COLUMBUS, Ohio - Better Business Bureau offices across the country have received numerous calls from recipients of a letter from Kroll, an identity theft protection company, offering ID theft protection services in response to Community Health System's (CHS) discovery of a data breach.

Following a data breach affecting at least 4.5 million patients nationwide, people who were referred to or received services from physicians affiliated with CHS in the last five years are being advised to review their credit reports and accounts for possible unauthorized activity.

Tens of thousands of Ohioans may be impacted by the breach, including patients referred to Northside Medical Center in Youngstown, Trumbull Memorial Hospital in Warren, Hillside Rehabilitation Hospital in Howland, and Sharon Regional Health System.

Affected individuals can take advantage of one year of free credit monitoring, which CHS is offering.

“Affected individuals should be receiving a letter." said Ohio Attorney General Mike Dewine. "They should follow the instructions in that letter. Ohioans also can contact my office for information about data breaches and identity theft.”

On August 19, 2014, Community Health Systems Professional Services Corporation, commonly known by its trade names CHS and Community Health Systems, publicly reported a data breach affecting at least 4.5 million patients nationwide.

In July 2014, CHS confirmed its computer network was the target of an external criminal cyber-attack in April and June 2014, by which hackers gained access to patient names, addresses, birth dates, telephone numbers, and social security numbers.

The company has said that to the best of CHS's knowledge at this time, the stolen data did not include patient credit card, medical, or clinical information. CHS has indicated the data breach occurred in physician practices affiliated with the company, not in its hospitals.

CHS recently sent letters to individuals whose information was taken in this cyber-attack informing them about the data breach and how to enroll in free identity theft protection and credit monitoring services.

Affected consumers can expect to receive a notification letter from CHS in the near future. If a consumer actually becomes a victim of identity theft because of the breach, restoration services will be provided free of charge.

Consumers with questions or concerns about this cyber-attack are encouraged to contact 1-855-205-6951 toll-free.

For a full BBB Business Review on Community Health Systems and more information regarding the data breach, click here.

CHS informed BBB that neither they nor Kroll are phoning consumers. BBB cautions consumers to NEVER give personal information to unknown callers.

BBB offers the following advice to consumers on what to do after a data breach:

1. Stay calm. Consumers are not liable for fraudulent charges on stolen accounts.

2. Check the website of the merchant for the latest information. Type the business name directly into your browser. Do NOT click on a link from an email or social media message.

3. If your information was compromised, consider putting an alert or freeze on your credit report with the three major credit reporting agencies. A credit freeze will prevent anyone from accessing your credit report or scores. This means you cannot apply for new credit without lifting the freeze.

4. Keep an eye on your credit report annually by visiting AnnualCreditReport.com. This will assist you with avoiding fraudulent or inaccurate information from being placed on it.

For any additional questions, call BBB at 330.744.3111 for visit bbb.org/youngstown.