Table 1. Parameter estimates (Est), standard error (SE), p-value, AIC and BIC values for the ZIP-W ${}^b$, ZIP-W ${}^c$, ZIP-O ${}^b$ and ZIP-O ${}^c$ models for modeling the number of hospital admissions for respiratory causes over 315 municipalities in Turin province (Italy) in 2004.

	ZIP-W ${}^b$			ZIP-W ${}^c$			ZIP-O ${}^b$			ZIP-O ${}^c$
	Est	SE	p-value	Est	SE	p-value	Est	SE	p-value	Est	SE	p-value
	Binary component
${\mathrm{\text{β}}}_0$(intercept)	4.24	0.52	0.00	0.03	0.12	0.81	−3.31	0.20	0.00	−0.11	0.13	0.39
${\xi }_1$ $(\log (E\left)\right)$	−2.27	0.27	0.00
	Count component
${\alpha }_0$ (intercept)	1.04	0.13	0.00	0.79	0.14	0.00	−0.55	0.15	0.00	0.21	0.13	0.10
${\alpha }_1$ $\left({\text{NO}}_2^{\left(1\right)}\right)$	0.24	0.12	0.04	0.34	0.12	0.00	0.85	0.17	0.00	0.36	0.14	0.01
${\alpha }_2$ $\left({\text{NO}}_2^{\left(2\right)}\right)$	0.43	0.12	0.00	0.48	0.13	0.00	0.91	0.17	0.00	0.26	0.14	0.07
${\xi }_2$ $(\log (E\left)\right)$	0.73	0.04	0.00	0.78	0.04	0.00
${\sigma }_b^2$	0.15	0.38	0.00	0.15	0.39	0.00	0.48	0.69	0.00	0.23	0.48	0.00
	Model fit
AIC	1358.04			1560.22			1856.33			1585.32
BIC	1384.30			1582.74			1875.10			1604.08