Our review revealed a great heterogeneity in definition , format , and values of what is considered a clinical ly relevant difference in pain in RCTs of analgesics , and st and ardizations are advisable
OBJECTIVE To describe the  pain decrease considered as clinical ly relevant when design ing a trial and reporting its results .
Clinically important changes in acute pain outcome measures: a validation study.
The purpose of this study was to vali date the changes in acute pain measurement scales that are most strongly associated with a patient-determined indicator of clinical importance . Measures of pain intensity and pain relief are commonly used outcomes in therapeutic clinical trials . Recent studies of the properties of acute pain measures have provided data defining the cut-off points that are best associated with clinical ly important differences . Validation of these findings in another clinical trial data set is important . Data were obtained from the titration phase of a recently conducted r and omized controlled clinical trial of oral transmucosal fentanyl citrate ( OTFC ) , which compared OTFC to immediate release morphine sulfate ( MSIR ) for the treatment of cancer-related acute breakthrough pain .  Changes in pain intensity and pain relief were recorded every 15 minutes for 60 minutes and global medication performance recorded at the end of each study pain episode . At any titration step , if the patient felt that the first dose of the study medication did not provide adequate relief within 30 minutes , an additional rescue medication could be taken . To find the level of each pain scale best associated with this measure of the adequacy of pain relief , the calculated sensitivity , specificity , and accuracy for different cut-off points of the measured pain scales were compared to whether or not the patient needed rescue medication . The overall ability of the pain measures to discriminate episodes for which a rescue was not needed was calculated using area under the receiver operating characteristics ( ROC ) curves . Data were analyzed from 134 OTFC-naive patients who collected data on 1307 episodes of breakthrough pain . Using the criteria of a balanced sensitivity and specificity , the best cut-off points were determined to be : 33 % for the percent pain intensity difference ; > or = 2 for the raw pain intensity difference on a 0 - 10 numeric rating scale ; > or = 2 ( i.e. , moderate or better ) for pain relief ; > or = 33 % for the percent maximum total pain relief ; and > or = 2 ( good or better ) for global medication performance . ROC area under the curve ranged from 0.839 to 0.862 for each of the pain measures listed above , calculated at 60 minutes . These data indicate that the pain scale cut-off points that are best associated with a patient-derived measure of a clinical ly important difference closely approximate those found in an earlier study . ROC analysis provided evidence that the overall pain measures were strongly associated with not requiring an " additional dose of rescue medication . " Thus , the cut-off points determined for these pain scales provide a good surrogate measure of a patient-determined clinical ly important response . This provides support for the usefulness of these values in future clinical trials of pain therapy
Our review revealed a great heterogeneity in definition , format , and values of what is considered a clinical ly relevant difference in pain in RCTs of analgesics , and st and ardizations are advisable
OBJECTIVE To describe the  pain decrease considered as clinical ly relevant when design ing a trial and reporting its results .