Age as a Leading Indicator: A Multi-Outcome Analysis of Influenza Lead-Lag Relationships

Prior work has shown that school-age children's influenza activity precedes that of adults by one to two weeks. Whether this is robust across outcomes or constant across a season's course is unexamined. Using electronic health record data from two health systems in South Carolina (2016-2026) on individuals with an influenza diagnosis or positive test, we tested age-group lead-lag relationships across six measures using differenced cross-correlation and Granger causality, with significance confirmed via heteroskedasticity-robust block permutation. We tested whether relationships differed betwee

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