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

Table 1

Comparison of overall interobserver agreement for the assessment of HER2 between the optical microscope and digital environment, across TMA and whole slides, using Kendall’s tau- metric [95% CI].

Interobserver HER2	Kendall’s tau- on continuous scores [95% CI]			Kendall’s tau- on categorical scores [95% CI]
	Optical	Digital	Difference	Optical	Digital	Difference
Whole slides	0.75 [0.58–0.87]	0.67 [0.49–0.80]	0.08 [–0.02–0.19]	0.77 [0.61–0.88]	0.69 [0.49–0.80]	0.09 [–0.03–0.21]
TMA	0.80 [0.71–0.86]	0.80 [0.73–0.85]	0.00 [–0.06–0.05]	0.79 [0.71–0.86]	0.83 [0.73–0.85]	–0.04 [–0.11–0.02]