Table 1. Demographic and TAA variables stratified by residential distance to I-93.

Characteristic	Total (N=204)	≤50 m (N=32)	51–500 m (N=129)	>1,000 m (N=43)
Demographic variables
Age, mean (SD)	59.1 (12.4)	52.7 (10)a,b	60.5 (11.7)b	59.6 (14.8)
Female	66%	56%a	66%	72%
White	70%	58%a	66%c	93%
Smoking status
Current	22%	19%a	27%c	7%
Former	35%	16%a,b	36%b	47%
Never	37%	50%b	31%b,c	44%
Missing	6%	16%	6%	2%
Educational attainment
Less than high school diploma	26%	38%a	26%	16%
High school diploma	31%	31%a	38%	12%
Undergraduate school	28%	28%	25%	35%
Graduate school	15%	3%a,b	11%	37%
Annual Income
Less than $24,999	19%	12%	12%	14%
$25,000–$74,999	14%	19%b	44%b,c	25%
$75,000 or more	35%	28%	33%	42%
Do not know/refused	32%	41%a,b	11%c	19%
Employment
Working full time or part time	45%	66%a,b	36%b,c	58%
Retired, disabled or unemployed	52%	28%a,b	62%b,c	40%
Missing	3%	6%a,b	2%b,c	2%
Time-activity adjustment variables
Workday/weekday (mean hours (SD))
Inside home	17.14 (4.8)	15.07 (5.4)a	17.94 (4.2)c	16.34 (5.4)
Outside home	0.95 (2.53)	0.48 (1.16)	0.99 (2.14)	1.13 (3.78)
Work	3.95 (4.8)	7.66 (5.67)a,b	2.68 (4.07)b,c	4.96 (4.68)
Other	1.56 (2.53)	0.52 (0.96)a	2.02 (2.97)c	1.02 (1.47)
Highway	0.40 (0.97)	0.27 (0.48)	0.37 (0.71)	0.55 (1.58)
Non-workday/weekend (mean hours (SD))
Inside home	18.56 (4.6)	17.24 (4.6)	19.45 (3.5)c	17.09 (6.2)
Outside home	1.72 (3.5)	2.88 (5.33)	1.48 (2.72)	1.63 (4.01)
Work	1.46 (3.71)	1.86 (2.91)	0.63 (1.98)c	3.33 (6.12)
Other	1.89 (2.49)	1.42 (2.24)	2.13 (2.62)	1.58 (2.25)
Highway	0.37 (0.62)	0.6 (0.79)	0.32 (0.56)	0.37 (1.76)
Air conditioner (AC)
Yes	85%	81%	88%	81%
Open windows in winter
Yes	54%	53%a	59%c	40%
Missing	<1%	0%	<1%	0%
Open windows in summer
Yes	88%	88%	87%	93%
Missing	2%	3%	1%	2%

^aIndicates significant (P≤0.05) mean difference between the ≤50 m and >1,000 m distance group.

^bIndicates significant mean difference between the ≤50 m and 51–500 m distance group.

^cIndicates significant (P≤0.05) mean difference between the 51–500 m and >1,000 m distance group.