LAUSR

Michael Rosen’s 1976 paper on the reliability of the linear analogue for evaluating pain – now more commonly called a visual analogue scale (VAS) – starts with the words: “pain is difficult to measure” [1]. This is as true now as it was 45 years ago and is likely to remain true for some years to come. The title might be taken to imply that the study on which the paper is based assessed the validity of the VAS as a method for objectively assessing pain, but this is far from its purpose. Rather, the publication of this paper showed the VAS to be a reliable and repeatable assessment tool of a patient’s selfreport of their pain and, in doing so, gave academics a way of measuring and comparing the effects of analgesic regimens on acute pain and clinicians the ability to assess and track the efficacy of painmanagement.