TABLE 3.
Distribution of SARI criteria and other patient characteristics in patients with laboratory‐confirmed influenza A and B
| Studied variable |
Patients positive for influenza A (n = 93) |
Patients positive for influenza B (n = 56) |
Overall (n = 149) |
Statistical analysis |
|---|---|---|---|---|
| Fever | 87 (93.5%) | 54 (96.4%) | 141 (94.6%) | P = .711 |
| Feverishness | 3 (3.2%) | 11 (19.6%) | 14 (9.4%) | OR = 7.3, 95% CI: 2.0‐27.6, P = .002 |
| Malaise | 84 (90.3%) | 51 (91.1%) | 135 (90.6%) | P = 1.000 |
| Headache a | 64 (69.6%) | 33 (58.9%) | 97 (65.5%) | P = .214 |
| Myalgia | 68 (73.1%) | 38 (67.9%) | 106 (71.1%) | P = .576 |
| Altered clinical state | 63 (67.7%) | 35 (62.5%) | 98 (65.8%) | P = .593 |
| Cough | 89 (95.7%) | 54 (96.4%) | 143 (96.0%) | P = 1.000 |
| Odynophagia | 41 (44.1%) | 27 (48.2%) | 68 (45.6%) | P = .734 |
| Dyspnea | 65 (69.9%) | 38 (67.9%) | 103 (69.1%) | P = .855 |
| Smoking status | ||||
| Never smoked | 73 (78.5%) | 36 (64.3%) | 109 (73.2%) | P = .091 |
| Former smoker | 13 (14.0%) | 16 (28.6%) | 29 (19.5%) | |
| Current smoker | 7 (7.5%) | 4 (7.1%) | 11 (7.4%) | |
| Vaccinated against influenza in the current season | 6 (6.5%, 95% CI: 2.4%‐13.7%) | 1 (1.8%, 95% CI: 0.0%‐9.6%) | 7 (4.7%, 95% CI: 1.9%‐9.5%) | P = .254 |
| Comorbidities | ||||
| Patients with comorbidities b | 86 (92.5%) | 51 (91.1%) | 137 (91.9%) | P = .764 |
| Number of comorbidities, median (range) b | 2 (0‐4) | 2 (0‐4) | 2 (0‐4) | N/A |
| Frailty index, median (IQR) b | 0.2 (0.1, 0.3) | 0.2 (0.1, 0.3) | 0.2 (0.1, 0.3) | N/A |
| Cardiovascular disease c | 73 (78.5%) | 42 (76.4%) | 115 (77.7%) | P = .839 |
| Diabetes c | 33 (35.9%) | 20 (35.7%) | 53 (35.8%) | P = .999 |
| Obesity b | 23 (24.7%) | 18 (32.1%) | 41 (27.5%) | P = .348 |
| Chronic pulmonary disease c | 15 (16.3%) | 11 (19.6%) | 26 (17.6%) | P = .659 |
| Chronic liver disease d | 2 (2.2%) | 5 (8.9%) | 7 (4.7%) | P = .105 |
| Chronic kidney disease e | 5 (5.4%) | 6 (10.7%) | 11 (7.4%) | P = .333 |
| Hematologic cancer b | 4 (4.3%) | 1 (1.8%) | 5 (3.4%) | P = .651 |
| Non‐hematologic cancer b | 11 (11.8%) | 6 (10.7%) | 17 (11.4%) | P = .999 |
| Rheumatologic disease f | 9 (9.8%) | 2 (3.6%) | 11 (7.5%) | P = .211 |
| Immune suppression b | 0 (0.0%) | 1 (1.8%) | 1 (0.7%) | N/A |
| Antiviral treatment | 78 (83.9%) | 43 (76.8%) | 121 (81.2%) | P = .289 |
| Death during hospitalization g | 4 (4.3%, 95% CI: 1.2%‐10.6%) | 0 (0.0%, 95% CI: 0.0%‐6.4%) | 4 (2.7%, 95% CI: 0.7%‐6.7%) | P = .297 |
All data is presented as number (percentage), unless otherwise specified. Statistical analysis was performed with the two‐tailed chi‐squared test or Mann‐Whitney's U test. Frailty index was calculated by dividing the number of active comorbidities by the total number of comorbidities assessed for each patient.
Abbreviations: 95% CI, 95% confidence interval; N/A, not applicable; OR, odds ratio; SARI, severe acute respiratory infection.
Missing data for 1 patient.
Missing data for 2 patients.
Missing data for 4 patients.
Missing data for 3 patients.
Missing data for 5 patients.
Missing data for 7 patients.
Death occurred in 3 patients with influenza A/H1 and one with A/H3, all in the 2015/16 season. Four more deaths occurred in patients who tested negative for influenza in the 2017/18 season.