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Table 3 Pooled hazard ratios, 95% confidence intervals and heterogeneity measures from distributed lag models

From: Air pollution in the week prior to delivery and preterm birth in 24 Canadian cities: a time to event analysis

Lag Hazard Ratioa 95% confidence intervala p I2 Q p(Q)
0 1.032 1.017 1.048 <.0001 12.83% 26.3845 0.2831
1 1.010 1.001 1.020 0.0327 26.81% 31.4232 0.1127
2 0.994 0.984 1.005 0.2897 38.81% 37.5859 0.0282
3 0.985 0.973 0.997 0.0171 33.68% 34.6821 0.0559
4 0.987 0.978 0.996 0.0066 23.55% 30.0833 0.147
5 1.000 0.993 1.007 0.9832 0.00% 18.9691 0.703
6 1.019 1.006 1.032 0.005 0.00% 22.7601 0.4749
0–1 1.032 1.016 1.049 <.0001 16.81% 27.649 0.2293
0–2 1.042 1.016 1.068 0.0012 23.37% 30.0158 0.1489
0–3 1.036 1.005 1.067 0.0209 29.10% 32.4378 0.0914
0–4 1.022 0.987 1.057 0.227 33.94% 34.8155 0.0543
0–5 1.009 0.971 1.049 0.6396 34.61% 35.1717 0.05
0–6 1.006 0.971 1.042 0.7587 20.63% 28.9787 0.181
  1. aPer 13.3 ppb O3 (interquartile range)