Table 2. Univariate and multivariate analyses of the protective and risk factors for incident TB among elderly persons with and without influenza vaccination, Taiwan, 2005–2012*.

Characteristic	Person-years	Incidence density†	Univariate analysis, HR (95% CI)	Multivariate analysis, adjusted HR (95% CI)
Influenza vaccination
No	227,910.5	175.5	1	1
Yes	510,458.1	145.2	0.83 (0.73–0.93)‡	0.82 (0.73–0.93)‡
Age, y
65–69	293,257.6	106.4	1	1
70–74	197,971.8	150.5	1.41 (1.21–1.66)§	1.18 (1.00–1.38)¶
>75	247,139.3	214.9	2.02 (1.75–2.32)§	1.43 (1.24–1.66)§
Sex
F	385,893.5	62.7	1	1
M	352,475.2	255.1	4.07 (3.53–4.69)§	3.32 (2.88–3.84)§
Income level
Low	507,842.5	170.9	1	1
Intermediate	133,417.7	122.9	0.72 (0.61–0.85)§	0.88 (0.74–1.04)
High	97,108.5	112.2	0.66 (0.54–0.80)§	0.82 (0.67–1.00)
Urbanization
Urban	187049.0	129.4	1	1
Suburban	436275.1	157.9	1.22 (1.05–1.41)‡	1.13 (0.98–1.31)
Rural	115044.5	182.5	1.41 (1.17–1.70)§	1.37 (1.13–1.65)¶
Concurrent conditions
Diabetes
No	596,098.4	153.5	1	1
Yes	142,270.2	158.9	1.03 (0.89–1.20)	1.17 (1.02–1.33)¶
CHF
No	708,633.3	152.4	1	1
Yes	29,735.4	205.1	1.34 (1.04–1.74)¶	1.37 (1.16–1.62)§
COPD
No	621,742.5	133.3	1	1
Yes	116,626.2	267.5	2.00 (1.76–2.28)§	2.77 (2.43–3.15)§
Asthma
No	676,539.1	145.9	1	1
Yes	61,829.5	249.1	1.71 (1.44–2.02)§	1.12 (0.96–1.30)
CVD
No	631659.3	152.0	1	1
Yes	106709.3	169.6	1.11 (0.95–1.31)	0.89 (0.78–1.02)
HTN
No	360268.3	156.5	1	1
Yes	378100.3	152.6	0.97 (0.87–1.09)	0.86 (0.76–0.98)¶
CKD
No	693223.9	149.2	1	1
Yes	45144.7	237.0	1.59 (1.30–1.94)§	1.31 (1.12–1.53)§
Cancer
No	696681.8	150.9	1	1
Yes	41686.8	215.9	1.43 (1.15–1.77)‡	1.96 (1.71–2.26)§

*CHF, congestive heart failure; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; CVD, cerebrovascular disease; HR, hazard ratio; HTN, hypertension; TB, tuberculosis.
†Per 100,000 person-years.
‡p<0.01.
§p<0.001.
¶p<0.05.