While many focus attention on student absences and their effect on academic achievement, experts say teacher absences also can have a negative effect. (Getty Images/iStockphoto)

More than 1 in 4 of the nation’s full-time teachers are considered chronically absent from school, according to federal data, missing the equivalent of more than two weeks of classes each academic year in what some districts say has become an educational crisis.

The U.S. Education Department’s Office for Civil Rights estimated this summer that 27 percent of the nation’s teachers are out of school for more than 10 days of regular classes — some missing far more than 10 days — based on self-reported numbers from the nation’s school districts. But some school systems, especially those in poor, rural areas and in some major cities, saw chronic absenteeism among teachers rise above 75 percent in 2014, the last year for which data is available.

In the Alamance-Burlington School System, located between Greensboro and Chapel Hill, N.C., 80 percent of its 1,500 teachers missed more than 10 days of school in the 2013-2014 school year. Cleveland reported that about 84 percent of its 2,700 teachers had excessive absences. Nevada’s Clark County School District, which includes Las Vegas, reported that more than half of its 17,000 teachers were chronically absent — missing a total of at least 85,000 work days, or the equivalent number of hours that nearly 500 teachers would work during an entire 180-day school year.

Although much attention focuses on the 6 million students who miss more than 15 days of school each year, making them much more likely to see low achievement and increasing the chances of not graduating, , teacher absences could be having a similarly negative effect on scholastic success. Superintendents and education policymakers say students need consistency in the classroom and high-quality instruction, noting that a parade of substitutes can seriously set back academic progress.

In this April 18, 2014 photo, students listen to a substitute teacher during a world studies class in Olympia, Wash. (Ted S. Warren/AP)

“Most teachers are there all the time, as they should be, because they want to be in the classroom,” said Nithya Joseph, director for state policy at the National Council on Teacher Quality. But those who aren’t there all the time could be hurting their students.

“When the teacher of record is not in the classroom, it has an impact on student achievement,” Joseph said.

The National Bureau of Economic Research has found that when teachers are absent for at least 10 days, there is a significant decrease in student outcomes. The decrease, according to one study, is equivalent to the difference between having a new teacher and one with two or three years of experience.

School district administrators do not know what exactly is causing excessive teacher absenteeism. Some point to teachers taking sick leave, maternity leave and personal days to which they are entitled, and others attribute part of the problem to school climate. When teachers don’t feel motivated to go to school and teach, some of them just don’t show up.

That’s what happened with Sean McGrath, a former social studies teacher in the District’s Stuart-Hobson Middle School. During his first seven years as a teacher, McGrath said he missed a total of 17 days.

McGrath then accumulated seven absences since the beginning of September, although he said he was only sick for one of those days. He quit his job last month, saying he felt he did not have his principal’s support and that he thought the school didn’t have enough support staff to control behavior in the building.

“I would wake up in a panic and feeling like there was a pit in my stomach,” McGrath said. “It was a feeling of dread and despair.”

Three other teachers at Hobson echoed McGrath’s sentiments, saying in interviews that they feel stressed out about going to school; one other teacher told The Washington Post that she has quit her job because of the school environment.

Stuart-Hobson, on Capitol Hill, reported that 58 percent of its teachers missed more than 10 school days in the 2014 school year, one of the highest rates in D.C. Public Schools.

Michelle Lerner, a D.C. Public Schools spokeswoman, said chronic teacher absenteeism in the school system is in line with the national average, at about 30 percent. Lerner said 80 percent of the school system’s teachers report that they are in a good place to teach, a number that has increased since 2014. She said Hobson’s principal was not available to speak about her school’s climate, and the principal did not respond to requests for comment.

In the Washington area, Fairfax County schools are in line with the national average while Arlington and Prince William County schools were both slightly above the national average. Montgomery County reported that just 14 percent of its teachers are chronically absent, about half the average.

The estimates from the Education Department indicated that 58 school districts with more than 1,000 full-time teachers had chronic absentee rates above 50 percent.

Although the federal absentee data was self-reported, several school districts told The Post that their numbers appeared to be incorrect, and sometimes wildly so. Although school districts were not supposed to include professional development days in their tallies, some did. And some of the data was erroneous: The Onslow County, N.C., school district, for example, was shown to have 99 percent of its teachers chronically absent but said its number is actually 19 percent. Many school districts confirmed that their number of teachers chronically absent was still far higher than the national average.

School officials with the Alamance-Burlington school district in North Carolina said they are alarmed by high teacher absenteeism, which was approximately 80 percent in 2014. The district began conducting regular surveys about teacher morale and increased teacher pay slightly.

The efforts have yielded results, bringing the number of teachers who missed more than 10 days down to about 50 percent last school year. But Superintendent Bill Harrison still considers that rate unfortunate.

“We still have too many days that our students don’t have that quality teacher in front of them,” Harrison said.

North Carolina ranks above the national average in teacher absences, and school district leaders there say state laws that grant personal leave and sick days are a contributor. Others say the state’s large military population has an impact. In Onslow County, a district that surrounds the Marine Corps’ Camp Lejeune, school officials said their teachers are mostly young military wives, many of whom take maternity leave or take days off when spouses return from deployments.

Randi Weingarten, president of the American Federation of Teachers, said the federal data doesn’t paint a fair, complete or accurate picture because it only reports when teachers are out of their classrooms, not why they are out, such as for illnesses or family deaths. She also said teachers face unusual workplace stress, and that women, who make up amajority of teachers, are often primary caregivers for their families and are more likely to miss work because of it.

“The data also doesn’t address some other basic conditions faced by teachers — the stress, the need to work beyond the school day and the juggling of work and home that interferes more with their family life than most professions,” Weingarten said. “To better address absenteeism, we need to understand root causes.”

Beth Howard was absent from her classroom for 19 days last school year, leaving her students at Onslow’s Dixon Elementary with a substitute teacher. The art teacher, at the same school for 34 years, said she rarely misses a day of instruction, but last year was different — she had to care for her ailing mother, who died.

Howard prepared detailed lesson plans for her substitute teacher, and she said she worried about her students the entire time. “We wouldn’t have gone into this job if we weren’t dedicated,” Howard said. “Teachers want to be with our kids. If not, we would quit or move on.”

The Guilford County School District, North Carolina’s third-largest, began researching why its students were missing so many days of school. That’s when administrators discovered that teachers also were piling up absences. Federal data show Guilford reported that half of its 4,700 teachers missed more than 10 days of school in 2014.

“It hits you in the face that maybe what you are dealing with is much more basic,” said Nora Carr, the school district’s chief of staff. “No matter what’s going on, if you don’t have a great teacher in the classroom, kids aren't going to learn as much as they would otherwise.”

The district has considered financial incentives for teachers who don’t take a lot of days off. Nevada’s Clark County School District also is exploring financial incentives after it saw more than half of its nearly 18,000 teachers miss more than 10 days of school in 2014.

Mike Barton, the school system’s chief student achievement officer, said replacing thousands of absent teachers is a significant burden, and the replacements are never as good for students.

“I don’t want for one minute for people to think that we are ignoring this,” Barton said. “This is something that we want to make sure improves.”