Initial (I) and 15 follow up (F) spirometry tests: the time interval from the initial survey and the number of participants for each survey
| Survey | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| I | F1 | F2 | F3 | F4 | F5 | F6 | F7 | F8 | F9 | F10 | F11 | F12 | F13 | F14 | F15 | |
| *Months from initial survey. | ||||||||||||||||
| Interval* | 0 | 1 | 2 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 18 | 21 | 24 | 27 | 30 | 36 |
| Miners (n) | 317 | 228 | 225 | 229 | 210 | 214 | 241 | 220 | 225 | 225 | 193 | 154 | 167 | 190 | 164 | 190 |
| Referents (n) | 132 | 73 | 96 | 121 | 0 | 131 | 130 | 110 | 121 | 125 | 122 | 110 | 114 | 0 | 119 | 0 |