Table 5

Pooled rate ratios (RRs) and 95 % confidence intervals (95% CIs) for the associations of daily air pollution levels with hospitalisation for first acute myocardial infarction by age and fatality in the three cities with hospital discharge registers

Pollutant	Lag	Age <75		Age ⩾75
Pollutant	Lag	Non-fatal RR* (95 % CI)	Fatal RR (95 % CI)	Non-fatal RR (95 % CI)	Fatal RR (95 % CI)
*Rate ratios calculated for a change of 10 000 particles/cm³ in PNC, 10 μg/m³ in PM₁₀, 0.2 mg/m³ in CO, and 8 μg/m³ in NO₂.
†City-specific results heterogeneous (p<0.1), random effects model used for pooling.
CO	0	1.001 (0.995–1.008)	1.027 (1.006–1.048)	1.015 (1.004–1.026)	1.009 (0.992–1.026)
	1	1.000 (0.994–1.007)	1.021 (1.000–1.042)	1.006 (0.995–1.017)	1.001 (0.985–1.018)
	2	1.004 (0.998–1.011)	1.018 (0.997–1.039)	0.995 (0.983–1.006)	1.006 (0.990–1.023)
	3	0.999† (0.992–1.006)	1.015 (0.994–1.037)	0.998 (0.987–1.009)	1.000 (0.983–1.017)
NO₂	0	0.995 (0.982–1.008)	1.004 (0.971–1.039)	1.011 (0.993–1.029)	1.009 (0.984–1.034
	1	1.003† (0.979–1.028)	1.032 (0.998–1.066)	0.997 (0.979–1.015)	0.994 (0.969–1.019)
	2	1.015 (1.002–1.028)	1.021 (0.987–1.057)	0.995 (0.977–1.013)	0.997 (0.972–1.022
	3	1.009† (0.988–1.031)	1.019 (0.985–1.053)	1.010 (0.992–1.028)	0.985 (0.960–1.011)
PNC	0	1.001 (0.985–1.017)	1.050 (1.000–1.101)	1.032 (1.008–1.056)	1.016 (0.978–1.055
	1	0.999† (0.984–1.014)	1.058 (1.012–1.107)	1.009 (0.985–1.032)	1.001 (0.966–1.038)
	2	1.010 (0.996–1.025)	1.023 (0.977–1.071)	0.989 (0.966–1.013)	1.005 (0.969–1.041
	3	1.029† (0.976–1.084)	1.025 (0.979–1.073)	1.009† (0.969–1.051)	0.984 (0.948–1.021)
PM₁₀	0	0.997 (0.986–1.008)	1.031 (1.000–1.064)	1.012 (0.995–1.029)	1.009 (0.985–1.034
	1	0.997 (0.986–1.008)	1.026 (0.994–1.058)	1.000 (0.983–1.017)	0.998 (0.974–1.023
	2	1.005 (0.994–1.016)	0.999 (0.967–1.032)	0.999 (0.982–1.017	1.003 (0.978–1.028)
	3	0.994 (0.983–1.005)	1.022 (0.991–1.055)	1.001 (0.984–1.018)	1.018† (1.063–0.975)