Table 4.

Agreement for subregion >50% thickness deep cartilage loss (DCL), pooled.

Agreement metric	Inter-reader	Intra-reader
Exact agreement for subregion presence/absence of >10% surface area DCL (n/N)	97.7% (625/640)	98.8% (632/640)
Kappa for subregion presence/absence of >10% surface area DCL [95% CI*]	0.71 [0.50–0.82]	0.78 [0.67–0.94]
Weighted kappa for all sizes of subregion DCL (size grades 0 to 3) [95% CI*]	0.43 [0.28–0.54]	0.50 [0.40–0.60]
Weighted kappa for maximum subregion DCL size grade within an articular surface [95% CI*]	0.73 [0.58–0.80]	0.82 [0.73–0.86]
Weighted kappa for maximum subregion DCL size grade within a joint compartment [95% CI*]	0.75 [0.59–0.85]	0.83 [0.73–0.88]

^*Bootstrap 95% confidence interval (CI), with resampling at the subject level.DCL, deep cartilage loss.

n/N = number of agreements/number of subregions scored (640 = 40 knees x 16 subregions)