Table 2.
Factors associated with ICU admission in hospitalized severe influenza patients.
| ICU admission (N = 217) |
No ICU admission (N = 1089) | Crude OR (95% CI) | P value | Adjusted OR (95% CI) | P value | |
|---|---|---|---|---|---|---|
| Age | ||||||
| < 15 years | 6 (2.8%) | 49 (4.5%) | 0.28 (0.11–0.74) | 0.01 | 0.29 (0.11–0.76) | 0.01 |
| 15–49 years | 34 (15.7%) | 103 (9.5%) | Ref | Ref | ||
| 50–64 years | 79 (36.4%) | 183 (16.8%) | 1.30 (0.79–2.13) | 0.30 | 1.17 (0.71–1.94) | 0.53 |
| 65–74 years | 37 (17.1%) | 230 (21.1%) | 0.50 (0.29–0.86) | 0.01 | 0.41 (0.23–0.74) | < 0.01 |
| ≥ 75 years | 61 (28.1%) | 524 (48.1%) | 0.39 (0.24–0.64) | < 0.01 | 0.30 (0.17–0.53) | < 0.01 |
| Sex | ||||||
| Female | 81 (37.3%) | 482 (44.3%) | Ref | Ref | ||
| Male | 136 (62.7%) | 607 (55.7%) | 1.36 (0.99–1.86) | 0.05 | 1.31 (0.95–1.81) | 0.10 |
| Size of municipality | ||||||
| ≤ 10.000 inhabitants | 41 (18.9%) | 126 (11.6%) | 1.33 (0.86–2.07) | 0.20 | 1.48 (0.94–2.33) | 0.09 |
| > 10.000 inhabitants | 176 (81.1%) | 963 (88.4%) | Ref | Ref | ||
| Comorbidities | ||||||
| 1 | 70 (32.3%) | 339 (31.1%) | 1.06 (0.70–1.63) | 0.77 | 1.14 (0.72–1.76) | 0.60 |
| ≥ 2 | 101 (46.5%) | 552 (47.9%) | 0.97 (0.65–1.45) | 0.90 | 1.08 (0.76–1.84) | 0.46 |
| No | 46 (21.2%) | 228 (20.9%) | Ref | Ref | ||
| COPD | ||||||
| Yes | 60 (27.6%) | 280 (25.7%) | 1.09 (0.77–1.54) | 0.63 | 1.11 (0.76–1.60) | 0.60 |
| No | 157 (72.4%) | 809 (74.3%) | Ref | Ref | ||
| Morbid obesity | ||||||
| Yes | 23 (10.6%) | 69 (6.3%) | 1.87 (1.08–3.22) | 0.02 | 1.66 (0.95–2.89) | 0.07 |
| No | 194 (89.4%) | 1020 (93.7%) | Ref | Ref | ||
| Diabetes | ||||||
| Yes | 59 (27.2%) | 269 (24.7%) | 1.15 (0.81–1.62) | 0.43 | 1.24 (0.87–1.78) | 0.23 |
| No | 158 (72.8%) | 820 (75.3%) | Ref | Ref | ||
| Chronic renal disease | ||||||
| Yes | 28 (12.9%) | 194 (17.8%) | 0.65 (0.42–1.01) | 0.06 | 0.78 (0.48–1.25) | 0.30 |
| No | 189 (87.1%) | 895 (82.2%) | Ref | Ref | ||
| Immune deficiency | ||||||
| Yes | 33 (15.2%) | 175 (16.1%) | 0.91 (0.60–1.38) | 0.65 | 0.86 (0.56–1.33) | 0.50 |
| No | 184 (84.8%) | 914 (83.9%) | Ref | Ref | ||
| Chronic cardiovascular disease | ||||||
| Yes | 79 (36.4%) | 416 (38.2%) | 0.98 (0.71–1.34) | 0.90 | 1.12 (0.78–1.59) | 0.54 |
| No | 138 (63.6%) | 673 (61.8%) | Ref | Ref | ||
| Chronic liver disease | ||||||
| Yes | 24 (11.1%) | 52 (4.8%) | 2.01 (1.18–3.42) | 0.01 | 1.75 (1.01–3.06) | 0.05 |
| No | 193 (88.9%) | 1037 (95.2%) | Ref | Ref | ||
| Other comorbiditiesa | ||||||
| Yes | 28 (12.9%) | 145 (13.3%) | 0.82 (0.52–1.29) | 0.39 | 0.92 (0.58–1.47) | 0.74 |
| No | 189 (87.1%) | 944 (86.7%) | Ref | Ref | ||
| Pregnancy | ||||||
| Yes | 2 (0.9%) | 5 (0.5%) | 1.84 (0.33–10.31) | 0.49 | 1.74 (0.31–9.80) | 0.53 |
| No | 215 (99.1%) | 1084 (99.5%) | Ref | Ref | ||
| Length of stay | ||||||
| 0–6 days | 26 (12.0%) | 481 (44.2%) | Ref | Ref | ||
| ≥ 7 days | 191 (88.0%) | 608 (55.8%) | 6.68 (4.30–10.38) | < 0.01 | 6.54 (4.17–10.24) | < 0.01 |
| Type of virus | ||||||
| A | 92 (42.4%) | 426 (39.1%) | 1.20 (0.88–1.64) | 0.24 | 1.14 (0.83–1.57) | 0.41 |
| B | 125 (57.6%) | 663 (60.9%) | Ref | Ref | ||
| Seasonal vaccine | ||||||
| Yes | 52 (24.1%) | 393 (36.3%) | 0.62 (0.44–0.88) | < 0.01 | 0.80 (0.55–1.16) | 0.24 |
| No | 164 (75.9%) | 690 (63.7%) | Ref | Ref | ||
| NAI treatment | ||||||
| Yes | 202 (93.1%) | 991 (91.0%) | 1.90 (1.06–3.41) | 0.03 | 2.12 (1.19–4.13) | 0.01 |
| No | 15 (6.9%) | 98 (9.0%) | Ref | Ref | ||
| NAI treatment | ||||||
| ≤ 48 h symptom onset | 60 (28.8%) | 415 (38.9%) | 1.55 (0.83–2.92) | 0.17 | 1.83 (0.94–3.57) | 0.07 |
| > 48 h symptom onset | 133 (63.9%) | 553 (51.9%) | 2.02 (1.11–3.66) | 0.02 | 2.38 (1.26–4.49) | 0.01 |
| No | 15 (7.2%) | 98 (9.2%) | Ref | Ref | ||
| Pneumonia | ||||||
| Yes | 151 (69.6%) | 680 (62.6%) | 0.65 (0.44–0.94) | 0.02 | 0.61 (0.41–0.89) | 0.01 |
| No | 66 (30.4%) | 406 (37.4%) | Ref | Ref | ||
| Nosocomial infection | ||||||
| Yes | 22 (10.2%) | 120 (11.0%) | 1.16 (0.68–1.99) | 0.58 | 1.08 (0.62–1.88) | 0.79 |
| No | 194 /89.8%) | 969 (89.0%) | Ref | Ref | ||
COPD: chronic obstructive pulmonary disease, NAI: neuraminidase inhibitors.
aHemoglobinopathy, severe neuromuscular disease or cognitive dysfunction.