Table 1.
Characteristics of NSHAP study participants by the highest and lowest categories of roadway distance and urbanicity measures, respectively.a
| Characteristic | Proximity to roadway |
Urbanicity |
||||
|---|---|---|---|---|---|---|
| 0–49 m | ≥200 m | p-Value | 1st tertile (least urban) | 3rd tertile (most urban) | p-Value | |
| No. of participants | 1026 | 3724 | 2201 | 2227 | ||
| Age (year, mean ± SD) | 71.0 ± 7.8 | 70.7 ± 8.2 | 70.1 ± 8.0 | 71.1 ± 8.2 | ||
| Male (%) | 47.2 | 48.1 | 0.0198 | 48.8 | 46.2 | 0.0697 |
| Race (%) | ||||||
| White | 69.1 | 73.4 | <0.0001 | 83.0 | 55.3 | <0.0001 |
| Black | 18.7 | 13.8 | 10.5 | 23.3 | ||
| Hispanic non-black | 10.2 | 10.4 | 18.3 | 4.5 | ||
| Other | 2.0 | 2.4 | 3.1 | 2.0 | ||
| BMI (kg/m2, mean ± SD) | 29.5 ± 6.6 | 29.3 ± 6.0 | 29.3 ± 6.0 | 29.3 ± 6.1 | ||
| Current smoking (%) | 15.9 | 13.1 | 0.0417 | 13.8 | 15.0 | 0.2193 |
| Physically active (≥1 times per week %) | 64.2 | 66.9 | 0.1728 | 69.1 | 64.1 | 0.0009 |
| Socioeconomic status | ||||||
| Education attainment (%) | ||||||
| College degree or greater | 22.3 | 24.1 | 0.0015 | 23.9 | 20.5 | <0.0001 |
| High school or equivalent | 52.7 | 55.2 | 58.0 | 54.0 | ||
| Less than high school | 25.0 | 20.7 | 18.0 | 25.5 | ||
| Family income (% ≤$35,000) | 46.1 | 37.8 | <0.0001 | 36.4 | 45.1 | <0.0001 |
| Median household income ($ in thousands, mean ± SD)b | 50.2 ± 24.0 | 57.0 ± 27.3 | 55.5 ± 24.7 | 52.6 ± 24.7 | ||
| Diabetes (%) | 23.1 | 22.5 | 0.8980 | 22.0 | 23.4 | 0.5163 |
| Hypertension (%) | 62.2 | 58.6 | 0.0928 | 57.9 | 61.7 | 0.0286 |
| Stroke (%) | 9.1 | 8.9 | 0.5740 | 9.5 | 9.0 | 0.7426 |
| Diabetes (%) | 8.8 | 6.9 | 0.0435 | 6.7 | 7.8 | 0.2434 |
| Respiratory illness (%) | 17.7 | 15.4 | 0.0982 | 16.6 | 15.2 | 0.2504 |
| Lonely ≥80th percentile (%) | 26.5 | 23.9 | 0.0994 | 22.6 | 26.8 | 0.0043 |
| Social support (socializing ≥1 per month, %) | 44.6 | 48.3 | 0.0027 | 51.4 | 41.7 | <0.0001 |
| Much difficulty get-up-and-go (≥2 score) (%) | 24.5 | 21.2 | 0.0655 | 21.2 | 22.4 | 0.5913 |
| Perceived stress score (mean ± SD) | 2.9 ± 2.4 | 2.6 ± 2.3 | 2.6 ± 2.3 | 2.8 ± 2.3 | ||
| Anxiety score (mean ± SD) | 4.5 ± 3.6 | 4.2 ± 3.3 | 4.2 ±3.3 | 4.3 ±3.4 | ||
| Depressive score (mean ± SD) | 5.7 ± 5.3 | 5.1 ± 4.9 | 4.9 ± 4.7 | 5.7 ± 5.3 | ||
| Resided in MSA (%) | 85.7 | 86.0 | <0.0001 | 74.7 | 98.5 | <0.0001 |
| Temperature annual (C, mean ± SD) | 14.0 ± 4.0 | 14.8 ± 4.5 | 14.4 ± 4.2 | 14.8 ± 4.5 | ||
| PM2.5 annual concentration (μg/m3, mean ± SD) | 9.8 ±3.0 | 9.7 ± 2.9 | 8.6 ± 2.7 | 11.0 ±2.7 | ||
| Urbanicity (mean ± SD) | 48.7 ± 33.9 | 43.0 ± 31.9 | - | - | ||
| Roadway distance (mean ± SD) | - | - | 544.8 ± 394.0 | 222.1 ± 181.4 | ||
| Greenness (mean ± SD) | 0.48 ± 0.18 | 0.53 ± 0.16 | 0.58 ± 0.17 | 0.43 ± 0.14 | ||
Abbreviations: SD refers to standard deviation; BMI refers to body mass index; COPD refers to chronic obstructive pulmonary disease; CESD stands for the Center for Epidemiological Studies – Depression; HADS-A stands for the Hospital Anxiety and Depression Scale – anxiety subscale; NDVI refers to the normalized difference vegetation index; MSA refers to metropolitan statistical area; PM2.5 refers to particulate matter with aerodynamic diameter of 2.5 micro or less.
2261 participants were in both wave 1 and wave 2; 744 participants were in wave 1 only; 1113 were in wave 2 only.
Estimated for census tract of residence using data from the U.S. Census Bureau (2000).