Table 2.

Analysis for influent factors of the positive rates of anti-HEV IgG among workers occupationally contacted with swine using logistic regression model.

Factors	Variables	β	Wald c2	P value	OR (95% CI)	Chi square test
Gender	1 = male, 0 = female	0.15	0.474	0.491	1.162 (0.759–1.779)
Age group (years)			24.699	0	2.067	χ2 = 14.649 P = 0.002
	1≦30 years	− 1.371	12.969	0	0.254 (0.120–0.535)
	2 = 31–40 years	− 0.824	6.551	0.01	0.439 (0.234–0.825)
	3 = 41–50 years	− 1.044	19.379	0	0.352 (0.221–0.560)
Years of Working			23.243	0	6	χ2 = 11.903 P = 0.018
	1 = 0–5 years,	− 3.007	13.445	0	0.049 (0.010–0.247)
	2 = 6–10 years,	− 2.772	11.946	0.001	0.063 (0.013–0.301)
	3 = 11–15 years,	− 2.986	13.313	0	0.050 (0.010–0.251)
	4 = 16–20 years,	− 1.576	2.881	0.09	0.207 (0.033–1.276)
Educational background			3.5	0.321	0.923	χ2 = 1.749 P = 0.417
	1 = Primary school	− 0.811	1.987	0.159	0.444 (0.144–1.373)
	2 = Junior school	− 0.483	0.769	0.381	0.617 (0.210–1.815)
	3 = Senior school	− 0.826	2.067	0.151	0.438 (0.142–1.350)
Job pattern			1.95	0.163	1.2	χ2 = 5.637 P = 0.060
	1 = pig farmers	1.713	7.134	0.068	5.545 (1.011–30.424)
	2 = Slaughters	2.396	3.89	0.049	10.984 (1.650–73.130)
	3 = Pork retailers	2.303	6.139	0.013	10.009 (1.533–65.349)
Working hours per day			2.214	0.331	1.506	χ2 = 8.077 P = 0.018
	1≦6 h	− 0.008	0	0.985	1.008 (0.452–2.247)
	2 = 7–9 h	− 0.398	1.012	0.315	0.670 (0.307–1.462)