Table 1.
Details of the datasets and study populations in the USA and UK, respectively
| US data | UK data | |
| Sample size | 9463 | 3055 |
| No of FEV1 measures per person (median (IQR), (full range)) |
24 (11–40), (1–199) | 4 (2–7), (1–17) |
| No of individuals with one FEV1 measure (%) | 251 (2.7) | 398 (13.0) |
| No of FEV1 measures per person per year (median (IQR)) | 4 (3–6) | 1 (1–1) |
| Time in years between first and last FEV1 measurement included in the study per person (median (IQR))* | 5.5 (2.7–8.4) | 4.9 (2.2–7.5) |
| Informative drop-out during study period (%) | ||
| Lung transplants | 142 (1.5) | 27 (0.9) |
| Deaths | 263 (2.8) | 70 (2.3) |
| Sex (%) | ||
| Female | 4625 (48.9) | 1457 (47.7) |
| Male | 4838 (51.1) | 1598 (52.3) |
| Year of birth (median) (IQR) | 1996 (1991–2002) | 1996 (1991–2002) |
| Race (%) | ||
| Non-Caucasian | 384 (4.1) | 71 (2.3) |
| Caucasian | 9083 (95.9) | 2984 (97.7) |
| Age at diagnosis in years (median (IQR)) | 0.3 (0.0–1.2) | 0.2 (0.0–1.0) |
| Diagnosis by newborn screening (%) | 1079 (11.4) | 501 (16.3) |
| %FEV1 at age 6 (mean (SD)) | 92.96 (17.7) | 88.17 (16.9) |
*Excluding individuals with only one FEV1 measurement.
FEV1, forced expiratory volume in 1 s.