[How reliable is our memory for acute postoperative pain]

Clinicians use patients' recall of pain as an important source of evidence both in diagnosis and in assessing improvements following treatment. Yet very little is known about the accuracy of these retrospective accounts up to now.

We examined patients' retrospective evaluations of the pain they experienced at the first postoperative day and related these evaluations to the pain intensity which was recorded in the PCA-report.

We found that recall was moderately accurate. Patients mostly overestimated their pain intensity. We could demonstrate that patients who overestimated their pain differed significantly from those who did not. The patients who overestimated showed no significant pain relief over the first three postoperative days. Other influences were the pain intensity of the third day and patients' expectations of the postoperative pain intensity. Our results could be embedded within the theoretical framework of general memory research.

We conclude that real-time evaluations of pain intensity should be recorded additionally to retrospective accounts. Retrospective ratings are important too, because we suggest that the memory of pain more than the experience of pain itself form the basis of patients' future decisions about treatment including their compliance and their satisfaction with pain management.