Exposure to Greenness and Mortality in a Nationwide Prospective Cohort Study of Women

http://dx.doi.org/10.1289/ehp.1510363



Table 1. Age-adjusted Nurses’ Health Study participant characteristics by quintiles of cumulative average Normalized Difference Vegetation Index within 250-m buffers from 2000 to 2008 (n = 108,630).
Characteristic Total Greenness quintile 1 Greenness quintile 2 Greenness quintile 3 Greenness quintile 4 Greenness quintile 5
Abbreviations: BMI, body mass index; MET, metabolic equivalent of task; NDVI, Normalized Difference Vegetation Index; PM2.5, particulate matter < 2.5 μm in aerodynamic diameter; RN, registered nurse.
aValue is not age-adjusted.
Cumulative average NDVI (250-m buffer) (mean ± SD) 0.47 ± 0.12 0.29 ± 0.08 0.42 ± 0.03 0.48 ± 0.03 0.54 ± 0.03 0.62 ± 0.05
Age (years)a (mean ± SD) 68.98 ± 7.29 69.89 ± 7.26 69.42 ± 7.32 68.94 ± 7.30 68.49 ± 7.24 68.16 ± 7.18
White non-Hispanic (%) 94 90 94 94 95 95
BMI (Mean ± SD) 25.83 ± 7.35 25.33 ± 8.26 25.91 ± 7.43 26.08 ± 7.18 25.98 ± 7.08 25.82 ± 6.79
Weight status (%)
Normal weight (BMI 18.5–24.9) 39 38 38 38 39 41
Overweight (BMI 25–29.9) 33 32 33 33 33 33
Obese (BMI > 30) 23 23 23 24 23 21
Missing BMI 6 8 6 5 5 5
Total physical activity, MET hrs/week (%)
< 3 23 23 23 23 22 21
3 to < 9 21 20 21 22 21 20
9 to < 18 18 18 19 18 19 19
18 to < 27 11 11 11 11 11 12
≥ 27 19 18 19 19 19 21
Missing 8 11 8 7 7 7
Smoking status (%)
Never smoker 44 44 45 45 44 44
Former smoker 45 45 45 45 46 47
Current smoker 10 11 11 10 10 10
Have RN degree (%) 73 69 73 74 74 74
Married (%) 64 58 63 65 66 68
Husband’s highest education (%)
< High school 4 4 4 4 4 3
High school graduate 26 25 27 27 26 24
> High school education 35 32 33 34 36 41
Missing or not married 35 39 35 34 34 32
Census 2000–tract median income (mean ± SD, USD) 63,000 ± 24,000 57,000 ± 22,000 60,000 ± 22,000 62,000 ± 22,000 66,000 ± 24,000 72,000 ± 29,000
Census 2000–tract median home value (mean ± SD, USD) 170,000 ± 125,000 175,000 ± 138,000 159,000 ± 121,000 156,000 ± 115,000 167,000 ± 113,000 194,000 ± 133,000
12-month average PM2.5 (μg/m3) (mean ± SD) 12.03 ± 2.80 12.51 ± 3.74 12.23 ± 2.79 12.05 ± 2.45 11.88 ± 2.28 11.47 ± 2.38
Census-tract urbanicity (%)
Metropolitan (urban area ≥ 50,000 people) 84 86 83 83 84 83
Micropolitan (urban cluster of 10,000–49,999) 10 9 10 10 9 10
Small town or rural (urban cluster of < 10,000) 7 5 7 7 6 7
Region (%)
Northeast 50 35 42 52 63 56
Midwest 17 15 24 22 15 8
West 14 34 16 8 5 7
South 19 16 18 17 17 28
Moved during follow-up (%) 32 33 30 30 30 35
Depression (physician-diagnosed or antidepressant use) (%) 12 11 12 12 11 11
Social engagement (participation in groups > 1 hr per week) (%) 68 67 69 69 68 69