Table 4.

National-average percentage differences (posterior means and 95% posterior intervals) in daily total mortality per $10{-\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$ increase in ozone concentration in 272 Chinese cities, classified by age, sex and educational attainment.

Characteristic	Level	Estimates	p-Valuea
Age	5–64 y	0.13 ($-0.23$, 0.48)	0.12
	65–74 y	0.19 (0.03, 0.34)
	$\ge 75\mathrm{y}$	0.42 (0.21, 0.64)
Sex	Male	0.26 (0.13, 0.39)	0.75
	Female	0.21 (0.05, 0.36)
Education	$\le 9\mathrm{y}$	0.25 (0.14, 0.37)	0.41
	$>9\mathrm{y}$	0.06 ($-0.30$, 0.43)

Note: Estimates were generated using over-dispersed generalized linear models and polynomial distributed lag model for cumulative exposures over the same day and 3 days prior, adjusted for calendar day [natural cubic spline with 7 degrees of freedom (df)], day of the week, temperature (cross-basis function for temperature lagged for 0–13 days from distributed lag nonlinear model), and humidity (lag 0, natural smooth function, 3 df) to estimate city-specific associations that were combined using hierarchical Bayesian models.

^aThe p-values were calculated by performing a likelihood ratio test between the simple meta-analysis model (overall estimates) and a separate meta-regression model with a categorical variable (age, sex, or education).