Table 2.

Adjusted mean differences (95% CIs) in PP and SBP (mmHg) per 10-ug/m³ increase in PM_2.5 (averaged for the prior 1–30 days) (n = 5,112), MESA, 2000–2002.

		PP			SBP
Model no.	Adjustment variables	Mean difference	95% CI	p-Value	Mean difference	95% CI	p-Value
1	Person-level covariatesa	1.04	0.25 to 1.84	0.010	0.66	−0.41 to 1.74	0.226
2	Person-level covariates,a weatherb	1.12	0.28 to 1.97	0.009	0.99	−0.15 to 2.13	0.089
2a	Person-level covariates,a weather,b gaseous co-pollutantsc	2.66	1.61 to 3.71	0.000	2.8	1.38 to 4.22	0.000
3	Person-level covariates,a study site	0.93	−0.04 to 1.90	0.060	0.86	−0.45 to 2.17	0.200
3a	Person-level covariates,a study site, weatherb	1.11	0.01 to 2.22	0.049	1.32	−0.18 to 2.82	0.085
3b	Person-level covariates,a study site, weather,b gaseous co-pollutantsc	1.34	0.10 to 2.59	0.035	1.52	−0.16 to 3.21	0.077

Adjusted relationships between blood pressure and temperature and SO₂ were fit using piecewise linear splines because they are positive for lower values and negative for higher values (breaks at 45ºF for temperature and 0.004 ppm for SO₂).

^aAge, sex, race/ethnicity, per capita income, education, BMI, diabetes status, cigarette smoking, exposure to ETS, alcohol use, physical activity, medications.

^bPrior 30-day mean for temperature and sea-level pressure.

^cPrior 30-day mean for NO₂, SO₂, and CO.