Characteristics of daily illness absenteeism among primary and middle school students in Shenzhen

Objective To explore the epidemiological characteristics of daily illness absenteeism among primary and middle school students from 2011 to 2016.Methods School absenteeism data was collected from the Shenzhen Student Health Monitoring Information System.R software was used to make heat maps of the daily distribution of illness absenteeism.Results Overall,915 659 absent cases were drawn from the system during 2011-2016.Heat maps showed that daily distribution of illness absenteeism was not balanced in a whole year,highest in the first half of the year,especially in last two weeks of March.The most common reason of student absenteeism was cold or flu infection(61.79%).Four patterns were observed in daily distribution of absenteeism:month-centralized-type (including colds or flu,gastrointestinal disease,mumps and HFMD);annual-fluctuation-type (including bronchitis or pneumonia,chickenpox,eye and dental disease);annual-average-type (unintentional injury and rubella) and half-year-difference type (the ENT disease and the "no diagnosis" case).Conclusion Absenteeism is highest during the first half of a year,especially in March.Preventive measures should be taken accordingly to reduce sick leave in primary and middle schools.