Characteristics of subjects in the coke oven lung function surveillance system with at least two sets of lung function tests
| Group | Total | ||||
|---|---|---|---|---|---|
| Operation | Maintenance | Electricity | Other | ||
| SD, standard deviation. | |||||
| *Number and proportions of non-smokers, ex-smokers, and current-smokers in each group. | |||||
| †Duration up to the last lung function tests. | |||||
| ‡Pure history: subjects had only one type of work position during the surveillance period. | |||||
| §Mixed history: subjects had more than one type of work position during the surveillance period. | |||||
| ¶The numbers of subjects in calculation for FEV1, FVC, and FEV1/FVC are 580; for FEF25–75% 419. | |||||
| Subjects (no.) | 365 | 103 | 59 | 53 | 580 |
| Age at first test (years), mean (SD) | 36.8 (11.2) | 41.3 (12.0) | 40.4 (11.6) | 41.9 (12.5) | 38.4 (11.7) |
| Min-max (years) | 17.7–64.0 | 18.0–62.5 | 20.4–61.0 | 20.4–63.5 | 17.7–64.0 |
| Age at last test (years), mean (SD) | 44.5 (11.3) | 48.4 (11.7) | 48.1 (10.6) | 46.6 (11.4) | 45.8 (11.4) |
| Min-max (years) | 19.7–65.0 | 25.2–65.5 | 29.0–64.4 | 26.4–64.5 | 19.7–65.5 |
| Height (cm), mean (SD) | 170.6 (7.1) | 170.0 (5.6) | 171.3 (7.4) | 173.4 (7.4) | 170.8 (7.0) |
| Min-max (cm) | 152–191 | 154–185 | 154–191 | 161–194 | 152–194 |
| Non-smokers, no. (%)* | 57 (15.6) | 19 (18.5) | 6 (10.2) | 6 (11.3) | 88 (15.2) |
| Ex-smokers, no. (%)* | 104 (28.5) | 32 (31.0) | 24 (40.7) | 14 (26.4) | 174 (30.0) |
| Smoking duration, mean (SD) | 15.7 (10.7) | 20.4 (13.3) | 17.7 (10.9) | 15.1 (11.2) | 16.8 (11.4) |
| Current smokers, no. (%)* | 204 (55.9) | 52 (50.5) | 29 (49.1) | 33 (62.3) | 318 (54.8) |
| Pack-years, mean (SD) | 14.9 (16.2) | 18.5 (21.5) | 23.1 (27.6) | 17.2 (29.3) | 16.5 (20.0) |
| Duration in “operation” (years)†, mean (SD) | 13.1 (7.5) | 0.9 (2.3) | 0.2 (1.2) | 0.9 (1.7) | 8.5 (8.5) |
| Duration other than in “operation” (years)†, mean (SD) | 0.6 (1.9) | 16.0 (8.3) | 16.9 (6.7) | 14.5 (8.5) | 6.3 (9.0) |
| Pure history‡, no. (%) | 290 (79.5) | 52 (50.5) | 36 (61.0) | 29 (54.7) | 407 (70.2) |
| Mixed history§, no. (%) | 75 (20.5) | 51 (49.5) | 23 (39.0) | 24 (45.3) | 173 (29.8) |
| % of predicted value at first test time¶, mean (SD) | |||||
| FVC | 85.6 (12.9) | 86.0 (10.5) | 87.2 (10.6) | 87.1 (11.9) | 86.0 (12.2) |
| FEV1 | 84.5 (15.5) | 85.1 (13.4) | 85.6 (13.7) | 83.9 (14.8) | 84.7 (14.9) |
| FEV1/FVC | 97.8 (10.6) | 98.4 (9.0) | 97.1 (8.9) | 95.8 (10.1) | 97.7 (10.1) |
| FEF25–75% | 81.6 (26.1) | 82.3 (35.6) | 83.2 (29.4) | 90.4 (30.6) | 82.3 (28.5) |