One of the largest medical and research organizations in Canada is conducting an internal review of five years’ worth of all of their patients’ digital records after multiple mix-ups were discovered, CTV News has learned.

The University Health Network, which oversees a number of hospitals including, Toronto General, Toronto Western, Princess Margaret, Toronto Rehab and the Michener Institute, confirmed to CTV Toronto that they’re investigating four cases where a patient’s medical information was found in another patient’s online file.

"From all investigated data to date, there have only been 4 cases where misfiled information was identifiable and therefore there are only 4 privacy breaches confirmed to date, but of course investigation is on-going,” Gillian Howard, the UHN’s vice-president of public affairs, said in a statement on Thursday.

The problem was first uncovered by a patient who checked his online account with the organizations’s myUHN Patient Portal network and noticed the results of a medical test he had never taken included in his records. As it turned out, another patient’s information had been electronically deposited into his profile.

In all four of the cases currently under investigation by the UHN, a patient’s information was misfiled and placed into another patient’s electronic records. The health organization has attributed the problem to an “electronic glitch” within their computer network.

The glitch was deemed serious enough to prompt the UHN to temporarily shut down its digital system, effectively cutting it off from the rest of Ontario’s electronic health network.

The organization said it will keep the system closed for another 10 days or so as they finish going through their logs of patient records to ensure there aren’t any other mistakes.

The four patients whose information was placed in the wrong files have been notified, the UHN said.

With a report from CTV Toronto’s Paul Bliss