Table 3.

Estimates of summary linear ozone effect for all-cause mortality, assuming linear and threshold models and sensitivity analyses, using alternative temperature metrics (mean or maximum temperature) and adjusting for PM₁₀.

Area/model	Model	Spring	Summer	Fall	Winter
Urban
Mean temperature	O3 linear [% (95% CI)]a	0.13 (–0.14, 0.39)	0.65 (0.39, 0.91)	0.42 (–0.29, 1.12)	0.44 (0.13, 0.76)
Threshold [μg/m3 (95% CI)]	110 (83, 137)	64 (56, 73)	11 (0, 21)	33 (3, 64)
O3 linear > threshold [% (95% CI)]a	0.07 (–1.74, 1.89)	1.10 (0.71, 1.49)	0.39 (–0.33, 1.11)	0.40 (0.05, 0.75)
Maximum temperature	O3 linear [% (95% CI)]a	–0.06 (–0.35, 0.22)	0.21 (–0.10, 0.52)	0.42 (–0.29, 1.13)	0.45 (0.14, 0.75)
Threshold [μg/m3 (95% CI)]	NAb	97 (81, 112)	NAb	NAb
O3 linear > threshold [% (95% CI)]a	NAb	0.66 (–0.27, 1.58)	NAb	NAb
Mean temperature + PM10c	O3 linear [% (95% CI)]a	0.15 (–0.12, 0.42)	0.62 (0.35, 0.90)	0.05 (–0.54, 0.65)	0.13 (–0.21, 0.47)
Rural
Mean temperature	O3 linear [% (95% CI)]a	0.25 (–0.23, 0.72)	0.46 (–0.01, 0.92)	0.62 (0.08, 1.16)	0.39 (–0.13, 0.91)
Threshold [μg/m3 (95% CI)]	130, (97, 162)	79 (56, 101)	42 (6, 77)	76 (46, 106)
O3 linear > threshold [% (95% CI)]a	0.72 (–1.98, 3.42)	0.82 (0.22, 1.43)	0.49 (–0.36, 1.31)	1.02 (–0.82, 2.87)
Maximum temperature	O3 linear [% (95% CI)]a	0.11 (–0.44, 0.65)	0.18 (–0.32, 0.69)	0.58 (0.07, 1.10)	0.42 (–0.10, 0.94)
Threshold [μg/m3 (95% CI)]	NAb	136 (100, 172)	NAb	NAd
O3 linear > threshold [% (95% CI)]a	NAb	0.46 (–1.21, 2.14)	NAb	NAd
aRandom effect summary estimate percent increase in daily mortality per 10-μg/m3 increase in 8-hr maximum ozone concentrations on the current day and on the previous day. bNot appropriate because linear concentration–response relationship assumed. cModel includes natural cubic spline for PM10 average lag 0–1.