Table 5.
Sensitivity analysis for smokers: mean (SE) postbronchodilator FEV1 decline in ml/year in the three categories* based on alternative LLN prediction equations for the base case population
| Category* | |||||||
|---|---|---|---|---|---|---|---|
| Non-obstructed | Discordant | Obstructed | p-value† | ||||
| (LLN-Fixed-) | (LLN-Fixed+) | (LLN+Fixed+) |
Overall difference between categories |
LLN-Fixed+ versus LLN-Fixed- |
LLN-Fixed+ versus LLN+Fixed+ |
||
| Swanney [6], 2008 | FEV1 decline | -21 (3) | -21 (7) | -50 (5) | < 0.001 | 0.973 | < 0.001 |
| n | 578 | 138 | 292 | ||||
| ECSC [25], 1993 | FEV1 decline | -22 (3) | -24 (15) | -50 (3) | < 0.001 | 0.870 | 0.094 |
| n | 578 | 29 | 452 | ||||
| Kuster [28], 2008 | FEV1 decline | -20 (3) | -8 (20) | -48 (3) | < 0.001 | 0.599 | 0.087 |
| n | 563 | 14 | 557 | ||||
| Falaschetti [26], 2004 | FEV1 decline | -21 (3) | -21 (18) | -47 (3) | < 0.001 | 0.985 | 0.153 |
| n | 546 | 24 | 542 | ||||
| Brandli [27], 2000 | FEV1 decline | -21 (3) | -4 (11) | -49 (4) | < 0.001 | 0.026 | < 0.001 |
| n | 575 | 60 | 397 | ||||
| Hankinson [29], 1999 | FEV1 decline | -21 (3) | -37 (22) | -48 (3) | < 0.001 | 0.468 | 0.620 |
| n | 569 | 18 | 523 | ||||
ECSC: European Community for Steel and Coal; FEV1: forced expiratory volume in 1 s; LLN: lower limit of normal; SD: standard deviation
* based on reference equations for LLN as indicated in first column
† between group differences were analyzed using random coefficient regression models with random intercept and random slope; adjustment for inhaled corticosteroid use