Table 1.

Crude and multivariate adjusted effects of personal PM_2.5 exposure on BP by age.

Crude effectsa			Adjusted effectsb
Age (years)	n	Difference (mm Hg) (95% CI)	p-Value	Difference (mm Hg) (95% CI)	p-Value
SBP
25–50		142		1.6 (0.4 to 2.8)		0.008		0.7 (–0.8 to 2.1)		0.35
> 50		138		4.1 (1.7 to 6.5)		0.001		4.1 (1.5 to 6.6)		0.002
All		280		2.7 (1.4 to 4.1)		< 0.001		2.2 (0.8 to 3.7)		0.003
DBP
25–50		142		0.1 (–1.1 to 1.3)		0.88		–0.6 (–1.7 to 0.5)		0.25
> 50		138		1.2 (–0.1 to 2.4)		0.06		1.8 (0.4 to 3.2)		0.01
All		280		0.0 (–0.8 to 0.8)		0.98		0.5 (–0.4 to 1.3)		0.31
The effect is the estimated difference in BP associated with a 1-unit increase in the log of PM2.5. aResults are from univariate mixed-effects models. bAdjusted for age, waist circumference, physical activity, SES, salt intake, day of the week, time of day, and average ambient temperature, with all variables modeled as continuous except day of the week; results are from multivariate mixed-effects models.