Table 3. Factors associated with LTBI seropositivity among prisoners, Tianjin, China*.

Factor	OR (95% CI)	aOR (96% CI)	p value by type 3 test
All age groups	1.79 (1.53–20.9)	1.67 (1.42–1.96)	<0.01
Ethnicity
Han	Referent	Referent	0.06
Other	1.61 (0.87–2.97)	1.90 (0.98–3.68)
Education
Primary school	Referent	Referent	0.76
Middle school	0.94 (0.7–1.25)	1.08 (0.79–1.48)
High school	0.86 (0.6–1.23)	0.95 (0.63–1.44)
Residency
Local	Referent	Referent	0.15
Migrant	1.09 (0.85–1.41)	1.22 (0.93–1.62)
Employment
No	Referent	Referent	0.94
Yes	1.14 (0.79–1.64)	0.98 (0.65–1.49)
BMI
Normal: 18.5–25.0	Referent	Referent	0.52
Abnormal: >25–<18.5	0.98 (0.74–1.29)	0.91 (0.67–1.22)
Contact history
No	Referent	Referent	0.97
Yes	1.09 (0.77–1.54)	1.01 (0.70–1.46)
Concurrent condition
No	Referent	Referent	0.49
Yes	1.45 (1.03–2.04)	1.14 (0.78–1.67)
Mycobacterium bovis BCG scar
No	Referent	Referent	0.04
Yes	1.44 (1.11–1.86)	1.33 (1.01–1.75)
History of incarceration
No	Referent	Referent	<0.01
Yes	2.34 (1.75–3.13)	2.01 (1.48–2.74)
Current duration of incarceration	1.11 (1.04–1.18)	1.15 (1.07–1.23)	<0.01
Facility-specific TB incidence, cases/100,000 population†
Low	Referent	Referent	<0.01
Median	1.26 (0.95–1.67)	1.13 (0.83–1.53)
High	1.76 (1.22–2.54)	1.87 (1.25–2.79)

*BMI, body mass index; LTBI, latent tuberculosis infection; TB, tuberculosis.
†The 2 low-incidence prisons reported 603.0 and 649.9 TB cases/100,000 persons, the 2 medium-incidence prisons 892.7 and 944.6 cases/100,000 persons, and the high-background prison 1,945.2 cases/100,000 persons.