Table 4.

Association Between Meteorological/Stream Flow Variables and Legionellosis

Variable	IRR (95% CI)a
5-mm increase in precipitation (2-wk lag)b	1.48 (1.38–1.59)
5% increase in relative humidity (2-wk lag)	1.24 (1.17–1.31)
1-SD increase in stream flow (2-wk lag)	1.26 (1.18–1.35)
5°C increase in maximum air temperature (1-wk lag)	0.81 (0.70–0.93)

Abbreviations: CI, confidence interval; IRR, incidence rate ratio; SD, standard deviation.

^aIRRs corresponding to the most significant lag period for each variable. IRRs were calculated from the univariate Poisson regression for each meteorological variable at each lead/lag period.

^bA 5-mm increase in precipitation with a 2-week lag had the lowest Akaike information criterion (AIC) score in the univariate analysis. See Supplementary Figure S4B for the complete list of corresponding AIC scores.