Table 1 Characteristics of the study population stratified by categories of distance to the highway
Within 50 m | 50 m-150 m | 150-250 m | 250-450 m | >1000 m | |
|---|---|---|---|---|---|
(N = 30) | (N = 58) | (N = 65) | (N = 54) | (N = 53) | |
Demographic variables | |||||
Age, mean (SD) | 56.1 (11) | 55.9 (11.36)# | 61.9 (10.6)*# | 58.6 (10.97) | 56.7 (13.65) |
BMI | 31.9 (7.42)*# | 27.7 (5.75)# | 31.9 (7.85)*# | 29.5 (7.65) | 28.2 (7.58) |
Female | 57% | 52% | 58% | 63% | 68% |
Born in USA | |||||
Yes | 53% | 71% | 72% | 57% | 68% |
Missing | 10% | 1% | 3% | 2% | 4% |
Race | |||||
White | 67% | 70% | 65% | 63% | 64% |
Non-white | 30% | 28% | 34% | 37% | 36% |
Missing | 3% | 2% | 1% | 0% | 0% |
Annual household income | |||||
Less than $24,999 | 27%# | 26%# | 61%*# | 35%# | 28% |
$25,000-$74,999 | 43%# | 40%# | 25%# | 31% | 25% |
$75,000 or more | 10% | 22%# | 8%*# | 22%# | 38% |
Don’t know/ refused | 20%# | 12% | 6%# | 11% | 9% |
Terminal degree | |||||
Less than high school | 27% | 14% | 31% | 24% | 13% |
High school | 46%*# | 33% | 26%# | 37% | 21% |
Undergraduate | 27% | 39%*# | 25%# | 20% | 32% |
Graduate | 0% | 14% | 18% | 19% | 34% |
Employment | |||||
Working full or part time | 53%# | 45%# | 28%*# | 43% | 53% |
Retired, disabled, unemployed | 37%# | 52%# | 69%*# | 57% | 45% |
Missing | 10% | 3% | 3% | 0% | 2% |
Study area | |||||
Somerville | 67%# | 38%*# | 53% | 69%*# | 49% |
Exposure variables | |||||
Workday time spent inside home (hrs) | 14.6 (5.41) | 17.1 (4.62) | 17.4 (4.16) | 16.7 (5.85) | 16.8 (4.39) |
Non-workday time spent inside home (hrs) | 17.2 (5.37) | 18.5 (4.23) | 19.5 (4.12) | 18.7 (5.27) | 17.7 (5.20) |
Previous week combustion exposure score | 3.1 (2.35) | 3.9 (1.92) | 3.8 (2.03) | 3.9 (2.38) | 3.2 (1.98) |
Job combustion score | 3.27 (1.62) | 3.21 (1.64) | 3.70 (1.65) | 3.20 (1.69) | 3.17 (1.61) |
Open windows in winter | |||||
Yes | 59% | 59% | 63% | 52% | 49% |
Missing | 3% | 3% | 2% | 0% | 0% |
Open windows in summer | |||||
Yes | 96% | 96% | 91% | 91% | 94% |
Missing | 3% | 2% | 5% | 0 | 2% |
Travel on highway | |||||
Yes | 17%# | 4%*# | 15%# | 17%# | 11% |
Missing | 3% | 2% | 0% | 0% | 0% |
Health & medications | |||||
Statin medication | 13% | 33% | 21% | 33% | 23% |
Previous heart attack | 3% | 5% | 9% | 5% | 6% |
Diabetes | 13% | 14% | 15% | 15% | 15% |