Table 5.
RRs (95% CI) and P Values in Associations Between 10 μg/m3 Increments of PM2.5 Concentrations and PVC Counts After Excluding Segments With Large Numbers of PVCs
| Excluding segments with >60 PVCs | Excluding segments with >30 PVCs | |||
|---|---|---|---|---|
| RR (95% CI) | P value | RR (95% CI) | P value | |
| Lag 0, instantaneous | 0.992 (0.997, 1.007) | 0.30 | 0.991 (0.972, 1.011) | 0.38 |
| Lag 1, 0.5–1.0 h prior | 1.016 (1.006, 1.027) | 0.13 | 1.016 (1.005, 1.027) | <0.01 |
| Lag 2, 1.0–1.5 h prior | 1.024 (1.014, 1.034) | <0.01 | 1.025 (1.015, 1.035) | <0.01 |
| Lag 3, 1.5–2.0 h prior | 1.013 (1.002, 1.025) | 0.03 | 1.017 (1.005, 1.030) | <0.01 |
| Cumulative, within 2.0 h | 1.046 (1.002, 1.009) | 0.04 | 1.050 (1.000, 1.103) | 0.05 |
All models were adjusted for age, race, sex, body mass index percentile, temperature, and relative humidity. PM2.5 indicates fine particles with aerodynamic diameters ≤2.5 μm; PVC, premature ventricular contraction; and RR, rate ratio.