Association of Prodromal Type 1 Diabetes With School Absenteeism of Danish Schoolchildren: A Population-Based Case-Control Study of 1,338 Newly Diagnosed Children

OBJECTIVE To investigate school absenteeism before the clinical diagnosis of type 1 diabetes in children who develop the disease. RESEARCH DESIGN AND METHODS This population-based, retrospective case-control study involved all Danish children who developed type 1 diabetes and attended public schools (n = 1,338) from 2010 to 2017. Those children were matched at a 1-to-5 ratio, on the basis of sex and date of birth, to children without diabetes (n = 6,690). Case and control absenteeism were compared monthly, starting with 12 months prior to the type 1 diabetes diagnosis through 12 months after diagnosis. RESULTS Before the diabetes diagnosis (7–12 months), the mean number of days absent from school per month was 0.93 (SD 1.78) among children with diabetes and 0.93 (1.82) among control children (difference −0.004 days, P = 0.94). From 4 months before the diagnosis, children who developed diabetes had a statistically significant increase in absenteeism compared with control children (difference 0.24 days, P < 0.05). CONCLUSIONS Children who were diagnosed with type 1 diabetes had increased school absenteeism 4 months before diagnosis.