SEATTLE — Washington’s beleaguered state mental hospital hasn’t been accredited for more than three months, but it failed to mention that fact to many staff or prospective employees — something officials described as an unintentional oversight.

As first reported Monday by KOMO-TV (http://goo.gl/FCC5mb ), Western State Hospital in Lakewood continued to claim on web postings, fact sheets and job listings that it was fully accredited by The Joint Commission, an Illinois-based organization that evaluates medical providers. In reality, it gave up the accreditation in late May rather than undergo an impending survey by the organization, and in the meantime said it’s working to come into compliance with federal standards under a reform agreement announced in June.

“We thought this information had been shared via the electronic bulletin board, but it wasn’t found after doing a preliminary search of the site,” the Department of Social and Health Services, which runs the hospital, told staff in a statement dated Sunday.

The department on Monday began scrubbing its websites and job postings of references to the accreditation.

Western State has been plagued by assaults on staff as well as hiring and quality-of-care issues. In April, two dangerous men, including one charged with torturing a woman to death, escaped out a window.

The decision to forego accreditation came just before the hospital entered a reform agreement with federal regulators in June to fix safety problems that threatened millions of dollars in federal funding. Western State was due for a survey by The Joint Commission in June, but requested a delay.

The organization refused, and DSHS — following discussions with the governor’s office, the attorney general’s office and the federal Centers for Medicare and Medicaid Services — decided it was unlikely to succeed in maintaining accreditation with The Joint Commission until it comes into compliance with federal standards, Carla Reyes, assistant secretary for the DSHS Behavioral Health Administration, said in a written statement Monday.

“Given this reality, it did not make sense to go through another external survey since we are now working directly with CMS,” she said. “We don’t believe that lack of accreditation will jeopardize the care, safety and security our patients. However, they will be impacted if we continue to not meet the CMS conditions.”

She said that according to Western State Chief Executive Cheryl Strange, “there were discussions about the change during supervisors meetings and leadership team meetings,” but “the website and hiring information was not updated with this information. This was an unintentional oversight which the hospital has moved immediately to correct.”

Paul Vilja, a nursing supervisor at Western State, said he filed a whistleblower complaint over the weekend after learning that the hospital had not disclosed to staff or prospective employees that it no longer had accreditation. Vilja said he first heard the news late last week, after a co-worker attended a “high-level” meeting and was stunned to hear of it.

“No staff were informed, no union was informed,” he said. “It was done in silence, essentially.”

Vilja said the news has serious implications for hiring at Western State.

“People will not apply to work here as soon as they find that out,” he said. “If you go work for a facility or agency that’s not accredited, there’s a higher probability you may be asked to take an action that would endanger a patient. There’s a higher likelihood you could lose your license.”

The state’s other mental hospital, Eastern State, near Spokane, remains accredited.