Table 2– Secondary analyses for air pollution exposure and risk of acute exacerbation

Secondary analysis	O₃	NO₂	PM₁₀	CO	SO₂
Within 15 km of TMS^#
Mean	1.67 (1.08–2.57)^§	1.47 (1.06–2.05)	0.97 (0.67–1.40)	1.29 (1.00–1.67)	0.97 (0.65–1.45)
Maximum	1.57 (1.14–2.16)^§	1.24 (0.96–1.59)	1.03 (0.67–1.57)	1.09 (0.76–1.56)	0.97 (0.72–1.31)
Adjusted for temperature and relative humidity^¶
Mean	1.43 (0.93–2.21)^ƒ	1.43 (1.00–2.06)	0.91 (0.60–1.37)	1.24 (0.83–1.83)	0.96 (0.65–1.41)
Maximum	1.60 (1.21–2.12)^ƒ	1.22 (0.91–1.63)	0.70 (0.36–1.35)	1.03 (0.65–1.65)	1.01 (0.73–1.39)
All acute exacerbations⁺
Mean	1.51 (1.06–2.15)^##	1.40 (1.06–1.86)	1.17 (0.84–1.63)	1.29 (1.03–1.60)	1.09 (0.80–1.49)
Maximum	1.43 (1.15–1.78)^##	1.27 (1.01–1.60)	1.22 (0.87–1.70)	1.18 (0.93–1.51)	1.08 (0.85–1.37)

Data are presented as hazard ratio (95% CI), where the hazard ratio is expressed per sd increase in measured exposure. O₃: ozone; NO₂: nitrogen dioxide; PM₁₀: particles with a 50% cut-off aerodynamic diameter of 10 µm; CO: carbon monoxide; SO₂: sulfur dioxide; TMS: Tele-Monitoring System. ^#: n=66; ^¶: n=51; ⁺: n=89; ^§: n=42; ^ƒ: n=33; ^##: n=55.