The largest drugstore chains in the United States say they are working to better protect patient privacy after an investigative TV report checked city trash bins and found information on hundreds of store customers.

Indianapolis TV station WTHR inspected nearly 300 trash bins and found nearly 2,400 patient records, including pill bottles, customer refill lists and prescription labels.

Most of the bins belonged to Walgreens Co., CVS Corp. or Rite Aid Corp. The inspections were done in more than a dozen cities, ranging from Boston to Louisville, Ky., to Phoenix.

In Canada, pharmacists must abide by security guidelines in the Personal Information Protection and Electronic Documents Act.

Louise Crandall, a spokewoman for the Canadian Pharmacists Association, said the professionals are required to take precautions to protect customers' personal information from unauthorized use and disclosure.

The U.S. television station's investigation began after a grandmother from Bloomington, Ind., was robbed at her front door by a thief, who, according to authorities, found her address in a CVS trash bin. The man posed as a pharmacy employee to try to steal her prescription for the painkiller Oxycontin, the authorities said.

As part of its response, Deerfield, Ill.-based Walgreens Co. said it began instructing staff to lock outdoor trash bins at all times, and was reviewing the way it disposes of patient information.

Privacy a concern

In Woonsocket, R.I., CVS headquarters, 460 patient records were found in CVS trash bins, the station said. Responding to the findings, CVS sent a statement acknowledging it was unacceptable that patient information could be retrieved from the bins.

"Nothing is more central to our health-care operations than maintaining the privacy of health information," the statement said.

The report aired in multiple instalments.

CVS, which operates about 6,200 stores nationwide, said it was now requiring all trash generated in its pharmacies — and not just trash containing patient information — to be placed in special bags to be returned to CVS warehouses.

It said it was also holding in-store training sessions to review proper procedures for handling of pharmacy trash.

Walgreens, the largest U.S. drugstore chain by revenue, said it had e-mailed all its stores to reiterate its policy for handling patient information.

The company also said it was now requiring that patient vials be returned to pharmacy warehouses to be thrown out. Previously, staff had been instructed to either black out patient information or remove labels from vials before putting them in the trash. Outside trash bins are also to be locked at all times, the company said.

Chain works to reinforce rules

Walgreens spokeswoman Carol Hively said Thursday the company was concerned certain employees were not following proper procedures and was trying to reinforce the rules. But she said other TV stations that have conducted similar investigations have not found privacy problems.

Camp Hill, Pa.-based Rite Aid Corp., the country's third-largest drugstore chain, is enforcing current policies and has not made changes, said spokeswoman Jody Cook.

She said company policy calls for pharmacies to shred confidential patient information, such as prescription labels. If the store is not set up to do that, then the information is to be sent back to pharmacy warehouses to be destroyed.

"We have policies in place to protect patient information, so really it was more of a retraining," Cook said.