Correlations between initial cytokine/chemokine concentrations and clinical parameters at presentation (temperature, respiratory rate, oxygen saturation) and the clinical outcomes (hospital length-of-stay, ICU admission).

For correlations with temperature, respiratory rate, oxygen saturation, and length-of-stay, the Spearman's rank coefficients (rho) were shown. For risk of ICU admission, the adjusted odds ratio and the 95% confidence interval (CI) per log10 unit increase in cytokine concentration were shown (adjusted for age, comorbidity and time from onset). Data on respiratory rate was incomplete in seasonal influenza cases, and there were too few ICU admissions to allow meaningful analysis.*p**p