Interobserver agreement for CT scores allocated to infants with NBS-diagnosed CF at 1 year of age during initial scoring of LCFC scans (n=65)
| (a) Bronchial dilatation (maximum possible score=72) | ||||||
|---|---|---|---|---|---|---|
| κ=0.21 (0.05; 0.37) | Scorer A | |||||
| 0 | 1 | 2 | 3 | 4 | 5 | |
| Scorer B | ||||||
| 0 | 48 | – | – | – | – | |
| 1 | 6 | – | – | – | – | – |
| 2 | 4 | 3 | 1 | – | – | – |
| 3 | 1 | – | – | – | – | – |
| 4 | 1 | – | – | – | – | – |
| 5 | – | 1 | – | – | – | – |
| (b) Air trapping (maximum possible score=27) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| κ=0.66 (0.49; 0.83) | Scorer A | |||||||||
| 0 | 1 | 2 | 3 | 4 | 5 | 7 | 8 | 15 | 16 | |
| Scorer B | ||||||||||
| 0 | 37 | – | 1 | – | – | – | – | – | – | – |
| 1 | 6 | 3 | – | – | – | – | – | – | – | – |
| 2 | 3 | – | 1 | 1 | – | – | – | – | – | – |
| 3 | 1 | 1 | 1 | 2 | – | – | – | – | – | – |
| 4 | – | – | – | – | 2 | – | – | – | – | – |
| 5 | – | – | – | – | 2 | – | – | – | – | – |
| 7 | – | – | – | – | – | 1 | – | – | – | – |
| 8 | 1 | – | – | 1 | – | – | – | – | – | – |
| 15 | – | – | – | – | – | – | – | – | – | 1 |
| 16 | – | – | – | – | – | – | – | – | – | – |
| (c) Total CT score (maximum possible score=243) | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| κ=0.34 (0.20 to 0.49) | Scorer A | |||||||||||||||||
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 12 | 13 | 14 | 17 | 19 | 25 | 30 | |
| Scorer B | ||||||||||||||||||
| 0 | 7 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 1 | 5 | 5 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 2 | 7 | 1 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 3 | 5 | – | 2 | 1 | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 4 | 3 | 1 | – | 2 | – | 1 | – | – | – | – | – | – | – | – | – | – | – | – |
| 5 | – | 4 | 1 | 1 | – | 1 | – | – | – | – | – | – | – | – | – | – | – | – |
| 6 | 1 | – | 1 | – | 1 | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 7 | 1 | 1 | 1 | – | – | 1 | – | – | – | – | – | – | – | – | – | – | – | – |
| 8 | 1 | – | – | 1 | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 9 | – | – | – | – | 1 | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 10 | – | – | – | – | – | – | – | – | – | – | 1 | – | – | – | – | – | – | – |
| 12 | – | – | – | – | – | 1 | – | – | – | – | – | – | – | – | – | – | – | – |
| 13 | – | – | – | – | – | 2 | – | – | – | – | – | – | – | – | – | – | – | – |
| 14 | 1 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 17 | – | – | – | – | – | – | – | 1 | – | – | – | – | – | – | – | – | – | – |
| 19 | – | – | – | – | – | – | – | – | – | – | – | 1 | – | – | – | – | – | – |
| 25 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| 30 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | 1 | – |
Shaded cells across the diagonals within each table represent identical results by scorers A and B using the Brody-II scoring system. For air trapping scores >5 and total CT scores >12, only those for which any values were obtained are shown. Although scorer B identified more abnormalities on scans than scorer A as indicated by values generally falling below the shaded diagonal cells (17 (26%) vs 5 (7%) for bronchial dilatation; 27 (42%) vs 17 (26%) for air trapping, the severity of changes were generally very minor, with only seven (11%) and two (3%) of patients having a total CT score ≥12 or 5% of the total possible score). κ=κ coefficient (95% CI) as a measure of agreement of CT subscores and total scores allocated by scorer A and B. It can be seen that the majority of discrepancies for bronchodilatation occurred when changes were deemed to be very minor(1–3) by one scorer and absent [0] by the other.
LCFC, London Cystic Fibrosis Collaboration; NBS, newborn screened.