Washington, Sep 3 : As the new school year has begun, public schools across the US face a common problem -- rising absence rate, which was worsened by the pandemic . Some schools have to get creative to combat chronic absenteeism, as per local news outlets, Xinhua news agency reported. Chronic absenteeism means missing 10 per cent or more of a school year. For students on a typical 180-day school calendar, this totals about one month of missed school. A new national analysis, based on data from 40 states and Washington, D.C., found that since the pandemic the number of students who were chronically absent nearly doubled to about 13.6 million. "Specifically, between the 2018-19 and 2021-22 school years, the share of students chronically absent grew by 13.5 percentage points -- a 91-percent increase that implies an additional 6.5 million students are now chronically absent," said the study by Stanford University education professor Thomas Dee. The exact causes for the sharp spike in absenteeism were unclear, Dee said in his study, adding there's no evidence of linkage with sickness, enrollment loss, or COVID-related policies, such as mask mandates. "This suggests the sharp rise in chronic absenteeism reflects other important barriers to learning (e.g., declining youth mental health, academic disengagement) that merit further scrutiny and policy responses," said Dee. /IANS