Table 9.
Comparison of 3-beat averaged mean and median of median % error for all variables.
| Mean (median) of % error | ||||||
|---|---|---|---|---|---|---|
| Variable type |
Local vs. core observer % error (119 variables) |
Core lab inter- observer % error (119 variables) |
Core lab inter- observer % error |
Core lab intra- observer % error |
P-value (local/core vs. core inter- observer % error)* |
P-value (core inter- vs. core intra- observer % error)† |
| A | 9.7 (7.3) | 6.8 (5.1) | 6.8 (5.1) | 1.5 (0.9) | <.001 | <.001 |
| C2 | 13.6 (8.4) | 10.1 (6.7) | 10.0 (7.0) | 4.6 (2.5) | <.001 | <.001 |
| C3 | 20.8 (12.9) | 13.1 (9.7) | 14.4 (10.9) | 5.8 (3.7) | <.001 | <.001 |
| C4 | 22.2 (16.5) | 18.8 (13.4) | 18.8 (14.0) | 8.4 (5.2) | <.001 | <.001 |
| D | 13.2 (7.9) | 8.7 (5.2) | 8.7 (5.2) | 4.2 (2.1) | <.001 | <.001 |
| I | 19.1 (5.2) | 5.5 (3.9) | 5.5 (3.9) | 3.9 (2.4) | <.001 | 0.018 |
| S | 35.9 (27.5) | 40.5 (38.6) | 40.5 (38.6) | 19.9 (16.3) | 0.004 | <.001 |
| T | 10.8 (5.1) | 8.9 (4.4) | 8.9 (4.4) | 5.5 (2.5) | <.001 | <.001 |
| V | 9.9 (5.6) | 6.2 (4.3) | 6.2 (4.3) | 4.2 (2.7) | <.001 | <.001 |
| R | 4.0 (1.9) | 2.9 (1.6) | 3.2 (1.6) | 2.0 (0.8) | <.001 | <.001 |
These have been classified using the schema detailed in the text, where A = area; C2, C3, C4 = calculated from 2, 3 and 4 variables respectively; D = dimension; I = integral; S = slope; T = Doppler time interval; V = velocity, and R = heart rate. Local vs. core, core lab inter-observer and core lab intra-observer % error have been calculated for all classes of variables. Percent error statistics are based on data from 150 variables unless otherwise noted.
*
Local vs. Core lab observer %error vs. Core lab inter-observer %error based on 119 variables
†
Core lab inter-observer vs. Core lab intra-observer %error based on 150 variables