†The week-only model included only week of the year
and absence models included weekly lagged absence rates from the
previous week, week of the year, and average temperature.‡SMART models included weekly lagged absence rates and
week of the year. cCross-validation used leave 20% of
schools out. Abbreviations: ∆AICc: change in corrected Akaike’s
Information Criterion; ILI: influenza-like-illness; MAE: mean absolute
error; PIPP: Pittsburgh Influenza Prevention Project; SMART: Social
Mixing and Respiratory Transmission in Schools study; SMART2:
Surveillance, Monitoring of Absences & Respiratory Transmission Study;
R2: coefficient of determination.