Optum Labs has brought on four more blue-chip health care organizations in its quest to use big data and a collaborative R&D spirit to improve the health care system.

The organization announced it has added the Harvard Medical School, pharmaceutical giant Merck, the University of Maryland in Baltimore and Minnetonka-based Medica Research Institute to its expanding roster of partners.

Founded by UnitedHealth Group Inc. and the Mayo Clinic, Optum Labs aims to improve medical care and lower the costs of treating patients by exploiting the growing mass of electronic health data.

Its database, the nation's largest, contains insurance claims data (without identifications) on 150 million people over a 20-year period that has been linked with about 30 million patient medical records.

Kristina Bloomquist, executive director of the Medica Research Institute, said her organization researched other national big data initiatives and determined that Cambridge, Mass.-based Optum Labs was "big data done right."

"It's a partner-driven mission; it's not just a rich pool of high-quality data," Bloomquist said. "Partners represent different perspectives, different stakeholders in health care and different research expertise. They are all circling around this rich data pool and working in collegial spirits."

The Medica Research Institute was established in 2010 with $3 million in seed money from parent company, Medica. The institute operates as a separate nonprofit and uses claims data and other publicly available data to conduct national research on health care delivery, community health and consumer behavior.

Optum Labs, which takes its name from UnitedHealth's health IT subsidiary, has attracted more than two dozen organizations from across the health care system. Its partners represent consumer groups, medical device makers, academic health centers and prescription drugmakers.

The size of the database gives researchers an unprecedented view into the cost and quality of medical treatment. More than 20 research studies are underway, Optum Labs officials said.

Other partners with strong Minnesota ties include the University of Minnesota Nursing School and Boston Scientific Corp., which has about 5,000 employees in the state.