In multivariate logistic regression (Tables 14 and 15), the absence of pleural effusion in adults was associated with detection of respiratory viruses (odds ratio [OR] 0.31, 95% confidence interval [CI] 0.12–0.80). For children, the lack of multilobar infiltrates was a significant predictor of respiratory virus detection (OR 0.22, 95% CI 0.06–0.81).Table 14Prediction of respiratory virus detection for adult patients Univariable analysis Multivariable analysis Predictor p-value OR (95% CI) p-value OR (95% CI) Neutropenia0.013.46 (1.32–9.07)0.272.11 (0.56–7.89) Hematologic malignancy0.042.25 (1.02–4.97)0.591.35 (0.45–4.01) Pleural effusion0.020.36 (0.15–0.86)0.020.31 (0.12–0.80) Platelets (minimum), G/l0.021.00 (0.99–1.00)0.201.00 (0.99–1.00) Table 15Prediction of respiratory virus detection for pediatric patients Univariable analysis Multivariable analysis Predictor p-value OR (95% CI) p-value OR (95% CI) Neutropenia0.067.75 (0.92–65.66)0.107.44 (0.69–80.42) Multilobular infiltrates0.030.31 (0.11–0.91)0.020.22 (0.06–0.81) White blood cells (maximum), G/l0.020.94 (0.89–0.99)0.100.95 (0.90–1.01) OR odds ratio, CI confidence interval