Table 1 Baseline characteristics of participants and air pollutants exposure in UK Biobank cohort
From: Associations of long-term exposure to nitrogen oxides with all-cause and cause-specific mortality
Variables | Overall | Alive | Death |
|---|---|---|---|
(n = 502,040) | (n = 457,950) | (n = 44,090) | |
Age, mean (SD), years | 56.5 (8.1) | 56.0 (8.1) | 61.7 (6.4) |
Sex, % | |||
Male | 228,851 (45.6) | 202,905 (44.3) | 25,946 (58.8) |
Female | 273,189 (54.4) | 255,045 (55.7) | 18,144 (41.2) |
Body mass index, kg/m2, % | |||
Underweight (< 18.5) | 2620 (0.5) | 2220 (0.5) | 400 (0.9) |
Normal (18.5–24.9) | 162,280 (32.3) | 150,824 (32.9) | 11,456 (26.0) |
Overweight (25.0–29.9) | 211,908 (42.2) | 194,075 (42.4) | 17,833 (40.4) |
Obese (≥ 30.0) | 122,073 (24.3) | 108,291 (23.6) | 13,782 (31.3) |
Household income, £ | |||
≤ 30,999 | 205,148 (40.9) | 180,451 (39.4) | 24,697 (56.0) |
> 30,999 | 219,820 (43.8) | 208,985 (45.6) | 10,835 (24.6) |
Ethnicity, % | |||
White | 472,256 (94.1) | 430,035 (93.9) | 42,221 (95.8) |
Non-white | 27,009 (5.4) | 25,433 (5.6) | 1576 (3.6) |
Residential area, % | |||
Rural | 68,581 (13.7) | 63,293 (13.8) | 5288 (12.0) |
Urban | 428,395 (85.3) | 389,907 (85.1) | 38,488 (87.3) |
Years of education, years, % | |||
≤ 7 | 85,170 (17.0) | 71,788 (15.7) | 13,382 (30.4) |
8–10 | 83,230 (16.6) | 76,717 (16.8) | 6513 (14.8) |
11–13 | 27,214 (5.4) | 25,201 (5.5) | 2013 (4.6) |
14–15 | 59,145 (11.8) | 54,267 (11.9) | 4878 (11.1) |
16–19 | 76,137 (15.2) | 70,088 (15.3) | 6049 (13.7) |
≥ 20 | 161,025 (32.1) | 151,023 (33.0) | 10,002 (22.7) |
Occupation, % | |||
Employed | 286,923 (57.2) | 273,058 (59.6) | 13,865 (31.4) |
Retired | 166,798 (33.2) | 142,223 (31.1) | 24,575 (55.7) |
Unemployed, home maker or other | 45,372 (9.0) | 39,968 (8.7) | 5404 (12.3) |
Smoking status, % | |||
Never | 273,323 (54.4) | 256,343 (56.0) | 16,980 (38.5) |
Previous | 172,865 (34.4) | 154,472 (33.7) | 18,393 (41.7) |
Current | 52,906 (10.5) | 44,583 (9.7) | 8323 (18.9) |
Alcohol consumption, % | |||
Never | 22,367 (4.5) | 20,159 (4.4) | 2208 (5.0) |
Previous | 18,075 (3.6) | 15,178 (3.3) | 2897 (6.6) |
Current | 459,949 (91.6) | 421,152 (92.0) | 38,797 (88.0) |
Physical activity, % | |||
Low | 71,523 (14.2) | 64,183 (14.0) | 7340 (16.6) |
Moderate | 156,436 (31.2) | 143,876 (31.4) | 12,560 (28.5) |
High | 156,986 (31.3) | 145,382 (31.7) | 11,604 (26.3) |
Missing | 117,095 (23.3) | 104,509 (22.8) | 12,586 (28.5) |
Baseline cancer, % | |||
Yes | 46,512 (9.3) | 38,555 (8.4) | 7957 (18.0) |
No | 455,528 (90.7) | 419,395 (91.6) | 36,133 (82.0) |
Baseline hypertension, % | |||
Yes | 198,916 (39.6) | 173,424 (37.9) | 25,492 (57.8) |
No | 303,124 (60.4) | 284,526 (62.1) | 18,598 (42.2) |
Baseline diabetes, % | |||
Yes | 27,077 (5.4) | 21,249 (4.6) | 5828 (13.2) |
No | 474,963 (94.6) | 436,701 (95.4) | 38,262 (86.8) |
NOx, mean (SD), μg/m3 | 24.5 (11.8) | 24.4 (11.7) | 26.7 (11.6) |
NO2, mean (SD), μg/m3 | 16.6 (6.6) | 16.5 (6.6) | 17.9 (6.4) |
