Table 5.
Association between PM2.5 exposure and stroke incidence in subsets of the 11 cohorts under study: results of the threshold analyses.
| Threshold (μg/m3) | Cohorts (n) | Participants (n) | HR (95% CI) |
|---|---|---|---|
| Cohorts with PM2.5 concentrations for the respective threshold | |||
| < 15 | 7a | 72,769 | 1.24 (0.98, 1.58) |
| < 20 | 9b | 84,496 | 1.29 (1.00, 1.68) |
| < 25 | 9b | 86,812 | 1.29 (0.84, 1.98)* |
| Cohorts with PM2.5 concentrations available for all thresholds | |||
| Full range of exposure | 7a | 73,446 | 1.33 (1.01, 1.77) |
| < 15 | 7a | 72,769 | 1.24 (0.98, 1.58) |
| < 20 | 7a | 73,446 | 1.33 (1.01, 1.77) |
| < 25 | 7a | 73,446 | 1.33 (1.01, 1.77) |
| aAll except HNR, EPIC-Turin, SIDRIA-Turin and SIDRIA-Rome. bAll except EPIC-Turin and SIDRIA-Turin. *pheterogeneity < 0.05, as indicated by Cochran’s Q or I2 > 50%. | |||