Data localisation is proving to be one of the biggest challenges facing trusts moving over to new picture archiving and communication systems as their national contracts come to an end.

Alasdair Thompson, the PACS programme head at the Health and Social Care Information Centre, which has taken over PACS work from NHS Connecting for Health, outlined the scale of the challenge at UKRC in Liverpool.

He said that 4 petabytes (4m gigabytes) of data had already been transferred from local service providers to the local data stores of trusts. The ongoing move was “the biggest data migration exercise in the world,” he said.

Some individual trusts are facing a significant data migration exercise in their own right, Thompson added.

“There are trusts out there with 80 terabytes of data held within the data stores, and depending on the solution you’ve got, you can be looking at moving two to three terabytes a month. That’s would take 40 months.”

Fortunately, he said, only a small number of trusts are in that position, and there are solutions for dealing with the problem.

He said one approach is migrating two years’ worth of data, and then continuing to use the old data stores with the new PACS system until the rest of the data is migrated.

Trusts have different options for migrating data, depending on where they are located, Thompson added.

The cheapest and simplest option for both London trusts and those in the North East and East Midlands regions is to move data using DICOM Query/Retrieve. This is suitable for moving a maximum of 10 terabytes of data, and the cost is included in the existing contract.

Trusts in the NEEM region can also opt for the bespoke movement of data, using a portable storage device to physically move the data from the data centre to the trust.

Alternatively, they can keep the data in the Accenture vendor neutral archive, as Accenture is remaining in the PACS programme, and transfer it at a later date.

London trusts are also being offered an enhanced migration strategy, which will involve a file copy of the database files across the N3 network.

“The key lesson here is to separate your data migration activity form your PACS procurement,” said Thompson.

“If you wait until you’ve selected your PACS provider to start your data migration, particularly if you go through OJEU, which can take a year, you’re not migrating your data when you could be.”

In the next three weeks, 86 trusts will leave national PACS contracts negotiated by NPfIT. That includes all 78 trusts in the North West, West Midlands and Southern clusters, where CSC was the local service provider.

It also includes six trusts from the East of England, East Midlands, Yorkshire and the Humber and the North East clusters, who chose not to accept the offer of an extension to their Accenture contract, and two London trusts who opted to leave the contracts early.

Thompson said that trusts had learnt a lot during the PACS refresh, and that the HSCIC website would be used to share best practice with trusts yet to undergo the procurement process.