Watson Health is making another bold move in health care big data — it has just announced plans to acquire Truven Health Analytics, a leading provider of cloud-based health care data, analytics and insights for $2.6 billion.

The Truven purchase showed “we’re serious, and spending serious money to move fast in a whole new industry for IBM,” John E. Kelly, IBM senior vice president, told the New York Times.

The Truven deal will add over 8,500 clients, including U.S. federal and state government agencies, employers, health plans, hospitals, clinicians and life sciences companies, to the Watson Health portfolio.

"Together, we're well positioned to scale globally and to build first-in-class offerings designed to help our clients apply cognitive insights in a value-based care environment," Deborah DiSanzo, general manager for IBM Watson Health, said in a statement.

Truven Health Analytics is owned by Veritas Capital, which bought it from Thomson Reuters for $1.25 billion in 2012, according to Reuters.

The deal is IBM's fourth major health data-related acquisition since launching the Watson Health unit in April 2015. When it closes, the company will have invested more than $4 billion in its cognitive health care capabilities, which aim to improve outcomes, control costs, and advance value-based care solutions.

Truven will give IBM “200 million lives which we can combine with 100 million patient records. We can combine our data sets together, including one of the largest democratized health records with electronic health records from Phytel, Truven, claims data, imaging data, genetics, medical health data and from all of that we can run analysis,” DiSanzo told Fortune in an interview.

The Truven acquisition, Kelly noted, fits nicely into IBM's Watson Health earlier acquisitions, including Explorys and Phytel, which gave it electronic medical records data, and the billion-dollar buy of Merge Healthcare, a medical imaging software company, which brought health image data management expertise to the table.

Truven, Kelly told the Times, adds payment information to the growing data set, including coding for disease, diagnosis, drugs prescribed, and other data that permit outcome tracking.

“It’s a very key cog to give us one of the most complete data sets on patients and health care in the world,” noted Kelly.

Data and insights from Truven inform benefit decisions for one in three Americans, according to IBM. This sort of analysis is of major importance as the U.S. health system shifts to outcome-based payment and away from fee-for-service.

“Data is important,” health care IT industry veteran Todd Cozzens, managing director of Leerink Capital Partners, told Crain's business. According to Cozzens, the lynchpin of matching patients' outcomes to disease, treatments and co-morbidities is the the matching of claims and clinical data. These data are available through just a few firms: Truven, Health Catalyst, Cerner or Epic.

“It's a race for who can come up with the most valuable data. That is the future of health care – what are the most effective drugs, care paths and what combination of therapies work best,” said Cozzens.

The deal will add over 5,000 employees to IBM's roster. "The Truven Health Analytics team is eager to combine our capabilities and expertise with the Watson Health portfolio," Mike Boswood, president and CEO, Truven Health Analytics, said in a statement, adding that the deal should "help catapult the industry forward to transform health care and to save and improve lives."

The deal is slated to close later in 2016, once it satisfies closing conditions and passes regulatory reviews.