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. In medicine, it has received the most attention in relation to blood pressure measurement, where it has been shown to cause significant discrepancies in recorded values.1 2 A literature search does not however reveal any reference to digit preference in pathology and this is perhaps surprising, considering the importance of accurate measurement.

In order to establish whether or not digit preference may occur in pathology, our …