There's still no trace of purloined tapes containing backup copies of billing records from University Hospital that stretch back 16 years, but individual patients are beginning to receive letters telling them of the theft and what they can do.

The U. has winnowed the list — once believed to contain 2.2 million people — down to 1.5 million, according to Christopher Nelson, University Hospital spokesman. "We were able to refine the list, eliminating duplicates and those who are deceased. We also identified some bad addresses. Those efforts account for the drop in number."

The first of the 1,425,501 letters, which are being processed and sent from three mailing houses because of the sheer volume, started arriving last week. All the letters should arrive by June 30, he said.

For those whose Social Security numbers were included in the records — 953,208 adults and 93,277 minors — the U. is offering free credit monitoring for a year through an Experian-owned service. Records for another 230,000 adults and 121,422 minors did not include Social Security numbers. There were also 6,863 emancipated minors whose data contained the numbers and 900 whose records did not.

The U. set up a Web page with information, as well as an information phone line. As of Monday night, it had fielded 4,500 phone calls and had 26,000 Web page views.

Nelson said 6,877 patients have signed up for the credit monitoring so far. Experian normally charges $14.95 a month for the service.

Each letter emphasizes that U. Hospitals and Clinics will not contact someone by phone or e-mail regarding the theft and counsels not to release Social Security numbers or financial information to "contacts you have not initiated."

A longtime employee of Perpetual Storage Inc. picked up the backup data on June 1 and was supposed to take it to the company's secure vault in Little Cottonwood Canyon, but instead left it in a gray metal box in a personal car overnight. Someone broke the car window and took the box, sparking a search and an investigation that has involved the Salt Lake County Sheriff's Office, the FBI, the U.S. Postal Service and others.

The U. won't say if the data were encrypted, but it says special equipment or software is needed to access it. It offered a $1,000 reward, no questions asked, for return of the disk, but has had no takers.

"We're continuing to work with law enforcement. And the FBI and Postal Service have said if it were to hit the market, they think they would have an idea about it pretty quick," Nelson said. "The hope is it's sitting in a landfill at this point."

Anyone with information on the tapes can contact the Salt Lake County Sheriff's Office at 743-7000. The U.'s toll-free answer line is 866-581-3599. The Web site for more information is

E-mail: [email protected]