Table 2.
Single-pollutant hazard ratios (HR) and 95% confidence intervals (CI), per increase of 10 μg/m3 for the continuous variables, between air pollution exposure to BS, SO2, NO2 (contemporaneous 1991 estimates) and CVD mortality (1989–2015). M1: model adjusted only for cohort to which the participant belongs. M2: M1 + age, gender. M3: M2 + type of employment, 1991 Carstairs index. M4 (fully-adjusted model): M3 + diabetes, smoking status, ethnicity, baseline CVD.
| # Events/n (%) | M1 | M2 | M3 | M4 | |
|---|---|---|---|---|---|
| Continuous | |||||
| NO2 | 610/7529 (8.1%) | 1.03 (0.90 to 1.18) | 1.06 (0.91 to 1.23) | 0.94 (0.79 to 1.12) | 0.97 (0.81 to 1.16) |
| SO2 | 610/7529 (8.1%) | 1.27 (1.13 to 1.42) | 1.19 (1.05 to 1.34) | 1.07 (0.94 to 1.23) | 1.05 (0.91 to 1.22) |
| BS | 610/7529 (8.1%) | 1.66 (1.19 to 2.32) | 1.44 (1.02 to 2.04) | 1.16 (0.81 to 1.65) | 1.11 (0.76 to 1.61) |
| Quartiles | |||||
| NO2-q1:[18.2–31.4] | 62/1974 (3.1%) | 1 | 1 | 1 | 1 |
| NO2-q2:(31.4–44.4] | 142/1909 (7.4%) | 0.99 (0.7 to 1.39) | 0.93 (0.65 to 1.33) | 0.76 (0.51 to 1.12) | 0.75 (0.50 to 1.11) |
| NO2-q3:(44.4–46.6] | 224/1868 (12.0%) | 1.24 (0.86 to 1.79) | 1.10 (0.75 to 1.62) | 0.86 (0.56 to 1.32) | 0.86 (0.56 to 1.32) |
| NO2-q4:(46.6–67.9) | 182/1778 (10.2%) | 1.07 (0.74 to 1.55) | 1.05 (0.71 to 1.56) | 0.81 (0.53 to 1.26) | 0.87 (0.56 to 1.34) |
| SO2-q1:[6.5–29.2] | 60/1974 (3.0%) | 1 | 1 | 1 | 1 |
| SO2-q2:(29.2–33.0] | 113/1820 (6.2%) | 1.02 (0.73 to 1.44) | 1.04 (0.73 to 1.47) | 0.82 (0.55 to 1.20) | 0.85 (0.58 to 1.25) |
| SO2-q3:(33.0–41.2] | 213/2069 (10.3%) | 1.52 (1.08 to 2.12) | 1.35 (0.95 to 1.91) | 1.10 (0.76 to 1.61) | 1.08 (0.74 to 1.57) |
| SO2-q4:(41.2–57.3) | 224/1666 (13.4%) | 1.66 (1.17 to 2.34) | 1.43 (1.00 to 2.05) | 1.01 (0.67 to 1.51) | 1.01 (0.67 to 1.51) |
| BS-q1:[0.08–11.2] | 82/2000 (4.1%) | 1 | 1 | 1 | 1 |
| BS-q2:(11.2–12.5] | 151/1776 (8.6%) | 0.96 (0.71 to 1.29) | 0.94 (0.69 to 1.27) | 0.92 (0.68 to 1.26) | 0.98 (0.71 to 1.34) |
| BS-q3:(12.5–14.9] | 217/2182 (9.9%) | 1.27 (0.96 to 1.69) | 1.15 (0.86 to 1.53) | 1.01 (0.75 to 1.36) | 1.02 (0.75 to 1.39) |
| BS-q4:(14.9–27.2] | 160/1581 (10.1%) | 1.54 (1.16 to 2.06) | 1.42 (1.05 to 1.90) | 1.23 (0.91 to 1.66) | 1.24 (0.91 to 1.69) |