Table 5

 Level of agreement between reviewer pairs

Inter-raterReviewer 1 versus 2Reviewer 2 versus 3Reviewer 1 versus 3
κ (95% CI)κ maxκ/κ maxκ (95% CI)κ maxκ/κ maxκ (95% CI)κ maxκ/κ max
*Based on seven categories of seriousness;
†Based on preventability scores (score 1–3 preventable, score 4–6 not preventable).
Event type0.36 (0.32 to 0.40)0.980.370.35 (0.33 to 0.39)0.770.450.51 (0.47 to 0.55)0.880.57
Seriousness*0.36 (0.32 to 0.40)0.630.590.37 (0.33 to 0.41)0.590.630.29 (0.25 to 0.33)0.780.38
Serious v not serious0.53 (0.45 to 0.61)0.820.640.58 (0.50 to 0.66)0.800.730.37 (0.29 to 0.45)0.980.37
Preventability decision (yes/no)0.31 (0.25 to 0.37)0.810.380.30 (0.24 to 0.36)0.810.370.50 (0.42 to 0.58)0.990.51
Preventability score0.30 (0.24 to 0.36)0.810.370.24 (0.18 to 0.30)0.830.290.45 (0.39 to 0.51)0.900.50
Preventability category†0.33 (0.27 to 0.39)0.800.420.31 (0.25 to 0.37)0.810.380.51 (0.45 to 0.57)0.960.53
Intra-raterReviewer 1Reviewer 2Reviewer 3
Event type0.64 (0.52 to 0.76)0.740.870.55 (0.45 to 0.65)0.870.630.69 (0.59 to 0.79)0.880.78