Is there significant correlation between self-reported low back pain visual analogue scores and low back pain scores determined by pressure pain induction matching?

The objective of this study was to determine whether self-reported visual analogue scale (VAS) low back pain (LBP) scores are valid against matched psychophysically induced pressure pain scores. Two hundred thirty-six chronic LBP patients (some with neck pain) reported their LBP and neck pain scores on a VAS immediately before psychophysical pressure pain induction used to determine pain threshold (PTHRE), pain tolerance (PTOL), and a psychophysical pressure pain score which matched (PMAT) their current LBP. Pearson Product-Moment correlation coefficients were calculated between reported VAS neck scores, reported VAS LBP scores, and the psychophysically determined LBP PMAT scores. The PMAT scores were calculated utilizing PTOL only and both PTOL and PTHRE. There was a significant correlation between the LBP PMAT scores and the reported LBP VAS scores for both types of psychophysical LBP PMAT score calculations; however, there were insignificant correlations between the LBP PMAT scores and reported neck VAS scores. Chronic LBP patients can match their self-reported VAS LBP scores to psychophysically determined LBP PMAT scores. As such, self-reported VAS chronic LBP scores appear to be valid against one type of psychophysical measurement.