Differences in the assessment of postoperative pain when evaluated by patients and doctors

This study was undertaken to compare the assessment of pain intensity by 59 patients and by their doctors according to a visual analogue scale (VAS) at rest and when coughing at 5 and 20 hr after major abdominal surgery. The rating given by the patients, who received epidural analgesia to relieve postoperative pain, was significantly above, and moreover, significantly correlated with that given by the doctors at any time or under any condition of the assessment. However, the correlation between the ratings given by patients and doctors at rest at 5 hr after surgery was low (r = 0.39, rs = 0.38) and significantly different from that when coughing at 20 hr after the operation (r = 0.79, rs = 0.80). Our findings indicate that the assessment of postoperative pain may be associated with some unreliability, especially during early periods, when using the subjective or objective-rated VAS at rest separately, and thus requires the combined use or the concomitant use of the VAS when coughing. Substitutional use of the objective-rated VAS for the subjective-rated VAS is not advised.