Researchers, including one of Indian origin, have developed a novel system based on blockchain technology for ensuring the integrity of clinical trials data.
The system, described in the journal Nature Communications, creates an immutable audit trail that makes it easy to spot any tampering with results—such as making the treatment look more effective or diminishing side effects.
"Everyone is talking about how blockchain is going to revolutionise many of the data challenges in medicine, and here is one use that finally might make sense," said Atul Butte, a professor at the University of California-San Francisco (UCSF) in the US.
"We think it could someday be useful for pharma companies running clinical trials," Butte said.
Blockchain technology utilises an old computer science technique known as hashing, which creates a unique digital signature for each so-called block of data.
The hashes accumulate sequentially, as new data is entered or changed, with each block depending on the last.
The resulting "blockchain" creates an audit trail for regulators that is easy to decipher and validate, even without looking at the actual data.
Daniel Wong, a PhD candidate at UCSF, built the system to operate through a web portal.
Each time new data is entered on a given trial participant, the sender, receiver, timestamp, and file attachment containing the data, along with the hash of the previous block of data pertaining to that patient, is recorded onto a new block, with its own distinct signature.
Unlike the decentralised nature of most blockchain applications, this clinical trial prototype depends on having a regulator with centralised authority, such as the US Food and Drug Administration, to operate the web portal, register all parties, and keep a ledger of the blockchain's hashes.
Data, including adverse events, would be reported to the regulatory agency in real time, which may provide a boost to the safety and efficiency of clinical trials.
While the prototype makes allowances for data entry or other errors to be corrected, new data can only be appended to the existing chain, without erasing what was there before.
"It makes it really obvious when someone's changing something. You can see who put their hands on it, who made it, who changed it, and who received it," Wong said.
After entering the original data, he logged in as the trial sponsor and tried to erase adverse events that had been reported for two patients in their case report forms.
Instead of deleting those reports, however, the system appended his changes to the original data, making it clear who had tried to corrupt the forms, when it was done, and what had been changed.
Wong also tried corrupting the data stored from an earlier point in the trial, when patients were assigned to different treatment arms -- drug or placebo -- to make it look as though they had been given a different medication plan.
However, the blockchain ledger pinpointed exactly what had changed and when.
A prototype system like this reduces risks, but does not completely protect data from tampering.
Even within a system enabled with this type of blockchain technology, the researchers said, it is still possible that those seeing patients at the point of care could enter wrong or incorrect data at the outset.
However, blockchain technology could enable trials to be conducted under challenging conditions, or open doors to data exchanges that are more secure, more efficient, and more transparent for both researchers and the general public.
