The meaning of pain relief in a clinical trial

Data from 207 subjects in the early postoperative period in a controlled clinical trial were used to examine the factors that contribute to global ratings of satisfaction with pain relief. Prerecovery to postrecovery period change scores in pain intensity were not significantly associated with level of satisfaction with pain relief. However, endpoint pain intensity, average pain intensity, recall rating of maximum pain, and actual maximum pain during the immediate postoperative period all predicted relief satisfaction. Of these predictors, average pain and change in pain were associated with relief satisfaction when controlling for all the predictors. The average pain levels reported by patients who rated themselves as being "very satisfied" and "somewhat satisfied" with the level of pain relief were 32.86 (on a 0 to 100 visual analogue scale [VAS]) and 40.00, respectively. Patients who were "slightly satisfied," "neither satisfied nor dissatisfied," and "slightly," "somewhat," and "very dissatisfied" reported similar levels of average pain during the recovery period (range = 51.37-56.32). The findings indicate that the primary variable related to relief satisfaction following surgery during the immediate postoperative period is an average of the pain intensity experienced during this time period.

In order to be "very satisfied" with pain relief during the postoperative period, patients are not required to experience no pain. Rather, the study findings suggest that mild pain averaging less than 40 on a 0 to 100 VAS is adequate. However, moderate pain during the early recovery period averaging about 50 or more on a 0 to 100 VAS appears to be associated with dissatisfaction with pain relief.