Aa: Absenteeism

n.

1. Habitual failure to appear, especially for work or other regular duty.

2. The rate of occurrence of habitual absence from work or duty.

The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company. Updated in 2003. Published by Houghton Mifflin Company. All rights reserved.

For example, it recommends that schools stay open during a pandemic and develop school-based surveillance systems for absenteeism of students and sick-leave policies for staff and students.

Pandemic influenza school closure policies by Kahn, Laura H. / Emerging Infectious Diseases