Table 2.
Linear regression estimates for systolic blood pressure regressed on the interaction among neighborhood, stress, and 24-hour averaged PM2.5 exposure
| 24-hour average PM2.5 exposure, number of days prior to exam | ||||||
|---|---|---|---|---|---|---|
| 2 days prior | 3 days prior | 4 days prior | ||||
| --1-- | --2-- | --1-- | --2-- | --1-- | --2-- | |
| Neighborhood | ||||||
| Southwest | ref | ref | ||||
| East | −3.90 (−9.05,1.26) | −4.71 (−9.87,0.45) | −4.14 (−9.76,1.49) | −3.58 (−8.96,1.80) | −4.17 (−10.13,1.79) | −4.96 (−11.29,1.37) |
| Northwest | −4.51* (−8.76,−0.25) | −1.57 (−5.52,2.39) | −4.20 (−9.18,0.78) | −1.58 (−6.10,2.94) | −5.54* (−11.00,−0.08) | −2.36 (−7.88,3.17) |
| PM2.5 | 3.06* (0.00,6.12) | 2.94 (−0.85,6.72) | 1.18 (−1.21,3.57) | 1.69 (−1.31,4.70) | 3.72 (−0.29,7.73) | 5.84* (0.45,11.24) |
| Stress level | ||||||
| Low stress | ref | ref | ref | ref | ref | ref |
| High stress | 0.37 (−3.28,4.01) | 3.76 (−2.90,10.42) | 0.94 (−2.65,4.53) | 6.67* (1.23,12. 10) | 0.43 (−3.26,4.12) | 9.79*** (4.68,14.89) |
| NeighborhoodXstress | ||||||
| SouthwestXstress | ref | ref | ref | |||
| EastXstress | −0.78 (−9.62,8.06) | −4.53 (−11.75,2.68) | −7.21 (−15.03,0.61) | |||
| NorthwestXstress | −8.76* (−16.16,−1.36) | −11.64*** (−18.18,−5.11) | −16.41** (−25.95,−6.86) | |||
| NeighborhoodXPM2.5 | ||||||
| SouthwestXPM2.5 | ref | ref | ref | |||
| EastXPM2.5 | 4.33 (−4.89,1.355) | 0.11 (−4.86,5.08) | −4.39 (−13.45,4.67) | |||
| NorthwestXPM2.5 | −4.23 (−14.68,6.22) | −6.08 (−16.24,4.09) | −8.01 (−19.29,3.27) | |||
| StressXPM2.5 | ||||||
| Low stressXPM2.5 | ref | ref | ref | |||
| High stressXPM2.5 | 6.11 (−2.41,14.63) | 7.16* (0.21,14. 11) | 14.85*** (0.74,2.23) | |||
| NeighborhoodXstressXPM2.5 | ||||||
| SouthwestXstressXPM2.5 | ||||||
| EastXstressXPM2.5 | −12.22 (−26.45,2.01) | −7.83 (−18.02,2.36) | −6.94 (−18.48,4.60) | |||
| NorthwestXstressXPM2.5 | −11.20 (−29.03,6.63) | −8.33 (−22.49,5.83) | −11.57 (−34.94,11.81) | |||
|
| ||||||
| Southwest neighborhood | ||||||
| Low stress | 2.94 (−0.85,6.72) | 1.69 (−1.31,4.70) | 5.84* (0.45,11.24) | |||
| High stress | 9.05** (3.29,14. 81) | 8.86** (3.20,14. 51) | 20.69*** (14.47,26. 92) | |||
| East neighborhood | ||||||
| Low stress | 7.26 (−1.01,15.53) | 1.80 (−2.03,5.63) | 1.45 (−5.20,8.10) | |||
| High stress | 1.16 (−7.91,10.22) | 1.14 (−5.12,7.39) | 9.36 (−1.97,20.68) | |||
| Northwest neighborhood | ||||||
| Low stress | −1.29 (−11.27,8.68) | −4.39 (−14.10,5.33) | −2.17 (−12.27,7.94) | |||
| High stress | −6.38 (−19.26,6.50) | −5.55 (−15.49,4.39) | 1.12 (−13.00,15.23) | |||
Results reported in the upper panel are regression coefficients (95% confidence intervals) for PM2.5, stress, and PM2.5-by-stress interaction terms. Results reported in the lower panel are post-estimation coefficients (95% confidence intervals) for the association between PM2.5 and systolic blood pressure at low (lower three quartiles of the stress distribution) and high (high quartile of the stress distribution) variable. PM2.5coefficients are interpreted as change in systolic blood pressure per 10 μg/m3 increase in PM2.5. All estimates are adjusted for: age, sex, race, education, and poverty income ratio. PM2.5 was mean-centered before interaction.
p<0.05;
p<0.01;
p<0.001 for difference from zero.