Reliable and valid measures of pain intensity are required for the evaluation of the efficacy of pain treatments with accuracy. But, the most regularly used pain intensity scales like Numerical Rating Scales (NRSs), Visual Analog Scales, and Verbal Rating Scales (VRSs)-are considered to measure mainly pain intensity or the magnitude of felt pain, with an exception of faces pain intensity scales which is thought to measure both pain intensity and pain affect. But these assumption has not been directly tested for VRSs.

A study was conducted to assess whether VRS pain severity ratings are affected by factors like pain beliefs, catastrophizing, or pain interference over and above any effects of pain intensity as measured by NRS. The study was conducted in 4 samples of individuals with physical disabilities and chronic pain.

The results showed that the higher scores on factors describing pain interference with function, pain catastrophizing, and some pain-related beliefs were all linked with a trend for the study individuals to consider their pain as more severe on a VRS.

The findings of this study suggest that VRSs of pain severity cannot certainly be considered to measure only pain intensity, but they may also speculate patient thoughts about pain interference and pain beliefs. Clinicians and researchers should consider these findings while choosing measures and evaluating the results of studies with use of VRSs as outcome measures.