. 2012 Jul 19;120(10):1411–1417. doi: 10.1289/ehp.1104108

Table 2.

Results from analyses that assumed linear, linear-threshold, and spline models for all-cause mortality.

Area	Linear model			Threshold model
	Linear model			Ozone range (μg/m³)	Ozone threshold [μg/m³ (95% CI)]	Percent (95% CI)^c	ΔAIC^d	Linearity p-value^e	ΔAIC^d
	Percent (95% CI)^a	AI^b		Ozone range (μg/m³)	Ozone threshold [μg/m³ (95% CI)]	Percent (95% CI)^c	ΔAIC^d	Linearity p-value^e	ΔAIC^d
Urban
Liverpool	0.72 (0.19, 1.26)	17,553	3.0–142.0	6 (3, 122)	0.73 (0.19, 1.27)	5.9	0.08	–0.9
London	0.38 (0.22, 0.55)	39,427	1.7–178.2	65 (58, 83)	1.33 (0.80, 1.86)	–23.8	0.00	–20.6
Manchester	0.68 (0.28, 1.07)	25,055	1.6–148	6 (1, 23)	0.68 (0.29, 1.07)	6.0	0.06	–1.5
Tyneside	0.50 (–0.02, 1.02)	21,749	2.0–154.5	2 (2, 155)	0.50 (–0.02, 1.02)	6.0	0.51	3.7
West Midlands	0.55 (0.30, 0.80)	34,444	2.4–173.2	2 (2, 27)	0.55 (0.30, 0.80)	6.0	0.11	–0.1
Summary estimate	0.48 (0.35, 0.60)
Rural
Aston Hill	0.42 (–0.19, 1.03)	23,626	6–209.5	88 (6, 134)	1.31 (0.22, 2.41)	2.3	0.29	2.2
Harwell	0.54 (0.13, 0.94)	26,083	2–193	12 (2, 119)	0.55 (0.14, 0.96)	5.8	0.17	0.9
High Muffles	0.29 (–0.36, 0.94)	23,384	2.5–185.5	181 (2, 186)	NAf	5.5	0.09	–0.5
Ladybower	0.86 (0.41, 1.31)	25,971	3–187.5	3 (3, 66)	0.86 (0.41, 1.31)	6.0	0.85	5.2
Yarner Wood	0.59 (0.04, 1.15)	24,074	2.5–220	2 (2, 219)	0.59 (0.04, 1.15)	6.0	0.06	–1.4
Summary estimate	0.58 (0.36, 0.81)
aPercent increase in daily all-cause mortality per 10-µg/m3 increase in maximum 8-hr ozone concentrations on the current day and previous day. bAIC for models including linear term for ozone. cPercent increase in daily all-cause mortality per 10-µg/m3 increase above threshold in maximum 8-hr ozone concentrations on the current day and previous day. dChange in AIC from linear model (negative indicates better fit than linear). ep-Value test for departure from linearity. fInsufficient data to estimate coefficient above threshold.