Table 5. Short-term associations between influenza A and B and IPD according to case-crossover methods.

Lag (wk)	Odds Ratio	95% Confidence Interval	p-Value
0	1.05	0.97–1.13	0.20
−1	1.10	1.02–1.18	0.01
−2	1.00	0.93–1.09	0.90
−3	0.93	0.86–1.01	0.07
−4	1.02	0.94–1.11	0.65

Data are presented as odds ratios with 95% confidence intervals for 1 IPD case per 100 influenza cases.