Students in high-risk groups are more likely to miss school — and according to a new study, Idaho’s absentee numbers are more or less in line with the national averages.

Not surprisingly, students with high absentee rates are more likely to struggle on standardized tests. However, Idaho’s achievement gaps were less pronounced than average.

These are some key findings from “Mapping the Early Attendance Gap,” a study released Monday by a pair of nonprofit groups, Attendance Works and the Healthy Schools Campaign.

The study attempted to pinpoint absentee rates by looking at a variety of high-risk groups, such as black and Hispanic students, students with disabilities and students from low-income households.

“It’s not enough to say we have an absenteeism problem,” said report co-author Hedy Chang, director of Attendance Works. “We need to know who is missing too much school, when and where absences are mostly likely to occur and why students are chronically absent.”

A few thumbnails on the Idaho numbers, collected between 2011 and 2013 (warning: lots of numbers ahead):

• Overall, 20 percent of fourth-graders and 21 percent of eighth-graders were considered chronically absent — meaning they missed three days of school in the span of a month. The national averages were 20 and 22 percent, respectively.
• Among Hispanic students, Idaho’s absentee rate was 22 percent in fourth grade and 23 percent in eighth grade. Both were slightly above the national averages of 21 and 22 percent.
• Among students eligible for free or reduced-priced lunch, the Idaho absentee rates were 22 percent in fourth grade and 24 percent in eighth grade. The national numbers were 23 and 24 percent, respectively.
• Students with disabilities had absentee rates that came in slightly below the national numbers. In Idaho, those absentee rates were 24 percent in fourth grade and 27 percent in eighth grade, compared with national averages of 25 and 28 percent.

Again, a lot of numbers here. The bottom line: Idaho’s absentee rates don’t differ that much from the national averages.

Now, let’s apply the numbers to an achievement question. How do these absentee numbers affect student performance, in Idaho and beyond?

To address this question, the study’s authors looked at fourth- and eighth-grade scores on the National Assessment of Educational Progress.

In Idaho, fourth-graders with high absentee rates scored 11 points lower on the NAEP; eighth-graders averaged 13 points lower. Nationally, the dropoff was 12 and 18 points, respectively.

The achievement gaps were actually a little narrower for students who qualified for free and reduced lunch — an interesting trend that occurred in Idaho and nationally. In Idaho, chronically absent fourth-graders from low-income households scored 10 points lower on the NAEP; eighth-graders scored 12 points lower. Nationally, those gaps were 9 and 15 points.

The bottom line here: absenteeism leads to lower test scores, but Idaho’s achievement gaps aren’t quite as daunting, compared to the national numbers.