UnitedHealthcare has teamed up with several large medical systems in a new business venture that will independently test the long-term effectiveness of medical devices.

Combining its members’ resources, the newly formed SharedClarity aims to provide a score card that rates the most widely used heart, neurological and orthopedic devices. The ratings will include such measures as performance, the need for replacement and readmission to hospitals.

The studies will lead to rankings of devices that doctors and other professionals in the SharedClarity network use to make treatment decisions. Test results will also help determine how UnitedHealthcare, the country’s largest health insurer, will cover devices.

The collaboration arose because Minnetonka-based UnitedHealth Group Inc., UnitedHealthcare’s parent company, and other SharedClarity members wanted unbiased ratings of various kinds of devices.

In the past, device manufacturers have been the primary testers of their own products. There was concern among SharedClarity’s members that manufacturer funding and involvement in those studies influenced the results, SharedClarity President Mark West said.

SharedClarity teams UnitedHealthcare with medical service providers Baylor Health Care System of Dallas, Dignity Health of San Francisco and Advocate Health Care in Illinois. The venture is actively recruiting new providers.

Having someone besides manufacturers analyze device effectiveness is a “good idea,” said Eric Campbell, a professor at Harvard Medical School and research director at Massachusetts General Hospital’s Mongan Institute for Health Policy. Campbell said company-funded studies are notorious “for making sure the company is put in the most favorable light.”

Campbell said “the gold standard” for determining device effectiveness would be research done by government-paid scientists with no financial interest in a product’s purchase or use.

That is not happening in the case of SharedClarity because the health systems in the joint venture buy the products and UnitedHealthcare and patients pay for them.

But while hospitals, doctors and insurance companies “are not disinterested,” Campbell said, they are in a more objective position than manufacturers to judge devices.

The Advanced Medical Technology Association (AdvaMed), a trade group representing many of the country’s biggest device makers, expressed concern that SharedClarity’s studies might affect individualized patient care.

“AdvaMed is interested in learning more about SharedClarity’s plans to test the long-term effectiveness of medical devices,” said David Nexon, the trade group’s senior vice president, in a statement. “We believe it is important that ... research not be used to deny patients and physicians their choice of the most appropriate treatment option.”

Physicians in participating hospitals and clinics will study the performance of heart stents, defibrillators, pacemakers, artificial knees and heart valves, among other devices. UnitedHealthcare will share claims data. UnitedHealth Group’s Optum Labs will be a research partner with SharedClarity, as will the Lewin Group, another UnitedHealth subsidiary.

West said individual health care systems in the SharedClarity system have committed to negotiate as a unit to buy their top-rated devices in bulk, garnering a better price for the often-used, costly products.

UnitedHealth will use the study results to negotiate a separate, slightly less favorable price structure for devices that it will offer to all of its customers, West said. Those prices do not require bulk purchases.

The results of the device effectiveness studies will only be available to SharedClarity members initially, West said. But the company may eventually make them available to the public at large.