Table 2

Univariate and multivariate analysis of demographic, professional and clinical characteristics associated with TST positivity in a cohort of ISP workers (n=4225)

				Univariate analysis		Multivariate analysis
Variables	Overall	TST positive result	% (95% CI)	OR (95% CI)	p Value	OR (95% CI)	p Value
Age (per year increase)				1.07 (1.05 to 1.09)	<0.001	1.07 (1.05 to 1.10)	<0.001
Gender
Female	763	72	9.4 (7.5 to 11.8)	Reference		Reference
Male	3462	346	10.0 (9.0 to 11.1)	1.07 (0.8 to 1.4)	0.6	1.19 (0.86 to 1.68)	0.3
Place of birth
Italy	3913	377	9.6 (8.7 to 10.6)	Reference		Reference
Foreign	95	20	21.1 (13.4 to 30.6)	2.5 (1.5 to 4.1)	0.001	1.55 (0.73 to 2.99)	0.2
Place of birth (within Italy)
North	839	99	11.8 (9.7 to 14.2)	1.4 (1.1 to 1.8)	0.02
Centre	707	67	9.5 (7.5 to 11.9)	1.1 (0.8 to 1.4)	0.6
South	2367	211	8.9 (7.8 to 10.2)	Reference
Educational level
Lower secondary school	549	72	13.1 (10.5 to 16.2)	Reference		Reference
Upper secondary school	2250	207	9.2 (8.1 to 10.5)	0.7 (0.5 to 0.9)	0.008	0.98 (0.72 to 1.36)	0.93
Higher education	396	30	7.6 (5.4 to 10.6)	0.5 (0.3 to 0.8)	0.006	0.66 (0.40 to 1.08)	0.10
Length of service (per year increase)				1.06 (1.05 to 1.08)	<0.001
Work category
1	507	51	10.1 (7.7 to 13.0)	0.53 (0.33 to 0.85)	0.009	0.54 (0.28 to 1.0)	0.049
2	1027	94	9.2 (7.5 to 11.1)	0.48 (0.31 to 0.74)	0.001	0.52 (0.32 to 0.84)	0.008
3	2062	192	9.3 (8.1 to 10.6)	0.49 (0.33 to 0.73)	0.001	0.54 (0.34 to 0.86)	0.01
4	434	47	10.8 (8.2 to 14.1)	0.58 (0.36 to 0.93)	0.025	0.55 (0.32 to 0.94)	0.03
5	195	34	17.4 (12.8 to 23.4)	Reference		Reference
Previous BCG vaccination
No	4111	335	8.1 (7.4 to 9.0)	Reference		Reference
Yes	114	83	72.8 (64.0 to 80.1)	30.2 (19.9 to 46.9)	<0.001	21.0 (12.9 to 34.9)	<0.001

ISP, Italian State Police; OECD, Organization for Economic Co-operation and Development; TST, tuberculin skin test.