Instrument Precision Study for Validation of Philips Dx

Slides were selected that contained clinically relevant histopathologic "features" that are generally encountered on surgical pathology slides. Twenty-one features, each selected from three different organs, were to be included to ensure that multiple tissue types were investigated. The study feature(s) as selected on each slide was defined as the "selected feature". In total 420 selected features were acquired and the slides holding these features composed the "slide set". The slideset consisted of 399 slides from 399 different participants.

1. Intra-system study. The full slide set was then divided over three subsets. Each subset was then scanned three times on one systems, with each subset being scanned on a different scanner. This means that each feature was scanned three times. Each of three pathologists read all three scans of the entire slide set. Intra-system precision was thereby determined.
2. Inter-system study. The full slide set was then scanned three times, each time on a different system, meaning that each feature was scanned three times. Each of three pathologists (different pathologists the ones used in the intra-system study) read all three scans of the entire slide set. Inter-system precision was thereby determined.