Table 1.

Demographic and Clinical Profiles of Patients With Severe Cases and Controls With Mild A(H1N1)pdm09 Infection

Patient Profile	Patients, No. (%)a		P Valuec
	Severe Infection (n = 162)b	Mild Infection (n = 247)
Demographic characteristic
Age, median years (interquartile range)	56 (45–65)	40 (25–55)	<.001
Female	64 (39.5)	142 (57.5)	<.001
Risk conditions
Age ≥65 y	43 (26.5)	35 (14.2)	.003
Pregnancy	1 (0.6)	8 (3.2)	.094
Chronic pulmonary disease	49 (30.2)	24 (9.7)	<.001
Chronic cardiac disease	36 (22.2)	26 (10.5)	.002
Metabolic disorders	47 (29.0)	35 (14.2)	<.001
Chronic renal disease	18 (11.1)	13 (5.3)	.035
Chronic hepatic disease	5 (3.1)	8 (3.2)	>.99
Neurological conditions	23 (14.2)	17 (6.9)	.017
Hemoglobinopathy	1 (0.6)	2 (0.8)	>.99
Immunosuppression	23 (14.2)	40 (16.2)	.675
Obesity	27 (16.7)	3 (1.2)	<.001

^a Data represent No. (%) of patients unless otherwise stated.

^b Among patients with severe illness, 26 died.

^c The Fisher exact test and Mann–Whitney U test were used for categorical and continuous variables, respectively.