The Pain Quality Assessment Scale: Assessment of pain quality in carpal tunnel syndrome

The Neuropathic Pain Scale (NPS) is a valid measure of the pain qualities and perceived depth of neuropathic pain. However, it does not include a number of pain qualities commonly seen in some neuropathic and non-neuropathic pain conditions. To address this limitation, additional items were added to the NPS to create a 20-item measure (Pain Quality Assessment Scale, PQAS) that would be even more useful for assessing neuropathic pain and also would be used to assess pain qualities associated with non-neuropathic pain. To evaluate the responsivity of the PQAS items to pain treatment, secondary analyses were conducted on data from a trial that compared the efficacy of lidocaine patch 5% versus a single steroid injection in 40 patients with carpal tunnel syndrome. Statistically significant (P <.0025) decreases in 10 of the 20 PQAS pain descriptor ratings occurred with both treatments, and 8 ratings showed nonsignificant trends (.0025 < P <.05) for decreasing before treatment to after treatment. No significant differences were found between the 2 treatment conditions on any of the items. The results support the validity of the PQAS items for assessing the effects of pain treatment on pain qualities of carpal tunnel syndrome. Perspective: Clinical trials that include measures of pain qualities can be used to identify the effects of treatments on distinct pain qualities. Measures such as the PQAS can potentially be used to help clinicians target analgesics more efficiently. (C) 2006 by the American Pain Society.