Providence officials said there have been no reports that any of the stolen information has been used improperly since the incident.

Providence is notifying affected patients by mail about the theft. The information on the disks and tapes included names, addresses, dates of birth, physicians' names, insurance data, diagnoses, prescriptions and some lab results. For approximately 250,000 of the patients, Social Security numbers were on the records, according to the health system. Some of the records also included patient financial information.

Rick Cagen, CEO of Providence's Portland service area, said new backup procedures are being implemented using more traditional IT means, including secure sites in remote locations for safety and redundancy. "We do have alternate practices now," Cagen said.

The four-week delay in publicly announcing the theft was needed so Providence officials could recreate the stolen data and identify the patients who needed to be contacted, he said. The delay was also caused in part by the large number of records that had to be processed, he said.

"We realize this is a major inconvenience and cause for real concern, and we deeply apologize to everyone affected by this incident," Cagen said. "Even though we have no indication that the thief has accessed the data, we are doing all we can to help our patients and employees protect their information."