Volume 16, Number 10—October 2010
Dispatch
Predicting Need for Hospitalization of Patients with Pandemic (H1N1) 2009, Chicago, Illinois, USA
Table 2
Clinical characteristics of nonhospitalized and hospitalized patients who had pandemic (H1N1) 2009 infection, Rush University Medical Center, Chicago, Illinois, USA, April 29–June 22, 2009*
Characteristic | Nonhospitalized patients, n = 51 | Hospitalized patients, n = 32 | ICU patients, n = 16 | Nonhospitalized vs. hospitalized patients |
ICU vs. non–ICU patients† |
|||
---|---|---|---|---|---|---|---|---|
p value | OR (95% CI) | p value | OR (95% CI) | |||||
Duration of ILI before evauulation, d, median (range) | 2 (0–7) | 3 (1–7) | 3 (1–7) | 0.15‡ | – | 0.20‡ | – | |
Subjective fever, no. (%) | 46 (90.2) | 27 (84.4) | 14 (87.5) | 0.50 | 0.59 (0.16–2.2) | 1.00 | 0.95 (0.18–5.0) | |
Headache, no. (%) | 18 (35.3) | 5 (15.6) | 1 (6.3) | 0.05§ | 0.34 (0.11–1.0) | 0.03 | 0.14 (0.02–1.1) | |
Cough, no. (%) | 50 (98.0) | 25/31 (80.7) | 14 (87.5) | 0.01 | 0.08 (0.01–0.73) | 0.62 | 0.57 (0.10–3.3) | |
Rhinorrhea, no. (%) | 40 (78.4) | 13/31 (41.9) | 7 (43.8) | 0.001§ | 0.20 (0.08-0.53) | 0.05§ | 0.34 (0.11–1.0) | |
Sore throat, no. (%) | 24 (47.1) | 2/31 (6.5) | 1 (6.3) | <0.0001§ | 0.08 (0.02–0.36) | 0.02§ | 0.11 (0.01–0.88) | |
Myalgia, no. (%) | 21 (41.2) | 6/31 (19.4) | 2 (12.5) | 0.04§ | 0.34 (0.12–0.98) | 0.053§ | 0.23 (0.05–1.1) | |
Dyspnea, no. (%) | 2 (3.9) | 15 (46.9) | 11(68.8) | <0.0001§¶ | 21.6 (4.5–104.4) | <0.0001¶ | 22.4 (5.8–86.2) | |
Nausea/vomiting, no. (%) | 14 (27.5) | 9/31 (29.0) | 4 (25.0) | 0.88§ | 1.1 (0.40–2.9) | 1.00 | 0.83 (0.24–2.9) | |
Obesity (BMI >30 or weight >95th percentile), no. (%) | 12/37 (32.4) | 11/22 (50.0) | 4/10 (40.0) | 0.18§ | 2.1 (0.71–6.2) | 1.00 | 1.1 (0.26–4.2) | |
Tachypnea, no. (%) | 9/49 (18.4) | 16/31 (51.6) | 10 (62.5) | 0.002§ | 4.7 (1.7–13.0) | 0.003§ | 5.4 (1.7–17.5) | |
O2 saturation, % (range) | 99 (96–100) | 95 (65–100) | 92 (65–100) | <0.0001‡¶ | – | <0.0001‡¶ | – | |
Hypoxia (SpO2 <92%), no. (%) | 0 | 10 (31.3) | 9 (56.3) | <0.0001 | – | <0.0001 | 84.9 (9.3–772.0) | |
Lymphopenia,# no. (%) | 9/12 (75.0) | 21 (65.6) | 10 (62.5) | 0.72 | 0.64 (0.14–2.80) | 0.54§ | 0.67 (0.18–2.5) | |
Thrombocytopenia,# no. (%) | 1/12 (8) | 8 (25.0) | 5 (31.3) | 0.41 | 3.70 (0.41–33.00) | 0.25 | 2.7 (0.6–12.2) | |
Acute renal failure,** no. (%) | 0 | 5 (15.6) | 4 (25.0) | 0.007 | – | 0.004 | 22.0 (2.3–214.2) | |
Infiltrate on chest radiograph, no. (%) | 0 | 11/29 (37.9) | 11 (68.9) | 0.001 | – | <0.0001 | – |
*p values by Fisher exact test except as indicated. Values given as no./no. indicate number of patients for whom results were available (if less than total no. patients in category). ICU, intensive care unit; OR, odds ratio; CI, confidence interval; ILI, influenza-like illness; –, not applicable; BMI, body mass index; SpO2, pulse oximeter oxygen saturation.
†Nonhospitalized patients + hospitalized patients not in ICU; n = 67.
‡Mann-Whitney U test.
§Pearson 2-sided χ2 test.
¶Significant on multivariate analysis.
#Lymphopenia <1,500 lymphocytes/mm3, thrombocytopenia <150,000 thrombocytes/mm3.
**Assuming that patients who did not have biochemical testing did not have acute renal failure.