Shoddy healthcare practices at Cooley Dickinson Hospital in Northampton, Massachusetts, led to the preventable deaths of two babies and a pregnant woman between 2013 and 2014. That’s according to federal regulators who threatened to cut the hospital’s federal funding over its poor performance. Yet most of the hospital’s patients had no idea of the dangerous state of affairs at the time—the hospital maintained its accreditation throughout the three tragedies, and, according to an investigation by The Wall Street Journal, it was even called a top performer by its accreditor, the Joint Commission.

The situation at Cooley Dickinson is not unique; patients nationwide are being potentially misled about the quality of their care. According to data collected by the Journal, hundreds of hospitals with federal safety violations continue to boast accreditation and a “Gold Seal of Approval” from the Joint Commission, a nonprofit that the government relies on to accredit almost 80 percent of US hospitals.

Hospitals can use state inspections to prove they’re in compliance with federal safety standards and eligible to receive money from federal health programs. But many rely on accreditations and programs from private organizations such as the Joint Commission, which is the largest of the private accreditors. Some states have even allowed private accreditors to take over much of their role inspecting hospitals.

But the Joint Commission appears reluctant to downgrade a hospital’s status. In fact, the Joint Commission revoked the accreditation of less than one percent of the hospitals that ran into trouble with federal regulators in 2014, the Journal found. Like Cooley Dickinson, at least 30 accredited hospitals’ violations were so bad, federal regulators reported that they caused or were likely to cause serious injury or death to patients.

The alarming stats come out of a database the Journal put together for its investigation. The database combines inspection-report results from federal regulators—the Centers for Medicare and Medicaid Services (CMS)—plus state inspection reports. With that information, the Journal overlaid the accreditation status by the Joint Commission.

That data showed that about 350 hospitals had CMS violations in 2014 while also being accredited by the Joint Commission. Sixty percent of those also had CMS violations in the previous three years. And more than a third went on to have more violations in late 2014, 2015, and 2016.

The Journal also pointed out potential conflicts of interest with the accreditor. Twenty of the Joint Commission’s 32 board members were executives of or affiliated with health systems the Joint Commission accredits. Also, the Joint Commission accredits and inspects facilities for fees while also offering subsidiary resources that hospitals can hire to help improve care and get accreditation.

On its website, the Joint Commission boasts that:

Earning accreditation or certification from The Joint Commission signifies many things, with none larger than a devotion to patient safety. By earning our Gold Seal, you’re telling your staff, competitors, community, and each and every patient that comes through your doors that you have placed an emphasis on quality of care.

But the Journal’s data “shows accreditation is basically meaningless—it doesn’t mean a hospital is safe,” according to Dr. Ashish Jha, a health-policy researcher at Harvard University. “It’s clearly a failed system and time for a change.”

The Joint Commission declined Ars' request for comment.