Surprisingly poor correlation among pain scores prior to total hip arthroplasty

Pain is the main indication for total hip arthroplasty but is a subjective experience and can therefore be difficult to assess. Using completed forms from six hundred consecutive patients who were to undergo a total hip arthroplasty, we investigated the level of correlation between three widely used pain rating scales. These are: visual analogue pain scale, Merle d’Aubigne pain score and the first question on the Oxford Hip Score. We demonstrate here that there is a surprisingly poor correlation between the scores obtained from the three rating scales, albeit statistically significant. The use of more than one of the above pain scores is indicated due to the slightly different ways in which they ask the patients about their pain experience. This undoubtedly contributes to the modest correlation levels observed. Drawing extensive conclusions from a single pain rating scale may have significant clinical implications