Characteristics | All SARI patients (%) [n = 5,268]a | SARI patients with confirmed influenza (%) [n = 299]a | SARI patients without confirmed influenza (%) [n = 4,678]a | pvalue |
---|---|---|---|---|
Male sex | 3,091 (58.7) | 193 (64.5) | 2,725 (58.3) | 0.202 |
Age, median (interquartile range [IQR], years) | 12.0 (2.0-58.0) | 20.0 (3.0-67.0) | 11.0 (2.0-56.0) | 0.003 * |
Age group | ||||
<6 months | 357(6.8) | 11 (3.7) | 335 (7.2) | <0.001 * |
6 - 11 months | 392 (7.4) | 15 (5.0) | 362 (7.7) | |
12 - 23 months | 458 (8.7) | 24 (8.0) | 411 (8.8) | |
2 - 4 years | 928 (17.6) | 51 (17.1) | 836 (17.9) | |
5 - 9 years | 412 (7.8) | 37 (12.4) | 351 (7.5) | |
10 - 14 years | 137 (2.6) | 7 (2.3) | 125 (2.7) | |
15 - 49 years | 976 (18.5) | 38 (12.7) | 886 (18.9) | |
50 - 64 years | 554 (10.5) | 35 (11.7) | 476 (10.2) | |
≥65 years | 1050 (19.9) | 81 (27.1) | 896 (19.2) | |
Underlying chronic medical conditions | ||||
At least oneb | 1407 (26.7) | 111 (37.1) | 1296 (27.7) | <0.001 * |
Cardiovascular disease | 792 (15.0) | 64 (21.5) | 728 (15.6) | <0.001 * |
Chronic obstructive pulmonary diseasec | 198 (3.8) | 23 (7.7) | 175 (3.7) | 0.064 |
Diabetes mellitus | 244 (4.6) | 22 (7.4) | 222 (4.7) | 0.215 |
Chronic bronchitis | 205 (3.9) | 22 (7.4) | 183 (3.9) | 0.049 * |
Cancer/Tumor | 138 (2.6) | 13 (4.3) | 125 (2.7) | 0.043 * |
Asthma | 85 (1.6) | 2 (0.7) | 83 (1.8) | 0.040 * |
Vaccinated with seasonal influenza vaccine during past year | 47 (1.1) | 6 (2.7) | 41 (1.1) | 0.041 * |
Clinical history and physical examination | ||||
Fever | 4440 (84.3) | 284 (95.0) | 4156 (88.8) | <0.001 * |
Highest temperature after onset, median (interquartile range [IQR], °C) | 39.0 (38.5-39.5) | 39.0 (38.6-39.6) | 39.0 (38.5-39.5) | 0.072 |
Abnormal breath sounds on auscultation | 2950 (60.0) | 196 (65.6) | 2754 (58.9) | 0.071 |
Cough | 4235 (80.4) | 256 (85.6) | 3979 (85.1) | 0.592 |
Sore throat | 1661 (31.5) | 103 (34.4) | 1558 (33.3) | 0.028 * |
Difficulty breathing | 1449 (27.5) | 112 (37.5) | 1387 (29.6) | 0.012 * |
Clinical pneumonia | ||||
Abnormal chest X-ray performance | 2868 (54.4) | 176 (58.9) | 2692 (57.5) | 0.992 |
Diagnosis of clinical pneumonia | 1189 (22.6) | 66 (22.1) | 1123 (24.0) | 0.925 |
Clinical course, median (IQR), days | ||||
From illness onset to hospital admission | 3 (1–6) | 2.5 (1–5) | 3 (1–6) | 0.802 |
Length of stay in hospital | 8 (6–12.5) | 9 (6.75-14) | 8 (5–12) | 0.593 |
Admission to ICUd | 61 (1.2) | 5 (1.7) | 56 (1.2) | 0.840 |
Deathe | 98 (1.9) | 12 (4.0) | 86 (1.8) | 0.013 * |