Observer Performance in the Use of Digital and Optical Microscopy for the Interpretation of Tissue-Based Biomarkers

Table 6

Comparison of overall interobserver agreement for the assessment of Ki-67 between the optical microscope and digital environment, using the percent correct agreement metric, as well as category-specific percent correct agreement [95% CI].

Interobserver Ki-67	Percent correct
Scoring category	Optical whole slides	Digital whole slides	Difference
All	78.3 [66.0–88.5]	85.4 [75.0–94.5]	−7.2 [−19.5–4.5]
0	54.2 [33.0–73.4]	63.7 [37.7–84.6]	−9.5 [−29.9–11.6]
1+	70.7 [53.1–85.1]	80.6 [66.1–92.6]	−9.9 [−25.7–5.4]
	Optical TMA	Digital TMA	Difference
All	82.4 [74.4–89.2]	80.5 [71.0–88.2]	1.9 [−5.4–10.2]
0+	68.3 [54.5–80.0]	65.2 [50.6–78.3]	3.1 [−8.4–15.2]
1+	72.3 [60.5–82.6]	69.5 [55.5–81.3]	2.8 [−7.5–14.1]