Results
School districts reported 2,184,220 all-cause absences (2010-2015).
Three one-season studies reported 19,577 all-cause and 3,012 ILI-related
absences (2007, 2012, 2015). Over seven seasons, 11,946 confirmed
influenza cases were reported. Absences improved seasonal model fits and
predictions. Multivariate models using elementary school absences
outperformed middle and high school models (relative mean absolute error
(relMAE)=0.94, 0.98, 0.99). K-5 grade-specific absence models had lowest
mean absolute errors (MAE) in cross-validations. ILI-specific absences
performed marginally better than all-cause absences in two years,
adjusting for other covariates, but markedly worse one year.