A portable hard drive containing health information for up to 41,437 people with Unity health insurance has been missing for seven weeks, prompting the company to offer identity theft protection.

The hard drive did not contain the name, street address, Social Security number, credit card, banking or financial information of any Unity member, the company said in announcing the incident Thursday.

Information on the hard drive was limited to the Unity member number, date of birth, city of residence, name of drug, and date of service, if any, the company said.

“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,” Unity said in a statement.

Like this story? If so, subscribe to Government Technology's daily newsletter.

Unity learned Dec. 12 that the hard drive was missing from the UW-Madison School of Pharmacy, which had it as part of a benefits program evaluation.

“The disappearance was reported to the police and immediately investigated,” the statement said.

Unity and the pharmacy school are instituting an “information and re-education initiative” to ensure member information is protected.

Letters to members potentially affected were mailed Wednesday. They will be able to enroll in a one-year identity theft recovery program.

©2014 The Wisconsin State Journal (Madison, Wis.)