Some students are taking 'sick days' to a whole new level.

According to USA Today, new research estimates that 10%-15% of students nationwide are 'chronically absent'.  That means as many as 7.5 million students miss a month of school each year.  That many missed days raises the likelihood that the student will fail academically and drop out of school.

The research was done by education researcher Robert Balfanz of Johns Hopkins University.

He told USA Today one of the biggest dilemmas is that most states don't even measure how many kids miss more than a few days of school over a year.  Only six states track chronic absenteeism: Georgia, Maryland, Nebraska, Oregon, Rhode Island and Florida.

Balfanz said students who miss a lot of school in one year will be more likely to miss several days in the following years.

USA Today contributed to this report