Story highlights The CBO previously said the original health care bill would leave 24 million more without coverage

The House is voting Thursday on the Republican bill to repeal and replace Obamacare

(CNN) The White House Thursday defended the decision to vote on the health care bill without waiting for a new analysis from the nonpartisan Congressional Budget Office.

The bill contains too many unknowns for the office to successfully predict its effects, Deputy Press Secretary Sarah Sanders said.

"I think even if they were to score it, it is impossible to score a lot of the things that would go into this, because it has so many different factors that you simply can't predict: what governors may do in their states, specific conditions that patients may have," she said. "So even if it was to be scored, I think it would be impossible to predict how that might actually affect and impact."

As originally introduced in March, the GOP health care replacement bill would leave 24 million fewer people insured by 2026 than under Obamacare, CBO said. The legislation has been altered since then, but the CBO will not release a new report before the House vote on the bill Thursday.

A Texas Republican who practiced medicine for 25 years is confident the bill won't result in millions losing coverage due to less federal funding of Medicaid.

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