TABLE 3.

Results of Multivariable Poisson Regression Analysis of Invasive Bacterial Pneumonia Incidence in Adults, by Age, Race/Ethnicity, and Percentage of Census Tract Poverty: ABCs Areas, United States, 2003–2004

Variable by Age	ARR (95% CI)
Race/Ethnicity
Adults aged 18–34 y
White, non-Hispanic (Ref)	1.00
Black, non-Hispanic	2.93 (2.26, 3.79)
Hispanic	1.20 (0.80, 1.79)
Adults aged 35–49 y
White, non-Hispanic (Ref)	1.00
Black, non-Hispanic	2.66 (2.28, 3.11)
Hispanic	0.87 (0.63, 1.19)
Adults aged 50–64 y
White, non-Hispanic (Ref)	1.00
Black, non-Hispanic	1.70 (1.44, 1.99)
Hispanic	0.70 (0.48, 1.02)
Adults aged 65–79 y
White, non-Hispanic (Ref)	1.00
Black, non-Hispanic	0.93 (0.74, 1.16)
Hispanic	1.15 (0.79, 1.68)
Adults aged ≥ 80 y
White, non-Hispanic (Ref)	1.00
Black, non-Hispanic	1.21 (0.93, 1.56)
Hispanic	0.66 (0.34, 1.27)
Percentage of census tract povertya
Adults aged 18–34 y
< 5% (Ref)	1.00
5%–9.9%	1.16 (0.82, 1.63)
10%–19.9%	1.29 (0.91, 1.81)
≥ 20%	2.06 (1.45, 2.91)
Adults aged 35–49 y
< 5% (Ref)	1.00
5%–9.9%	1.61 (1.31, 1.97)
10%–19.9%	2.13 (1.73, 2.62)
≥ 20%	5.69 (4.64, 6.99)
Adults aged 50–64 y
< 5% (Ref)	1.00
5%–9.9%	1.28 (1.08, 1.52)
10%–19.9%	1.74 (1.46, 2.09)
≥ 20%	3.37 (2.77, 4.10)
Adults aged 65–79 y
< 5% (Ref)	1.00
5%–9.9%	0.98 (0.83, 1.16)
10%–19.9%	1.35 (1.14, 1.61)
≥ 20%	1.51 (1.19, 1.92)
Adults aged ≥ 80 y
< 5% (Ref)	1.00
5%–9.9%	0.92 (0.78, 1.08)
10%–19.9%	0.91 (0.76, 1.09)
≥ 20%	0.77 (0.58, 1.02)

Note. ABCs = Active Bacterial Core surveillance; ARR = adjusted rate ratio; CI = confidence interval. The model included the main effects of age category, racial/ethnic category, percentage of census tract poverty, and surveillance site, and 2-way interactions between age and race/ethnicity and between age and percentage of census tract poverty.

^aPercentage of census tract poverty was defined according to the percentage of persons living below the federal poverty threshold per the 2000 US Census.²⁰