The Journal of School Nursing, 2004. Asthma, the most common chronic disease in children today, is the leading cause of absenteeism among students. It accounts for nearly 20 million lost school days annually. This study examined whether full-time (5 days per week) or part-time (2 days per week) school nurses would have a differential effect on the frequency of absences among elementary school students with asthma. This study found that students with asthma who were poor or who were African American and in schools with full-time nurses missed significantly fewer days (3 days, or 23% fewer missed days) than did their counterparts with asthma in schools with part-time nurses.