Table 1. Comparison of manual and semi-automated scoring of Ki-67 expression.

Criteria	Manual scoring n=33	Semi-automated scoring n=179
		Whole slide scoring	Hot spot scoring	Invasive edge scoring
Intra-observer intra-class correlation coefficient	0.91	0.96	0.96	0.75
Inter-observer intra-class correlation coefficient	0.92	0.92	0.91	0.87
Percentage of slides possible to score in cohort	100	100	100	50
Time per slide (min)	7.7	3.1 (+2 min to run solution)	2.3 (+2 min to run solution)	2.2 (+2 min to run solution)

Invasive edge scoring had lower intra- and inter-observer reproducibility than manual, whole slide or hot spot scoring and could only be performed on the 50% of available slides in which the endometrial–myometrial interface was sampled. Manual scoring had ‘almost perfect' intra- and inter-observer reproducibility but took considerably longer to perform than whole slide and hot spot scoring using the Definiens Developer algorithm.