More than 6 million kids are chronically absent. What gets them back in class?

In schools across the country, teachers have long fretted about the challenges of reaching students who don't come to class. Education researchers echo those concerns, saying that missing 10 percent of the school year – just two days a month – is a strong predictor of the likelihood of dropping out of school.

This week, the Education Department provided the first comprehensive look at the issue through its 2013-14 Civil Rights Data Collection, an annual report that examines a variety of issues facing students in schools across the country, including school discipline.

Its results are striking: More than 6.5 million students were "chronically absent" during the 2013-14 school year, meaning they missed 15 days or more of school per year. That's the attendance record for 1 in 8 students, according to the department's survey of 95,000 public schools nationwide.

"Even the best teachers can't be successful with students who aren't in class," Education Secretary John B. King Jr. said on Tuesday.

The data on chronic absences has renewed discussions of how to tackle the myriad reasons students miss school: illnesses, family responsibilities, a feeling that a school is unsafe or they don't see its value, for example.

The Education Department, which is gathering a variety of educators for a related conference that began Thursday, is particularly urging schools to embrace a positive measures, such as mentoring and offering emotional support to encourage students.

"Punitive message and measures," the department says in a "toolkit" for educators and organizations, "are often ineffective and can lead to disproportionate suspensions and expulsions from school and inappropriate referrals of students and families to law enforcement."

In 2007, the Los Angeles Unified School District, the nation's second largest, began tracking students' attendance more closely. It also launched efforts to offer more concrete incentives. In one case, the district partnered with businesses to create a prize drawing for students who held perfect attendance for a month. High school students with a year of perfect attendance competed to win a car.

The district also began placing dedicated counselors in elementary and high schools with poor attendance records to help the schools track attendance and reach out to parents and students. 

"We realize there's no way we can do this by ourselves at the school district," Debra Duardo, the district's director of pupil services, told the nonprofit AttendanceWorks in 2012. "Our resources are very limited. So we're really looking at ways to partner with outside agencies in the community. We own the data and we know who the students are. We can help make the connections to city services."

The Education Department says chronic absence rates are highest in high schools, where nearly 2.6 million students were absent during the 2013-14 school year.

There are also disparities among racial and ethnic groups. Native American and Pacific Islander students were the most likely to be absent, according to the data, with those students more than 50 percent more likely to be chronically absent than white students.

Previously, researchers had often decried the lack of specificity in data on absences, noting that there was no federal requirement to track them. That changed with Congress' approval last fall of the federal Every Student Succeeds Act, which now requires districts to gather absence data and report it.

"The data indicate that chronic absenteeism cuts across gender and geographic location. It is not a male or female, or urban or rural issue. What is still unknown, however, is if the causes of absenteeism vary by gender and region even if the end result is largely the same," Richard Balancz and Vaughn Byrnes, researchers at Johns Hopkins University's Center for Social Organization of Schools, wrote in 2012.

Advocates applauded the release of the data, describing it as call to action. "The good news is chronic absence is a solvable problem," Hedy Chang, the executive director of AttendanceWorks, wrote in a US News column on Wednesday. "Students get to school when educators and community partners join together with families to identify and address the barriers, work to create a more welcoming school environment and help everyone understand the importance of avoiding unnecessary absences."