Table 2.
Intraprotocol and interprotocol interreader agreement and 95% confidence interval of the individual equivalence index (interprotocol minus intraprotocol interreader agreement)
| Item | Interreader agreement rate |
|---|---|
| Focal bone marrow abnormalities | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
688/750 (91.73%) 1361/1500 (90.73%) − 1.27 to 1.20 |
| Juxtadiscal Modic changes | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
1302/1500 (86.80%) 2582/3000 (86.07%) − 1.03 to 1.07 |
| Degenerative changes at margins of vertebral bodies | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
1996/3000 (66.53%) 4036/6000 (67.27%) − 1.07 to 1.01 |
| Schmorl’s nodes | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
1204/1500 (80.27%) 2406/3000 (80.20%) − 1.17 to 1.32 |
| Endplate fractures | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
1480/1500 (98.67%) 2968/3000 (98.93%) − 0.33 to 0.32 |
| Foraminal stenosis | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
1311/1500 (87.40%) 2608/3000 (86.93%) − 1.02 to 1.05 |
| Facet arthropathy | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
1104/1500 (73.60%) 2212/3000 (73.73%) − 1.32 to 1.38 |
| Spondylolysis | |
|
Intraprotocol (standard vs. standard) Interprotocol (standard vs. simplified) 95% confidence interval for individual equivalence index (%) |
1490/1500 (99.33%) 2980/3000 (99.33%) − 0.27 to 0.25 |
Note: Total number of observations varies between items in the following manner for the standard protocol: focal bone marrow abnormalities: 50 × 5 vertebrae × 3 readers; juxtadiscal Modic changes, Schmorl’s nodes, endplate fractures, facet arthropathy, and spondylolysis: 50 × 5 levels × 2 sides × 3 readers; degenerative changes at the margins of vertebral bodies: 50 × 5 levels × 4 vertebral corners × 3 readers. For the interprotocol agreement (standard vs. simplified), the total number of observations is doubled