The association between tuberculin skin test result and active tuberculosis risk of college students in Beijing, China: a retrospective cohort study

Table 1 Baseline characteristics of students

Year	Enrollment of freshmen	# of follow-up	Sex		Age (means ± SD)	TST positive(%)	Strong TST positive(%)
Year	Enrollment of freshmen	# of follow-up	Male(%)	Female(%)	Age (means ± SD)	TST positive(%)	Strong TST positive(%)
2013	14899	14592	45.59	54.41	19.78 ± 1.53	10.85	5.10
2014	20081	19823	51.70	48.30	19.52 ± 1.13	10.60	4.61
2015	18914	18659	58.63	41.37	19.37 ± 0.95	13.53	6.92
2016	14394	14218	59.86	40.14	19.35 ± 1.04	12.74	6.54
Total	68288	67292	54.02	45.98	19.52 ± 1.26	11.92	5.76

TST positive: induration size ≥10 mm or the presence of blister or necrosis
Strong TST positive: induration size ≥15 mm or the presence of blister or necrosis

ISSN: 1471-2334