Secretary of Veterans Affairs Eric Shinseki dodged repeated questions about why he failed to ensure his underlings were not “cooking the books” on patient wait times despite years of warnings during a Senate hearing Thursday.

Senators from both parties pressed Shinseki about repeated warnings going back to 2010 documenting specific tactics being used at Veterans Affairs' medical centers to hide huge backlogs of appointments for medical care.

Since then, a series of reports by the Government Accountability Office, the VA inspector general and Shinseki's own internal medical investigators documented the existence of bogus waiting lists and other paperwork tricks at veterans hospitals nationwide.

Yet Shinseki did not move to end the practice until reports surfaced in Congress a month ago that hospital administrators at the VA hospital in Phoenix were keeping phony appointment books to hide patient backlogs.

As many as 40 patients died there due to delays in care, according to allegations referred to the inspector general for investigation.

When Shinseki was repeatedly asked Thursday by members of the Senate Committee on Veterans' Affairs how he had responded to the previous reports, and whether anyone was fired, he insisted on getting the results of the IG’s investigation and his own internal review of what happened in Phoenix before offering conclusions or taking disciplinary actions.

Several senators voiced frustration, pointing out they that were asking about Shinseki’s response to prior reports, not the ongoing investigation.

Sen. Richard Burr, R-N.C., ranking Republican on the committee, ticked through a list of previous investigations, all of which found records were being falsified at veterans’ health facilities to hide backlogs in care.

“VA's leadership has either failed to connect the dots or failed to address this ongoing crisis, which has resulted in patient harm and even death,” Burr told Shinseki.

“The question we must answer today is, even with all of the information available to the secretary, starting over a year and a half ago, and specific instances of patient harm and death directly related to delays in care, why were the national audits and statements of concern from VA only made this month,” Burr said.

Committee Chairman Sen. Bernie Sanders, I-Vt., also wanted answers about why more has not been done to fix the problem.

“The criticism is that year after year reports have been made talking about these problems and the problems continue to exist,” Sanders said.

“In your judgment, based on what you know about people who were cooking the books, is that in fact a problem within the health care system?” Sanders asked.

“I’m not aware in other than a number of isolated cases where there is evidence of that,” Shinseki responded, adding that the Phoenix investigation and a separate internal audit will document the extent of the problem.

“The IG is going to get to the bottom of that,” Shinseki said.

Shinseki, who was put under oath before beginning his testimony, stuck to that answer as successive committee members asked him about reforms and discipline against agency managers caught falsifying wait times in previous investigations.

Sen. Johnny Isakson, R-Ga., cited an August 2010 internal VA memo that described multiple schemes investigators found being used at health care facilities to manipulate statistics on patient care delays.

That memo — from William Schoenhard, then deputy under secretary for health — called for an immediate end to the practices, including some similar to those allegedly used in Phoenix and other cities that have been exposed recently.

“It has come to my attention that in order to improve scores on assorted access measures, certain facilities have adopted use of inappropriate scheduling practices sometimes referred to as 'gaming strategies,'” the Schoenhard memo said, calling those tactics inappropriate.

Shinseki said he was not familiar with that memo.

Robert Petzel, under secretary for health, was seated next to Shinseki during the hearing and said the agency does try to root out inappropriate scheduling practices.

“It’s absolutely inexcusable,” Petzel said.

Shinseki is under fire from Congress, veterans groups and the media amid widespread reports that delays in care and efforts to cover them up by manipulating paperwork has jeopardized the safety of patients and potentially led to deaths.

The Washington Examiner has reported on many of the tactics used by VA medical centers nationwide to hide large backlogs, some of which have been linked to patient deaths.

In February, the Examiner reported on mass purges of backlogged medical orders in Los Angeles and Dallas to reduce reported backlogs.

Citing GAO reports and testimony, the Examiner also showed earlier this month that more than 1.5 million medical orders were purged.

The allegations about secret waiting lists being kept in Phoenix were first revealed by Rep. Jeff Miller, R-Fla., chairman of the House Committee on Veterans Affairs during a hearing last month.

Miller said there were credible reports that two sets of books were kept at the Phoenix hospital to hide wait times that were longer than allowed in agency policies, and that as many as 40 patients died due to delayed care.

So far investigators have not confirmed any preventable deaths due to delays in care, said Richard Griffin, acting inspector general at VA.

Since Miller's announcement, similar practices have been alleged at VA hospitals in Colorado and Texas.

Miller asked for an inspector general’s investigation, which was later supported by Shinseki.

GAO also is investigating the mass purging of backlogged medical orders to determine whether it resulted in patients being denied care.

Three top administrators at the Phoenix facility were put on administrative leave this month by Shinseki after the move was requested by the IG.

The practices allegedly used in Phoenix were described in a GAO report issued in December 2012.

Several senators asked whether any VA employees had been fired for manipulating patient wait times to meet agency guidelines.

“On this issue, have you ever fired anybody when you find out that they are manipulating the records?” Sen. Mark Begich, D-Alaska, asked at one point.

“I would say manipulation of the data, the truth, is serious,” Shinseki responded.

“Would you fire them?” Begich pressed.

“I will do everything I can,” Shinseki said.

“That’s not the question,” Begich continued.

“There is a process here, senator,” Shinseki replied, again apparently referring to the ongoing investigation rather than past findings of wrongdoing. “Let me not get out ahead of it.”

Begich also asked whether anyone was fired after being identified in the 2010 investigation by Schoenhard.

Shinseki said he doesn’t know and hasn’t seen the memo.

“I would say if there was any manipulation that identified some individuals, I would expect to see their names on that list" of fired employees, Shinseki said.

He was referring to a list of approximately 3,000 VA employees forced out of the agency last year for any reason.

Reports of patients dying because of delays in care, manipulation of records and phony wait lists drew bipartisan outrage from members of the committee.

Sen. Richard Blumenthal, D-Ct., said falsifying records is a crime and the allegations warrant a criminal investigation by the FBI.

Shinseki said he would rely on the inspector general to make that decision.

Griffin, the acting IG, said he has criminal investigators working on the Phoenix case, and is cooperating with federal prosecutors to determine if criminal charges should be filed.

Sen. Mazie Hirono, D-Hawaii, questioned whether performance bonuses paid to top administrators created an incentive to cook the books, especially since there seems to be a lack of accountability at the VA.

Sen. Patty Murray, D-Wash., also suggested bonuses create a perverse incentive for wrongdoing.

“Clearly this problem has gone on far too long,” Murray said, noting there have been reports going back more than 10 years warning of falsification of patient wait times.

“The lack of transparency and the lack of accountability is inexcusable and cannot continue. The practices of intimidation and cover-up have to change. Giving bonuses to hospital directors for running a system that places priority on gaming the system and keeping their numbers rather than providing care to veterans has to come to an end,” Murray said.