Table 1.
Characteristics of the study population in the Normative Aging Study (2000 to 2016)
| Demographic Characteristics | At first visit (2000 to 2013) (N = 456) | All visits (2000 to 2016) (N = 648) |
|---|---|---|
| Age, Mean (SD) | 75.0 (6.70) | 76.0 (6.68) |
| Body mass index (kg/m2), Mean (SD) | 27.7 (4.19) | 27.7 (4.27) |
| Years of education, Mean (SD) | 15.1 (3.00) | 15.0 (3.00) |
| Baseline annual income, thousands of 1965 $US, Mean (SD) | 8.61 (3.77) | 8.64 (3.78) |
| Smoking | ||
| Never, N (%) | 128 (28) | 190 (29) |
| Current, N (%) | 14 (3) | 21 (3) |
| Former, N (%) | 314 (69) | 437 (67) |
| Pack-year smoked (years), Mean (SD) | 21.4 (25.2) | 20.95 (25.36) |
| Season | ||
| Cold: October–March, N (%) | 189 (41) | 259 (40) |
| Warm: April–September, N (%) | 267 (59) | 389 (60) |
| Alcohol consumption (≥2 drinks per day), N (%) | 95 (21) | 132 (20) |
| Mean (SD), (IQR) of the exposure levels | ||
| Average of 365 days of PM2.5 (μg/m3) | 10.4 (1.28), (2.49) | 10.1 (1.31), (2.12) |
| Average of 365 days of NO2 (ppb) | 19.1 (2.40), (4.52) | 18.4 (2.35), (4.00) |
| Average of 365 days of O3 (ppb) | 23.7 (1.06), (1.39) | 24.0 (1.12), (1.45) |
| Average of 365 days of Temperature (°C) | 11.0 (0.64), (1.00) | 11.0 (0.60), (0.89) |
Abbreviations: N Number of participants or visits, SD Standard deviation, ppb is part per billion, Kg Kilogram, m Meters, C Celsius, IQR Interquartile range