Atrium, which provides healthcare and wellness programs throughout the Southeast region in the United States, said a review revealed an unauthorized access to AccuDoc's databases between Sept. 22 and Sept. 29.
An Atrium spokesman said investigations indicate that data was accessed but not downloaded in the incident.
Personal clinical and medical records were not involved, nor was financial account information, such as bank account numbers or credit card or debit card information, the company said.
AccuDoc informed Atrium Health about the breach on Oct. 1.