provide enough privacy of the patient's identity. Similarly, the study [61] claimed energy efficiency in'medblock' but failed to prove any strong reasons behind their claim. Another study [62] proposed an architecture that stores every possible transaction information, patients identities, medical decisions, insurance records, etc. in a single block. Similarly, [PERSON] [63] introduced Blockchain Applied FASTQ and FASTA Lossless Compression (BAQALC), an efficient blockchain-based platform for DNA sequence transmission. This study also suggests to store the compressed DNA sequence in a block. The main drawback of these studies is that they overlooked the average block size. Oppositely, the proposed system follows a separate storing of personal and non-personal information. The local storing of personal data reduces the overall block size in the blockchain. [PERSON] [64] introduced another medical data handling and decision achieving platform supported by blockchain technology.