Table 2.

The concordance between the seven investigators in the judgment of ultrasound characteristics, listed according to Gwet’s AC1, starting with the lowest concordance. The numbers in the characteristic/property/feature column identify the corresponding question answered by the investigators for each nodule. For comparison purposes, kappa is also shown as earlier studies used kappa values.

Characteristic/property/feature	No. of nodules analyzed	Interobserver mean (95% CI)		Intraobserver mean (95% CI)
		Gwet’s AC1 value	Fleiss kappa	Gwet’s AC1 value	Cohen’s kappa
6. Uncertain hyperechogenic spots	123	0.12 (0.05–0.19)	0.05 (0.00–0.10)	0.48 (0.42–0.54)	0.48 (0.42–0.53)
13/B. Mild/moderately vs very hypoechogenic nodulea	39	0.17 (0.06–0.27)	0.07 (−0.03–0.16)	0.63 (0.56–0.70)	0.57 (0.49–0.64)
12/B. Does a partially cystic nodule have an eccentric solid part?b	9	0.28 (−0.16–0.72)	0.26 (−0.09–0.60)	0.78 (0.70–0.86)	0.71 (0.61–0.81)
14. Irregular margins	123	0.34 (0.26–0.42)	0.18 (0.14–0.24)	0.62 (0.57–0.67)	0.51 (0.47–0.56)
4. Punctate echogenic foci	123	0.39 (0.29–0.49)	0.27 (0.21–0.33)	0.68 (0.63–0.72)	0.52 (0.48–0.57)
3. Back wall cystic figures	123	0.48 (0.38–0.57)	0.11 (0.07–0.16)	0.74 (0.70–0.78)	0.49 (0.43–0.55)
5. Microcalcification	123	0.53 (0.43–0.63)	0.29 (0.22–0.36)	0.73 (0.69–0.78)	0.59 (0.53–0.65)
2. Comet-tail artifact	123	0.62 (0.53–0.70)	0.23 (0.15–0.30)	0.78 (0.74–0.81)	0.48 (0.42–0.54)
12/A Is a nodule partially cystic?	123	0.63 (0.54–0.72)	0.50 (0.41–0.59)	0.77 (0.73–0.81)	0.71 (0.66–0.76)
13. Echogenicity of a nodule	123	0.72 (0.68–0.76)	0.24 (0.19–0.29)	0.81 (0.79–0.84)	0.53 (0.49–0.58)
13/A hyper/isoechogenic vs hypoechogenic nodulec	74	0.73 (0.63–0.83)	0.43 (0.29–0.57)	0.79 (0.75–0.83)	0.67 (0.61–0.74)
12. Partially cystic nodule	123	0.79 (0.73–0.85)	0.40 (0.34–0.48)	0.86 (0.83–0.88)	0.67 (0.62–0.72)
15. Extrathyroidal extension	123	0.79 (0.73–0.85)	0.28 (0.15–0.41)	0.87 (0.85–0.90)	0.56 (0.48–0.64)
7. Coarse calcification	123	0.80 (0.73–0.87)	0.46 (0.34–0.57)	0.87 (0.85–0.90)	0.65 (0.59–0.71)
11. Solid vs cystic nodule	123	0.84 (0.79–0.89)	0.50 (0.44–0.58)	0.90 (0.87–0.92)	0.66 (0.61–0.70)
8. Central intranodular coarse calcification	123	0.86 (0.81–0.91)	0.40 (0.28–0.52)	0.92 (0.89–0.94)	0.62 (0.55–0.69)
10. Peripheral (rim) calcification	123	0.92 (0.89–0.95)	0.21 (0.13–0.29)	0.95 (0.94–0.96)	0.45 (0.38–0.52)
1. Nodule or not nodule	123	0.94 (0.91–0.97)	0.12 (0.02–0.22)	0.97 (0.96–0.98)	0.62 (0.47–0.77)
9. Isolated macrocalcification occupying the entire nodule	123	0.98 (0.97–0.99)	−0.01 (−0.02–0.00)	0.98 (0.97–0.99)	0.26 (0.09–0.43)

^aCalculation 13/B was performed for responses to Question 13 which found any degree of hypoechogenicity; ^bCalculation 12/B was performed for ‘yes’ responses to Question 12; ^cCalculation 13/A was performed using the respective responses to Question 13.