Table 2.
Intra- and inter-rater measures’ reliability results based on different measurement methods on disc height.
| Level/Diagnosis | N | Intra-rater reliability |
Inter-rater_ICC (95 % CI) | ||
|---|---|---|---|---|---|
| Rater 1_ICC (95 % CI) | Rater 2_ICC (95 % CI) | ||||
| Method 1 | L1-L2 | 332 | 0.894 (0.870, 0.914) | ||
| L2-L3 | 332 | 0.873 (0.844, 0.896) | |||
| L3-L4 | 332 | 0.898 (0.875, 0.917) | |||
| L4-L5 | 332 | 0.924 (0.907, 0.938) | |||
| L5-S1 | 332 | 0.916 (0.896, 0.931) | |||
| Lumbar disc herniation | 340 | 0.900 (0.868, 0.925) | |||
| Lumbar spinal stenosis | 645 | 0.873 (0.851, 0.893) | |||
| Spondylolisthesis | 175 | 0.529 (0.448, 0.601) | |||
| Normal | 500 | 0.954 (0.946, 0.960) | |||
| All | 1660 | 0.960 (0.951, 0.972) | 0.967 (0.958, 0.982) | 0.902, (0.892, 0.910) | |
| Method 2 | L1-L2 | 332 | 0.971 (0.965, 0.977) | ||
| L2-L3 | 332 | 0.953 (0.942, 0.962) | |||
| L3-L4 | 332 | 0.940 (0.927, 0.952) | |||
| L4-L5 | 332 | 0.926 (0.909, 0.940) | |||
| L5-S1 | 332 | 0.929 (0.913, 0.942) | |||
| Lumbar disc herniation | 340 | 0.951 (0.934, 0.963) | |||
| Lumbar spinal stenosis | 645 | 0.977 (0.973, 0.980) | |||
| Spondylolisthesis | 175 | 0.556 (0.478, 0.625) | |||
| Normal | 500 | 0.931 (0.919, 0.942) | |||
| All | 1660 | 0.962 (0.947, 0.975) | 0.961 (0.957, 0.971) | 0.948 (0.943, 0.953) | |
| Method 3_ Anterior disc height | L1-L2 | 332 | 0.983 (0.979, 0.986) | ||
| L2-L3 | 332 | 0.951 (0.940, 0.960) | |||
| L3-L4 | 332 | 0.942 (0.929, 0.953) | |||
| L4-L5 | 332 | 0.900 (0.877, 0.919) | |||
| L5-S1 | 332 | 0.938 (0.924, 0.950) | |||
| Lumbar disc herniation | 340 | 0.950 (0.933, 0.963) | |||
| Lumbar spinal stenosis | 645 | 0.977 (0.973, 0.980) | |||
| Spondylolisthesis | 175 | 0.675 (0.613, 0.729) | |||
| Normal | 500 | 0.930 (0.917, 0.941) | |||
| All | 1660 | 0.973 (0.964, 0.981) | 0.975 (0.962, 0.985) | 0.955 (0.950, 0.959) | |
| Method 3_ Posterior disc height | L1-L2 | 332 | 0.946 (0.933, 0.956) | ||
| L2-L3 | 332 | 0.933 (0.918, 0.946) | |||
| L3-L4 | 332 | 0.934 (0.918, 0.946) | |||
| L4-L5 | 332 | 0.929 (0.913, 0.943) | |||
| L5-S1 | 332 | 0.873 (0.845, 0.896) | |||
| Lumbar disc herniation | 340 | 0.939 (0.918, 0.954) | |||
| Lumbar spinal stenosis | 645 | 0.971 (0.966, 0.975) | |||
| Spondylolisthesis | 175 | 0.479 (0.465, 0.487) | |||
| Normal | 500 | 0.923 (0.909, 0.935) | |||
| All | 1660 | 0.957 (0.942, 0.968) | 0.955 (0.946, 0.962) | 0.928 (0.921, 0.934) | |
| Method 4 | L1-L2 | 332 | 0.890 (0.865, 0.910) | ||
| L2-L3 | 332 | 0.946 (0.934, 0.956) | |||
| L3-L4 | 332 | 0.903 (0.880, 0.921) | |||
| L4-L5 | 332 | 0.900 (0.877, 0.919) | |||
| Lumbar disc herniation | 272 | 0.836 (0.779, 0.880) | |||
| Lumbar spinal stenosis | 516 | 0.975 (0.970, 0.979) | |||
| Spondylolisthesis | 140 | 0.445 (0.345, 0.536) | |||
| Normal | 400 | 0.931 (0.898, 0.959) | |||
| All | 1328 | 0.921(0.913, 0.925) | 0.930 (0.925, 0.938) | 0.917 (0.908, 0.925) | |
| Method 5_ Anterior disc material length | L1-L2 | 332 | 0.848 (0.814, 0.875) | ||
| L2-L3 | 332 | 0.760 (0.711, 0.802) | |||
| L3-L4 | 332 | 0.861 (0.830, 0.886) | |||
| L4-L5 | 332 | 0.671 (0.607, 0.726) | |||
| L5-S1 | 332 | 0.845 (0.811, 0.873) | |||
| Lumbar disc herniation | 340 | 0.800 (0.739, 0.847) | |||
| Lumbar spinal stenosis | 645 | 0.872 (0.852, 0.889) | |||
| Spondylolisthesis | 175 | 0.384 (0.283, 0.479) | |||
| Normal | 500 | 0.803 (0.769, 0.832) | |||
| All | 1660 | 0.928 (0.916, 0.935) | 0.921 (0.914, 0.931) | 0.812 (0.795, 0.828) | |
| Method 5_ Posterior disc material length | L1-L2 | 332 | 0.802 (0.794, 0.820) | ||
| L2-L3 | 332 | 0.786 (0.771, 0.802) | |||
| L3-L4 | 332 | 0.808 (0.767, 0.842) | |||
| L4-L5 | 332 | 0.427 (0.418, 0.440) | |||
| L5-S1 | 332 | 0.873 (0.845, 0.897) | |||
| Lumbar disc herniation | 340 | 0.842 (0.793, 0.880) | |||
| Lumbar spinal stenosis | 645 | 0.744 (0.708, 0.777) | |||
| Spondylolisthesis | 175 | 0.387 (0.293, 0.474) | |||
| Normal | 500 | 0.740 (0.698, 0.777) | |||
| All | 1660 | 0.912 (0.901, 0.923) | 0.902 (0.892, 0.915) | 0.740 (0.718, 0.761) | |
| Method 6 | L1-L2 | 332 | 0.956 (0.946, 0.964) | ||
| L2-L3 | 332 | 0.935 (0.920, 0.948) | |||
| L3-L4 | 332 | 0.931 (0.915, 0.944) | |||
| L4-L5 | 332 | 0.932 (0.917, 0.945) | |||
| L5-S1 | 332 | 0.929 (0.912, 0.942) | |||
| Lumbar disc herniation | 340 | 0.944 (0.926, 0.958) | |||
| Lumbar spinal stenosis | 645 | 0.972 (0.967, 0.976) | |||
| Spondylolisthesis | 175 | 0.560 (0.483, 0.629) | |||
| Normal | 500 | 0.918 (0.903, 0.931) | |||
| All | 1660 | 0.945 (0.936, 0.957) | 0.927 (0.924, 0.933) | 0.938 (0.932, 0.944) | |
| Method 7 | L1-L2 | 332 | 0.948 (0.936, 0.958) | ||
| L2-L3 | 332 | 0.856 (0.825, 0.883) | |||
| L3-L4 | 332 | 0.968 (0.960, 0.974) | |||
| L4-L5 | 332 | 0.706 (0.647, 0.756) | |||
| L5-S1 | 332 | 0.827 (0.790, 0.858) | |||
| Lumbar disc herniation | 340 | 0.912 (0.883, 0.934) | |||
| Lumbar spinal stenosis | 645 | 0.962 (0.956, 0.968) | |||
| Spondylolisthesis | 175 | 0.753 (0.688, 0.810) | |||
| Normal | 500 | 0.801 (0.767, 0.830) | |||
| All | 1660 | 0.944 (0.936, 0.951) | 0.938 (0.929, 0.946) | 0.897 (0.887, 0.906) | |
| Method 8 | L1-L2 | 332 | 0.938 (0.923, 0.949) | ||
| L2-L3 | 332 | 0.824 (0.786, 0.856) | |||
| L3-L4 | 332 | 0.846 (0.812, 0.874) | |||
| L4-L5 | 332 | 0.810 (0.770, 0.844) | |||
| Lumbar disc herniation | 272 | 0.993 (0.990, 0.995) | |||
| Lumbar spinal stenosis | 516 | 0.997 (0.996, 0.997) | |||
| Spondylolisthesis | 140 | 0.993 (0.992, 0.995) | |||
| Normal | 400 | 0.993 (0.992, 0.995) | |||
| All | 1328 | 0.932 (0.922, 0.939) | 0.922 (0.917, 0.931) | 0.995 (0.994, 0.995) | |
N: number of levels; ICC: Intraclass correlation coefficient; 95 % CI: 95 % confidence intervals.
Intra-rater and inter-rater reliability were assessed by intra-class correlation coefficient (ICC) and their 95 % confidence intervals (95 % CI). The excellent, good, moderate, and poor reliability were presented as the values of ICC greater than 0.90, between 0.75 and 0.9, between 0.5 and 0.75, and less than 0.5, respectively.