Table 2.
Inter-observer variability in venous and arterial flow measurements in adult and fetal vessels.
| Adult measurements | Carotid artery | Jugular vein | ||||
|---|---|---|---|---|---|---|
| Image score | 0 | 1 | 2 | 0 | 1 | 2 |
| Number of flow measurements | 60 | 60 | 36 | 56 | 50 | 33 |
| Mean flow difference in flow measurements of the observers ± SD (%) | 7.1 ± 4.2 | 8.5 ± 5.7 | 39.7 ± 34.2 | 3.2 ± 2.6 | 5.8 ± 6.0 | 51.6 ± 55.6 |
| ICC (95% CI) | 0.99 (0.98–0.99) | 0.98 (0.96–0.99) | 0.81 (0.64–0.90) | 0.99 (0.99–1.0) | 0.99 (0.99–1.0) | 0.90 (0.81–0.95) |
| Significance of the difference—compared to scans rated with zero | – | p = 0.86 | p < 0.0001 | – | p = 0.81 | p < 0.0001 |
| Fetal measurements | Artery | Vein | ||||
|---|---|---|---|---|---|---|
| Image score | 0 | 1 | 2 | 0 | 1 | 2 |
| Number of flow measurements | 3 | 23 | 12 | 5 | 7 | 8 |
| Mean flow difference in flow measurements of the observers ± SD (%) | 4.3 ± 4.8 | 5.8 ± 5.1 | 26.0 ± 23.4 | 4.2 ± 4.4 | 5.3 ± 3.1 | 28.5 ± 22.4 |
| ICC (95% CI) | 0.99 (0.78–1.0) | 0.99 (0.97–0.99) | 0.86 (0.51–0.96) | 0.96 (0.65–0.99) | 0.99 (0.94–0.99) | 0.76 (− 0.20 to 0.95) |
| Significance of the difference—compared to scans rated with zero | – | p = 0.96 | p = 0.03 | – | p = 0.99 | p = 0.02 |
ICC intra class correlation, SD standard deviation, CI confidence interval.
Significant values are in bold.