Concentration-Response Relationship between PM_2.5 and Daily Respiratory Deaths in China: A Systematic Review and Metaregression Analysis of Time-Series Studies

Table 2

Pooled risk estimates (percent increase in respiratory mortality [RM] per 10 g/m³ PM_2.5).

Subgroup	% increase in RM (95% CI)	I^2
Single-day lags
All	0.30 (0.10, 0.50)	84.1%
All (trim-and-fill)	0.12 (−0.06, 0.31)	47.8
Northern cities	0.24 (0.02, 0.46)	87.5%
Southern cities	0.46 (0.16, 0.76)	0.2%
Multiday lags
All	0.69 (0.55, 0.83)	0.0%
All (trim-and-fill)	0.66 (0.52, 0.79)	8.6
Northern cities	0.64 (0.49, 0.79)	0.0%
Southern cities	0.94 (0.60, 1.28)	0.0%

-effects model was used. -effects model was used.   Q.