Table 1. The Demographic Characteristics of the SARS Patients and Controls.

	Guangzhou Non-HCW Population			Beijing Population			HCW Population
	SARS patients	Controls	P	SARS patients	Controls	P	SARS patients	Controls	P
	(N = 67) No. (%)	(N = 192) No. (%)		(N = 624) No. (%)	(N = 791) No. (%)		(N = 40) No. (%)	(N = 122) No. (%)
Sex
Male	29 (43.28)	99 (51.56)	0.24	312 (50.00)	412 (52.09)	0.44	3 (7.50)	12 (9.84)	0.66
Female	38 (56.72)	93 (48.44)		312 (50.00)	379 (47.91)		37 (92.50)	110 (90.16)
Age, y
16–30	21 (31.34)	57 (29.69)	0.78	253 (40.54)	339 (42.86)	0.26	29 (72.50)	85 (69.67)	0.96
31–40	23 (34.33)	58 (30.21)		152 (24.36)	163 (20.61)		9 (22.50)	31 (25.41)
41–50	13 (19.40)	49 (25.52)		131 (21.00)	159 (20.10)		1 (2.50)	4 (3.28)
>50	10 (14.93)	28 (14.58)		88 (14.10)	130 (16.43)		1 (2.50)	2 (1.64)

P was calculated using the χ² test.