TABLE 3.
Summary of Differences in PFT Measurements
| PFT Result | All Measurements (N =137) | Outdoor Workers (N =101) | Indoor Workers (N =36) | P* |
|---|---|---|---|---|
| FVC Percent Predicted (% points) | ||||
| Mean (SD) | 1.26 (4.01) | 1.55 (4.18) | 0.46 (3.44) | 0.13 |
| Min | 15 | 15 | 8 | |
| Max | 11 | 11 | 6 | |
| FEV1 Percent (% points) | ||||
| Predicted Mean (SD) | 1.60 (4.99) | 1.79 (5.43) | 1.06 (3.54) | 0.37 |
| Min | 26 | 26 | 7 | |
| Max | 10 | 10 | 9 | |
| FEV1/FVC Percent Predicted (% points) | ||||
| Mean (SD) | 0.37 (3.34) | 0.28 (3.70) | 0.63 (2.09) | 0.50 |
| Min | 15 | 15 | 5 | |
| Max | 6 | 6 | 4 | |
| FEF25–75 Percent Predicted (% points) | ||||
| Mean (SD) | 0.69 (14.07) | 1.08 (15.30) | 0.40 (10.02) | 0.52 |
| Min | 62 | 62 | 15 | |
| Max | 26 | 26 | 26 | |
| PEFR Percent Predicted (% points) | ||||
| Mean (SD) | 2.51 (17.70) | 1.14 (18.59) | 6.29 (14.59) | 0.10 |
| Min | 54 | 54 | 23 | |
| Max | 59 | 59 | 34 | |
As differences in percent predicted values across work shifts for all participants and participants stratified by primary work location (outdoor vs indoor).
FEV1, forced expiratory volume in the first second; FEF25–75, forced expiratory flow at 25% to 75%, FVC, forced vital capacity; PEFR, peak expiratory flow rate.
*
t test comparing the mean difference in PFT percent predicted values for outdoor and indoor workers.