Volume 17, Number 8—August 2011
Research
Case–Control Study of Risk Factors for Hospitalization Caused by Pandemic (H1N1) 2009
Kate A. Ward, Paula J. Spokes
, and Jeremy M. McAnulty
, and Jeremy M. McAnultyTable 4
Comparison of characteristics of patients with cases of pandemic (H1N1) 2009 influenza by time from symptom onset to medical attention, Sydney, Australia, 2009*
| Patient characteristic |
Medical attention within 48 h | OR (95% CI) |
p value |
|
|---|---|---|---|---|
| Yes, no. (%) patients, n = 235 |
No, no. (%) patients, n = 60 |
|||
| Sex | ||||
| M | 97 (41) | 24 (40) | ||
| F |
138 (59) |
36 (60) |
1.1 (0.6–1.9) |
0.8576 |
| Age, y | ||||
| 16–25 | 33 (14) | 5 (8) | 1.1 (0.3–4.3) | |
| 26–35 | 44 (19) | 9 (15) | 0.8 (0.3–2.8) | |
| 36–45 | 47 (20) | 11 (18) | 0.7 (0.2–2.3) | |
| 46–55 | 50 (21) | 20 (33) | 0.4 (0.1–1.3) | |
| 56–65 | 32 (14) | 10 (17) | 0.6 (0.2–1.8) | |
| >65 |
29 (12) |
5 (8) |
0.3677 |
|
| Aboriginal status | ||||
| Nonindigenous | 229 (97) | 58 (97) | 0.7409 | |
| Indigenous |
6 (3) |
2 (3) |
0.8 (0.1–3.9) |
|
| Body mass index† | ||||
| Underweight (<18.5) | 13 (6) | 2 (3) | 1.6 (0.3–7.8) | |
| Normal (18.5–24.9) | 65 (28) | 16 (27) | 0.4457 | |
| Overweight (25.0–29.9) | 67 (29) | 10 (17) | 1.6 (0.7–3.9) | |
| Obese 1 (30–34.9) | 38 (16) | 12 (20) | 0.8 (0.3–1.8) | |
| Obese 2 (35–39.9) | 23 (10) | 6 (10) | 0.9 (0.3–2.7) | |
| Obese 3 (>40) |
19 (8) |
8 (13) |
0.6 (0.2–1.6) |
|
| Health condition‡ | ||||
| Asthma | 89 (38) | 24 (40) | 0.3607 | |
| No regular medication | 16 (7) | 9 (15) | ||
| Regular medication | 73 (31) | 15 (25) | 1.4 (0.7–2.6) | |
| Heart disease§ | 31 (13) | 7 (12) | 1.2 (0.5–2.8) | 0.703 |
| Kidney disease | 8 (3) | 2 (3) | 1.0 (0.2–4.9) | 0.9785 |
| Mental health problem | 34 (14) | 17 (28) | 0.4 (0.2–0.8) | 0.0129 |
| Neurologic problem | 14 (6) | 8 (13) | 0.4 (0.2–1.0) | 0.0586 |
| Immunosuppression | 22 (9) | 6 (10) | 0.9 (0.4–2.4) | 0.8803 |
| Obstructive sleep apnea | 26 (11) | 10 (17) | 0.6 (0.3–1.4) | 0.2399 |
| Lung disease | 46 (20) | 11 (18) | 1.1 (0.5–2.2) | 0.828 |
| Diabetes | 48 (20) | 10 (17) | 1.3 (0.6–2.7) | 0.5141 |
| Liver disease | 16 (7) | 5 (8) | 0.8 (0.3–2.3) | 0.6823 |
| Pregnancy |
33 (14) |
7 (12) |
1.3 (0.5–3.2) |
0.6008 |
| Smoking status¶ | ||||
| Nonsmoker | 113 (48) | 26 (43) | ||
| Current or former smoker |
121 (51) |
34 (57) |
0.8 (0.5–1.5) |
0.493 |
| Influenza vaccine in 2009# | 86 (37) | 19 (32) | 1.3 (0.7–2.3) | 0.4507 |
*OR, odds ratio; CI, confidence interval.
†Data missing for 10 case-patients who received medical attention within 48 h and 6 who did not.
‡Groups are not mutually exclusive.
§Data were missing for 6 case-patients who received medical attention within 48 h.
¶Data were missing for 1 case-patient who received medical attention within 48 h.
#Vaccination information was missing for 2 case-patients and 1 control.
