SAUK CITY, Wis. -

Unity Health Insurance said Thursday morning that a missing hard drive could compromise patient information for more than 40,000 members. 

The health insurance group said the portable computer hard drive was reported missing by the University of Wisconsin-Madison School of Pharmacy on Dec. 12. Unity identified 41,437 members who may have been affected by the breach and sent letters Wednesday to notify them.

"Obviously this is a concern for us. We did not live up to our members' expectations, our expectation or the federal government's expectation, so this is a concern for us, and we take these matters seriously," Unity Health CEO Terry Bolz said.

Unity said the information on the hard drive included the Unity member number, date of birth, city of residence, name of prescription drug, dates of service, if any. Some of the information on the drive was protected health information relating to certain prescription drugs, Unity spokeswoman Jennifer Woomer-Dinehart said. 

According to the group, the data on the drive did not contain the name, street address, Social Security number, credit card, banking or financial information of any Unity member.

"We have no reason to believe the hard drive was stolen to gain access to member information or that this information has been accessed or misused in any way," Dinehart said. 

Bolz said there's no indication that any of the information is being used in a malicious way, but they are offering a year of identity theft prevention services to the members whose information was on the drive. Members with questions regarding can contact ID Experts at 888-738-3786.

"We apologize for the concerns and the uncertainty that this creates. We will work hard to provide thorough ID experts and whatever we can do to reassure our members that we're helping protect their identity and so again, we apologize," Bolz said.

Unity and the UW School of Pharmacy said they are reviewing policies and re-educating employees on measures to protect member information. 

Unity Health Insurance is headquartered in Sauk City.