The Validity and Reliability of Pain Measures for use in Clinical Trials in Adults: Review Paper Written for the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) meeting, April 12-13, 2003

In order to be most useful, clinical trials of pain treatments should use measures that are both reliable and valid. The purpose of this paper is to summarize the evidence concerning the validity and reliability of pain measures that can be used in clinical trials of pain treatments. The results of this review indicate that commonly used single-item ratings of pain intensity are all valid and adequately reliable as measures of pain intensity, although some scales appear to be easier for patients to understand and use than others. There is less research examining the psychometric properties of measures of pain dimensions other than pain intensity, such as pain relief, the temporal aspects of pain, and pain quality (including pain affect). This lack of evidence limits the conclusions that may be drawn concerning the reliability and validity of these other measures for use in clinical trials. The discussion includes specific recommendations for selecting from among the available pain measures, as well as recommendations for future research into the pain assessment for clinical trials.