Table 2.

Demographic and socioeconomic variables predicting the number of decayed teeth among adults age 50 years and older 1988–2004 using negative binomial regression models (n=9113)

	Model 1		Model 2		Model 3		Model 4
Variable	IRR	p-value	IRR	p-value	IRR	p-value	IRR	p-value
Intercept	0.64 (0.53, 0.76)	<0.001	0.66 (0.51, 0.85)	<0.001	1.53 (1.04, 2.25)	0.005	2.85 (1.82, 4.46)	<0.001
Time	0.98 (0.96, 1.00)	0.011	0.98 (0.95, 1.00)	0.019	1.00 (0.97, 1.02)	0.623	0.99 (0.97, 1.01)	0.114
Age 65+			0.88 (0.70, 1.11)	0.139	0.77 (0.61, 0.96)	0.002	0.68 (0.52, 0.87)	<0.001
Female			0.68 (0.57, 0.82)	<0.001	0.65 (0.54, 0.78)	<0.001	0.62 (0.51, 0.75)	<0.001
Race/Ethnicity Black			2.55 (1.95, 3.33)	<0.001	2.03 (1.56, 2.64)	<0.001	1.81 (1.36, 2.41)	<0.001
Mexican-American			2.45 (1.63, 3.69)	<0.001	1.45 (0.98, 2.14)	0.014	1.27 (0.82, 1.95)	0.150
Other Race			1.67 (1.02, 2.72)	0.007	1.56 (0.92, 2.64)	0.028	1.32 (0.77, 2.26)	0.184
Years of Education					0.67 (0.60, 0.75)	<0.001	0.77 (0.69, 0.86)	<0.001
Poverty Quartile							0.65 (0.57, 0.74)	<0.001

IRR=Incidence rate ratio

Confidence limits based on 99% confidence intervals