Minnesota health regulators failed to meet federally mandated deadlines to investigate the most serious nursing home complaints in six out of every 10 cases — even after pressure from the Legislature and elder-care advocates prompted state health officials to conduct a massive overhaul of its complaint investigation unit.

Data released Tuesday by a federal watchdog agency shows the Minnesota Department of Health still missed deadlines for 150 cases in 2018 that alleged that patients were either at immediate risk for further harm or had been seriously harmed.

The federal government, which helps pay for nursing home care through the Medicaid insurance program for the poor, requires states to respond rapidly to the most egregious complaints in an effort to protect residents from continued abuse, neglect or maltreatment.

"The people of Minnesota expect that their loved ones are going to be safe in these facilities, and it doesn't sound like they are really very safe yet," said Sen. Jim Abeler, R-Anoka.

Health department officials said the lapsed deadlines reflect a period when the agency was struggling to repair its complaint investigation system.

"The progress that we've made since this data snapshot is very real," said Health Commissioner Jan Malcolm. "But we have always acknowledged that we have a way to go to hit our compliance targets."

Last year, the agency managed to eliminate a backlog of more than 3,000 complaints about nursing homes, home care and hospitals. It also cut the average time to finish cases by two-thirds, improvements made through a new computer system and more staff.

An audit by the Office of the Minnesota Legislative Auditor released in March 2018 found that the Office of Health Facility Complaints (OHFC), which investigates maltreatment reports, was poorly managed and failed to meet investigative deadlines for a large share of its cases. A Star Tribune series in late 2017 revealed long delays in state maltreatment investigations, including lost or destroyed files.

Under federal regulations, states must respond to what are known as "immediate jeopardy" complaints — those in which residents are at a continued risk of harm — within two days. In 2018, the state missed that deadline in 37 of 63 cases for a failure rate of 59%. By comparison, just 13% of similar cases nationwide were not launched on time.

Minnesota's on-time record has gotten worse. In 2016, by comparison, state regulators missed the deadline 35% of the time, according to data released by the Office of Inspector General for the U.S. Department of Health and Human Services.

"I would like to think that they are on the upswing and improving," said Jean Peters, president of Elder Voice Family Advocates. "That they did fail to investigate in a timely manner is unacceptable."

Another category of complaints, known as "high priority" because a resident had been significantly harmed, requires states to start investigating within 10 days. Minnesota missed that deadline 61% of the time in 2018, with 117 of 191 complaints taking longer to start. In 2016, 64% were not investigated promptly.

"They have told us that all is well and they are on track," said Abeler. "It sounds like all is not well and is not on track."

The number of nursing home complaints soared in 2018 to 1,224, a threefold increase from 444 in 2016. About 20% of the 2018 complaints were considered either immediate jeopardy or high priority.

It is unclear if the number of complaints has increased because regulators are keeping better track of them. The Star Tribune reported in 2017 that OHFC workers dumped dozens of maltreatment complaints into recycling bins without investigating them, while unread complaint forms piled up into stacks 2 feet high and went unexamined for months.

At the same time, families were asking the agency to investigate instances of harmful care, beatings, sexual assaults and theft. Many of these complaints were never addressed, and if they were, families often were not informed of the investigative outcomes.

Malcolm said fixing the problems at the OHFC was a high priority when she was appointed in early 2018. The agency secured new funding to increase staffing and has improved methods to identify and address high priority cases. The agency could not provide current data about deadline completion Tuesday.

The Centers for Medicare and Medicaid Services (CMS), which runs the Medicaid program, has been working the Health Department to improve its performance.

"There were some concerns from CMS and now we've been working with them on a number of things to make sure we can meet the standards," said Marie Dotseth, an assistant commissioner at the department.

Staff writer Chris Serres contributed to this report.