Table 1.
Demographic characteristics and baseline pulmonary function in the tea worker and comparison groups
| Characteristics | Tea Workers (N = 91) | Comparison (N = 32) | p |
|---|---|---|---|
| Age (year) (mean ± SD) | 40.6 ± 10.4 | 41.1 ± 9.1 | 0.81 |
| Height (cm) (mean ± SD) | 167.7 ± 6.3 | 169.5 ± 5.1 | 0.15 |
| Weight (kg) (mean ± SD) | 67.2 ± 8.1 | 69.6 ± 8.2 | 0.14 |
| Education level* | < 0.01 | ||
| Elementary | 18 (19.8%) | 0 (0.0%) | |
| Junior high | 27 (29.7%) | 0 (0.0%) | |
| Senior high | 45 (49.5%) | 26 (81.3%) | |
| University | 1 (1.1%) | 6 (18.7%) | |
| Race | 0.80 | ||
| Han | 83 (91.2%) | 30 (93.8%) | |
| Aboriginal | 7 (7.7%) | 2 (6.2%) | |
| Hakka | 1 (1.1%) | 0 (0.0%) | |
| Smoking | 0.86 | ||
| Never | 31 (34.1%) | 10 (31.2%) | |
| Ex-smoker | 16 (17.6%) | 7 (21.9%) | |
| Current | 44 (48.3%) | 15 (46.9%) | |
| Tea-drinking* | < 0.01 | ||
| Never | 3 (3.3%) | 8 (25.0%) | |
| Occasional | 22 (24.2%) | 11 (34.4%) | |
| Habitual | 66 (72.5%) | 13 (40.6%) | |
| Baseline pulmonary function† | |||
| FVC (L) (mean ± SD) | 4.05 ± 0.68 | 4.15 ± 0.58 | 0.41 |
| FVC (%pred‡) (mean ± SD) | 89.10 ± 10.38 | 89.42 ± 7.27 | 0.85 |
| FEV1 (L) (mean ± SD) | 3.66 ± 0.64 | 3.77 ± 0.59 | 0.39 |
| FEV1 (%pred) (mean ± SD) | 97.47 ± 12.63 | 98.30 ± 9.47 | 0.70 |
| FEV1/FVC (mean ± SD) | 90.47 ± 4.81 | 90.60 ± 4.67 | 0.90 |
| MMF (L/S) (mean ± SD) | 4.93 ± 1.29 | 4.99 ± 1.12 | 0.79 |
| MMF (%pred) (mean ± SD) | 123.78 ± 30.37 | 123.44 ± 23.73 | 0.95 |
*p value < 0.05 for two-sample t test, chi-square test, or Fisher's exact test
†FVC: forced vital capacity, FEV1: 1-second forced expiratory volume, MMF: maximal mid-expiratory flow rate; ‡pred = predicted value