Terminal digit preference is defined as a phenomenon whereby an observer rounds off a measurement to a digit of his or her choosing, commonly the terminal digit zero.1

It has been shown to occur in the reporting of colorectal adenocarcinomas and is thought to represent an under-recognised source of error in pathology reporting.2 In such circumstances, digit preference is unlikely to influence patient management, as minor variations in tumour measurement would not change either the tumour, node, metastases (TNM) or Dukes’ tumour stage.3 Digit preference could therefore occur in the context of colorectal carcinoma reporting, as pathologists may round off measurement values with a prior knowledge that this would have no effect on patient management.

It therefore remains uncertain whether or not digit preference occurs …