Table 1

Comparisons of major socio-demographic characteristics between the study participants and the Hong Kong population 2009

	Study participants n %		Hong Kong population (2009)† n %		p Value of χ² test
Gender (N=6561)					0.042
Male	3173	48.4	3 284 800	47.7
Female	3388	51.6	3 688 000	52.3
Age (years, N=6503)					<0.001
0–14	887	13.6*	863 800	12.4*
15–24	906	13.9*	885 400	12.7*
25–44	2070	31.8*	2 236 90	32.1*
45–64	1837	28.2*	2 088 100	29.9*
≥65	803	12.3*	898 600	12.9*
Education in population aged 15 or above(N=5559)					<0.001
Primary or below	932	16.8*	1 589 800	22.8*
Secondary	2.994	53.9*	3 611 900	51.8*
Postsecondary‡	1633	29.4*	1 771 100	25.4*
Occupation in working population (N=2873)					<0.001
White-collar job§	2376	82.7*	2 351 200	67.7*
Blue-collar job¶	462	16.1*	1 111 500	32.0*
Others	35	1.2*	5000	0.1*

*Significant difference reached in the χ² test by using the actual number of population. Bonferroni correction was applied to correct multiple testing. A significance level of a=0.0125 (0.05/4) was therefore adopted.
†Data sources: Hong Kong annual digest of statistics 2012 edition.
‡Postsecondary education included non-degree and degree courses.
§White-collar job: including manager and administrators, professionals, associate professionals, clerical support workers and service and sales workers.
¶Blue-collar job: including craft and related workers, plant and machine operators, elementary occupations and skilled agricultural and fishery workers.