Table 3.

Model 1: Gaussian multilevel generalized additive model of cognitive function score.

Parametric terms:
parameter	estimate	std. error	t-value
Intercept	0.315	0.125	2.52
Age at baseline	−0.094	0.001	−76.66
Years from baseline test	−0.075	0.002	−34.05
White	0.962	0.031	31.33
Male	−0.344	0.023	−15.24
Education: college degree (ref.)	-	-	-
Education: high school degree	−0.900	0.024	−37.08
Education: no formal degree	−1.743	0.041	−42.16
Tract, proportion owner occupied housing	0.192	0.074	2.60
Tract, proportion Black	−0.152	0.049	−3.09
Tract, proportion below poverty line	−0.340	0.112	−3.04
Population density (logged)	0.035	0.012	3.04
Random terms:
parameter	std. deviation
Person-specific intercepts	1.263
Person-specific time slopes	0.127
Tract-specific intercepts	0.229
County-specific intercepts	0.165
Smooth terms:
parameter	EDF	p-value
Tract, recreation center density	0.795	0.031
Tract, social organization density	2.240	<0.001
Tract, religious organization density	0.000	1.000
Tract, fast-food and coffee density	0.913	0.002
Tract, senior services density	0.000	1.000
Tract, educational organization density	0.623	0.103
Tract, arts organization density	0.813	0.025
Tract, museum density	0.800	0.026
Tract, library density	0.000	1.000
Tract, polluting site density	0.000	1.000
Tract, parks density	0.000	1.000
Tract, highway density	0.933	0.002
Tract, grocery store density	0.025	0.311

Note: EDF denotes “effective degrees of freedom” and summarizes the number of parameters associated with each smooth term. Ref. indicates “reference category.”