Table 10.

Solutions are used for difficulties in the mentioned RQ 6.1

Solutions to addressed the challenges	Frequency
Integrating cloud/decentralized storage to provide off-chain storage for extensive medical data	2
Complies with the GDPR by keeping separate (off-chain data lake) its data from the clinical data (data minimization, right to erasure)	2
Splitting and merging to handle extensive image data to reduce viewing latency	2
Perform parallel processing/ sharding to decrease delay	2
Faster access/querying/analysis with multiple levels of indexing schemes	2
To address the challenges of on-chain data storage by minimizing the data inserted into the chain using reference-based data compression	1
Use an efficient alternative consensus algorithm that is capable of registering provenance for multiple clinical trials	1
Using machine learning technologies to predict the transaction throughput in clinical trials	1
Implementation of the HL7 FHIR API to ensure system interoperability	1
Standards that extend an open protocol that supports efficient standards-based healthcare data exchange	1
Blockchain developers require education on regulatory basics related to healthcare facilities	1
The validation mechanism needed to maintain the scientific integrity of the study	1
The data format must be standardized to promote the interoperability of blockchain solutions for clinical research	1
Smart Contract implementation to improve code consistency across multiple sites	1