Concurrent validity of pain scales in individuals with myofascial pain and fibromyalgia.

Abstract

Clinicians and researchers often use the numeric pain rating scale (NPRS) and visual analog scale (VAS) to measure and track pain in individuals with myofascial pain syndrome (MPS) and fibromyalgia (FM). The VAS is often used as a reference standard in chronic pain research. To date, no studies have specifically measured the concurrent validity of the NPRS and VAS in these individuals. The purpose of this investigation was to determine the concurrent validity of the NPRS when compared to the reference standard VAS in patients with MPS and FM.