Skip to main content
. 2014 Sep 24;14:994. doi: 10.1186/1471-2458-14-994

Table 3.

The baseline characteristics of all participants in the WHZH cohort

Variables Total (n = 4812) Wuhan (n = 3053) Zhuhai (n = 1759)
Gender, (female, n (%)) 3252 (67.6) 1973 (64.6) 1279 (72.7)
Age (years) 53.1 (13.0) 53.0 (13.3) 53.3 (12.4)
Age (years), n (%)
  18-44 1256 (26.1) 796 (26.1) 460 (26.2)
  45-59 2068 (43.0) 1315 (43.1) 753 (42.8)
  60-80 1488 (30.9) 942 (30.9) 546 (31.0)
Education, n (%)
  Primary school or illiteracy 1219 (25.3) 644 (21.1) 575 (32.7)
  Middle school 1655 (34.4) 1067 (34.9) 588 (33.4)
  High school 1338 (27.8) 965 (31.6) 373 (21.2)
  University or college or higher 600 (12.5) 377 (12.3) 223 (12.7)
Income (Yuan/year) # , n (%)
  ≤39999 2642 (54.9) 1856 (60.8) 786 (44.7)
  40000-119999 1886 (39.2) 1104 (36.2) 782 (44.5)
  ≥120000 201 (4.2) 57 (1.9) 144 (8.2)
  Missing, n (%) 83 (1.7) 36 (1.2) 47 (2.7)
Current smoker, n (%) 795 (16.5) 597 (19.2) 198 (11.3)
Current drinker, n (%) 666 (13.8) 537 (17.6) 129 (7.3)
Physical activity, (yes, n (%)) 2346 (48.8) 1353 (44.3) 993 (56.4)
BMI (kg/m 2 ) 24.0 (3.5) 24.1 (3.4) 23.7 (3.5)
Waist circumference (cm) 818.7 (97.6) 820.9 (97.7) 814.8 (97.3)
Blood pressure (mmHg)
  Systolic blood pressure 131.5 (20.3) 131.0 (20.5) 132.4 (20.0)
  Diastolic blood pressure 77.4 (15.0) 76.6 (16.8) 78.7 (11.2)
  Missing, n (%) 60 (1.2) 37 (1.2) 23 (1.3)
Exhaled carbon monoxide (μg/L) 7.7 (9.9) 8.5 (11.0) 6.3 (7.4)
  Missing, n (%) 27 (0.6) 0 (0%) 27 (1.5)
Exhaled nitrogen oxide (ppb) 24.9 (17.3) 27.2 (16.3) 20.9 (18.4)
  Missing, n (%) 228 (4.7) 121 (4.0) 107 (6.1)
Lung function
  FVC (ml) 2479.6 (698.9) 2566.5 (711.7) 2327.9 (649.0)
  FEV1 (ml) 2159.4 (610.7) 2200.8 (615.1) 2087.2 (596.4)
  FEV1/FVC (%) 87.5 (8.9) 86.9 (9.2) 89.9 (7.7)
  Missing, n (%) 107 (2.2) 62 (2.0) 45 (2.6)
Heart rate variable
  TP (msec2) 809.4 (461.8, 1413.8) 818.0 (464.8, 1413.6) 798.8 (450.9, 1417.3)
  LF (msec2) 218.8 (107.1, 418.4) 219.0 (107.7, 426.2) 218.8 (106.3, 406.2)
  HF (msec2) 119.7 (56.4, 250.8) 125.8 (59.9, 259.9) 110.8 (51.1, 234.6)
  Missing, n (%) 315 (6.5) 203(6.6) 112(6.4)

Variables are presented as mean ± SD, percentage or median (25th, 75th quartile). BMI, body mass index; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; TP, total power; LF, low frequency; HF, high frequency. #Chinese RMB.