Table 3.

Intraobserver concordance of 118 pathologists’ interpretations of melanocytic skin biopsy lesions of the same case at phase 1 and phase 2 at least eight months apart*

Phase 1 diagnosis	Phase 2 diagnosis (No of paired interpretations)						Intraobserver concordance† % (95% CI)
	Class I	Class II	Class III	Class IV	Class V	Total
Class I	1155	188	119	27	17	1506	77 (73 to 80)
Class II	170	227	182	37	28	644	35 (31 to 39)
Class III	91	120	653	169	58	1091	60 (56 to 63)
Class IV	20	37	147	531	105	840	63 (59 to 67)
Class V	14	16	44	105	852	1031	83 (80 to 85)
Total	1450	588	1145	869	1060	5112	67‡ (65 to 69)

Numbers of diagnostic interpretations with intraobserver agreement are emboldened.

*Concordance rates are influenced by case composition, which included larger proportions of cases in classes II-V than would typically be encountered in practice.

†Denominator is phase 1 interpretations and numerator is phase 2 assessments that agreed with phase 1 interpretation. Does not include participants who reviewed glass slides in phase 1 and digital images in phase 2.

‡Average κ for intraobserver agreement across participants is 0.57.