Bowing to criticism, the founder and chief executive of the beleaguered medical testing company Theranos said on Monday that the firm would publish data validating the accuracy and reliability of its tests.
At a conference on Monday night sponsored by the Cleveland Clinic, the chief executive, Elizabeth Holmes, suggested that presenting the data would be more effective than trying to rebut articles in the news media that she said unfairly attacked the company.
“Data is a powerful thing because it speaks for itself,” she said.
It is possible that other changes are coming at Theranos as well. A spokeswoman confirmed that David Boies, a well-known lawyer who has been Theranos’s outside legal adviser, will be joining its board of directors. It was not clear whether he would remain an outside lawyer for the company.
Ms. Holmes, 31, who dropped out of Stanford at age 19 to start Theranos and has since become a billionaire, has been featured on the covers of numerous magazines because of her story and her promise to provide rapid and inexpensive medical testing using tiny samples of blood from a finger prick, rather than big tubes of blood drawn from the arm.
But articles this month in The Wall Street Journal and other publications have questioned how well the technology really works.
Mr. Boies, in an interview with The New York Times earlier this month, said the company had been doing a “minority” of its tests using its proprietary technology. The rest were being done on conventional machines, though that was in part because the company had rapidly expanded the range of tests it offered.
The company, which has been secretive about its technology, has not published data on its test in peer-reviewed journals, the established practice in medicine.
Ms. Holmes has said that Theranos, while not against peer review, was concentrating on submitting its data to the Food and Drug Administration for approval, which it said would represent the best validation.
“If someone’s writing anything, they are writing F.D.A. submissions, and that’s our full-time job right now,” she said last week at the Wall Street Journal Digital Live conference in Laguna Beach, Calif..
But in her talk on Monday at the conference in Cleveland, the Medical Innovation Summit, Ms. Holmes said the company would also publish data.
“We were never against that,” she said. “I just always believed that as the F.D.A. decision summaries came out one by one with our data, that actually that would be so much more transparent a model.”
She added, “But that’s O.K., we can publish our data, and so we’re doing that.”
While Ms. Holmes did not provide any details, the Theranos spokeswoman said the company would publish data comparing its technology to reference testing methods and comparing the results of tests using finger prick samples to those using conventional blood draws. She did not say when or where data would be published.
In Cleveland, Ms. Holmes was interviewed on stage by Dr. Delos M. Cosgrove, chief executive of the Cleveland Clinic. The clinic has an agreement with Theranos to help develop the technology, but Dr. Cosgrove said the clinic had “not used the technology on our campus at this point.”
Most of Theranos’s tests are offered through Walgreens drugstores in Arizona. A Walgreens spokesman confirmed part of a report last week in The Wall Street Journal saying the pharmacy chain would hold off on expanding to other states until it had answered questions about Theranos’s technology.
In the interview with Dr. Cosgrove on Monday, Ms. Holmes said that Theranos had a “wonderful relationship” with Walgreens in Arizona, and the companies were talking about where to go next.