Table 1.
Characteristics of hospitalized severe, acute respiratory infection (SARI) patients and laboratory-confirmed influenza patients in four surveillance hospitals in Jingzhou, China, April 5, 2010 to April 8, 2012
| Characteristics | All SARI patients (%) [n = 17 172]* | SARI patients with confirmed influenza (%) [n = 2057]* | SARI patients without confirmed influenza (%) [n = 14 151]* | P value** |
|---|---|---|---|---|
| Male sex | 5867 (34) | 1195 (58) | 8097 (57) | 0·453 |
| Age, median [interquartile range (IQR), years] | 2·2 (1·0–4·4) | 2·9 (1·2–6·0) | 2 (1·0–4·1) | |
| Age group | ||||
| <6 months | 1318 (8) | 156 (8) | 1099 (8) | |
| 6–11 months | 3121 (18) | 263 (13) | 2684 (19) | |
| 12–23 months | 3596 (21) | 339 (17) | 3042 (22) | |
| 2–4 years | 5318 (31) | 669 (33) | 4361 (31) | |
| 5–9 years | 1710 (10) | 300 (15) | 1300 (9) | |
| 10–14 years | 319 (2) | 49 (2) | 242 (2) | |
| 15–49 years | 617 (4) | 93 (5) | 495 (4) | |
| 50–64 years | 454 (3) | 77 (4) | 360 (3) | |
| ≥65 years | 719 (4) | 111 (5) | 568 (4) | |
| Underlying chronic medical conditions | ||||
| At least one*** | 1200 (7) | 184 (9) | 951 (7) | <0·001 |
| Chronic obstructive pulmonary disease† | 148 (0·9) | 27 (1) | 111 (0·8) | 0·015 |
| Asthma | 101 (0·6) | 20 (1) | 77 (0·5) | 0·019 |
| Cardiovascular disease | 116 (0·7) | 20 (1) | 88 (0·6) | 0·068 |
| Diabetes mellitus | 86 (0·5) | 12 (0·6) | 71 (0·5) | 0·628 |
| Children <2 years†† | ||||
| Low birth weight††† | 82/8035 (1) | 13/758 (2) | 67/6825 (1) | 0·061 |
| Premature birth‡ | 117/8035 (2) | 17/758 (2) | 97/6825 (1) | 0·078 |
| Clinical history and physical examination | ||||
| Temperature ≥38°C | 10 279 (60) | 1319 (64) | 8393 (59) | 0·001‡‡ |
| Abnormal breath sounds on auscultation | 5610 (33) | 715 (35) | 4611 (33) | 0·050 |
| Cough | 10 240 (60) | 1408 (68) | 8284 (59) | <0·001 |
| Sore throat | 4444 (26) | 461 (22) | 3794 (27) | <0·001 |
| Runny nose | 2279 (13) | 341 (17) | 1811 (13) | <0·001 |
| Sputum production | 2188 (13) | 307 (15) | 1750 (12) | 0·001 |
| Difficulty breathing | 892 (5) | 93 (5) | 740 (5) | 0·174 |
| Documented tachypnea‡‡‡ | 255 (2) | 36 (2) | 207 (2) | 0·316 |
| Chest pain | 143 (0·8) | 17 (0·8) | 125 (0·9) | 0·796 |
| Hemoptysis | 77 (0·4) | 12 (0·6) | 60 (0·4) | 0·310 |
| Vomiting | 913 (5) | 74 (4) | 767 (5) | <0·001 |
| Diarrhea | 635 (4) | 30 (2) | 564 (4) | <0·001 |
| Abdominal pain | 254 (2) | 29 (1) | 209 (2) | 0·813 |
| Clinical pneumonia | 4885 (28) | 576 (28) | 4062 (29) | 0·510 |
| Chest X-ray performed | 8486 (49) | 1066 (52) | 6903 (49) | 0·010 |
| The presence of radiographic diagnosis of pneumonia | 3814/8486 (45) | 430/1066 (40) | 3180/6903 (46) | <0·001 |
| Clinical course, median (IQR), days | ||||
| From illness onset to hospital admission | 2 (0–3) | 2 (0–3) | 2 (0–3) | 0·343 |
| Length of stay in hospital | 5 (4–7) | 5 (4–7) | 5 (4–7) | 0·469 |
| Admission to ICU§ | 154 (0·9) | 22 (1) | 126 (0·9) | 0·425 |
| Death§§ | 62 (0·4) | 8 (0·4) | 51 (0·4) | 0·841 |
Data are presented as no. (%) of patients unless otherwise indicated. Denominators for testing of fewer cases than full group are indicated. Percentages may not total 100 because of rounding. There are a certain proportion of case-patients with no influenza testing results, so patients with and without confirmed influenza are not total SARI patients.
The P-values are comparisons between ‘SARI patients with confirmed influenza’ and ‘SARI patients without confirmed influenza’.
Atleast one underlying medical condition defined as: an inpatient stays with admission diagnosis in any of the following disease, symptoms or signs: chronic obstructive pulmonary disease, asthma, cardiovascular disease, diabetes chronic metabolic disease, or renal dysfunction.
Chronic obstructive pulmonary disease defined as: a lung disease characterized by chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible.
Denominator is patients <2 years old with complete information for this variable.
Low birth weight defined as a weight of <2500 g (up to and including 2499 g), irrespective of gestational age.
Premature birth defined as a birth that takes place before 37 weeks of gestation have passed.
Compare with patients with normal temperature.
Documented tachypnea defined as: elevated respiratory rate in different age groups: (i) Age < 2 months: >60 breaths/minute; (ii) Age 2–11 months: >50 breaths/minute; (iii) Age 12 months to <5 years: >40 breaths/minute; and (iv) Age ≥5 years: >25 breaths/minute.
ICU denotes intensive care unit.
During hospitalization or up to 30 days after hospital discharge.