Table 1.
Characteristics participants included in sample 1 and sample 2
| Sample 1 | Sample 2 (verification) | |
|---|---|---|
|
n |
8128 |
5308 |
|
Males, n (%) |
3483 (43) |
2133 (40) |
|
Age, median (min-max) |
47 (18–89) |
48 (21–90) |
|
Smoking status, n (%) |
|
|
| Never, n (%) |
3277 (40) |
2154 (41) |
| Ex, n (%) [median (min-max)] |
2882 (36) [8 (0–86)] |
2014 (39) [7 (0–100)] |
| Current, n (%) [median (min-max)] |
1936 (24) [15 (0–100)] |
1065 (20) [16 (0–81)] |
|
ETS exposure, n (%) |
|
|
| In utero |
867 (13) |
559 (13) |
| ≥ 1 hour/day |
1788 (24) |
1029 (21) |
| At the workplace |
565 (7) |
303 (6) |
|
Lung function, mean (sd) |
|
|
| FEV1 (ml) |
3412 (831) |
3331 (840) |
| FEV1pp (%)1 |
102 (14) |
102 (14) |
| FEV1/FVC (%) |
77 (7) |
76 (7) |
| Spirometry available, n | 7635 | 5070 |
The second sample (sample 2) was used to verify the initial findings from sample 1, both samples are part of the LifeLines population-based cohort study.
1 FEV1pp = FEV1 as percentage predicted based on reference equations constructed by Quanjer et al. [28].