Table 5. Longitudinal models for spirometric variables and Socioeconomic status (SES), both genders taken together.

Variables	(1)	(2)	(3)	(4)
Ln FEV1 (mL)
Ln (Monthly family income) ¶	0.00296*	0.00127	0.00126	0.000725
Parents’ schooling (years)	0.00366***	-0.001	-0.00101	-0.000649
Gender	0.0443***	0.0480***	0.0481***	0.0486***
Age (years)	0.176***	-0.00906	-0.00791	-0.00385
Age2 (years2)	-0.00220***	0.00198***	0.00193***	0.00166***
Height (cm)		0.0128***	0.0127***	0.0128***
Weight (kg)		0.00396***	0.00396***	0.00392***
Secondhand smoke			-0.00169	-0.00239**
O3 δ ppb				-0.00102***
Constant	5.961***	5.591***	5.587***	5.634***
SD (residuals)	0.0786	0.0694	0.0759	0.0754
Observations	11,954	11,954	11,950	11,950
AIC §	-19753.24	-23462.42	-23452.74	-23588.63
Ln FVC (mL)
Ln (Monthly family income)	0.00379**	0.00215	0.00212	0.00175
Parents’ schooling (years)	0.00406***	-0.000441	-0.000452	-0.00023
Gender	0.0681***	0.0735***	0.0737***	0.0740***
Age (years)	0.153***	-0.0214***	-0.0187***	-0.0163***
Age2 (years2)	-0.00152***	0.00232***	0.00220***	0.00204***
Height (cm)		0.0113***	0.0113***	0.0113***
Weight (kg)		0.00513***	0.00513***	0.00511***
Secondhand smoke			-0.00428***	-0.00473***
O3 δ ppb				-0.000619***
Constant	6.226***	5.941***	5.934***	5.962***
SD (residuals)	0.0786	0.0694	0.0694	0.0692
Observations	11,961	11,961	11,957	11,957
AIC §	-21390.43	-25267.34	-25270	-25327.86

^¶Natural logarithm of income in 2002 U.S. dollars (USD)

^δPrevious 6 months of the daily O₃ 8-hour mean (parts per billion [ppb] 10 a.m. to 6 p.m.)

^§AIC: Akaike information criterion.

***p <0.01

**p <0.05

*p <0.1.