Table 7.

  Results from random-effects meta-analyses for adjusted association between incidence of coronary events and exposure to PM₁₀ and PM_2.5 below various threshold values. Figures are pooled hazard ratios (95% CI) for 10 µg/m³ PM₁₀ and 5 µg/m³ PM_2.5, I² statistic, and P value for heterogeneity

Exposure and threshold	Cohorts with exposure data available for respective threshold						Cohorts with exposure data available for all thresholds
	No of cohorts	No of participants	HR* (95% CI)	I2	P value		No of cohorts	No of participants	HR* (95% CI)	I2	P value
PM10 (µg/m3):
Full range of exposure	—	—	—	—	—		7†	74 166	1.15 (1.02 to 1.30)	0	0.92
<20	7†	64 363	1.20 (1.01 to 1.41)	0	0.91		7†	64 363	1.20 (1.01 to 1.41)	0	0.91
<30	8‡	77 997	1.12 (0.98 to 1.27)	0	0.94		7†	74 019	1.12 (0.98 to 1.27)	0	0.91
<40	9§	86 222	1.12 (1.00 to 1.27)	0	0.48		7†	74 166	1.15 (1.02 to 1.30)	0	0.92
PM2.5 (µg/m3):
Full range of exposure	—	—	—	—	—		7†	74 166	1.23 (1.04 to 1.46)	0	0.57
<15	7†	73 420	1.19 (1.00 to 1.42)	0	0.74		7†	73 420	1.19 (1.00 to 1.42)	0	0.74
<20	9§	85 216	1.17 (0.91 to 1.50)	30	0.18		7†	74 166	1.23 (1.04 to 1.46)	0	0.57
<25	9§	87 532	1.18 (1.01 to 1.39)	0	0.56		7†	74 166	1.23 (1.04 to 1.46)	0	0.57

*Adjusted for age (time variable), year of enrolment, sex, marital status, education, occupation, smoking status, smoking duration, smoking intensity. and socioeconomic area level indicators

†All cohorts except Heinz Nixdorf Recall Study, EPIC-Turin, SIDRIA-Turin and SIDRIA-Rome.

‡All cohorts except EPIC-Turin, SIDRIA-Turin and SIDRIA-Rome.

§All cohorts except EPIC-Turin and SIDRIA-Turin.