The brevity of the NPS makes it useful in clinical and research settings in which assessment burden is a significant issue. However, a number of pain qualities that are common to persons with neuropathic and non-neuropathic pain are not assessed by the NPS. These include “electric,” “tingling” (or “pins and needles”), “radiating,” and “numb” qualities.2,4,5,6,24,36 The work of Bouhassira et al,4,5 in particular, has emphasized the importance of paresthesia as a critical component of neuropathic pain, and that patients can provide reliable and valid ratings of this component of neuropathic pain. Adding items that assess each of these qualities to the NPS should increase its content validity for assessing neuropathic pain. In addition, the utility of the measure could be improved further if it included pain qualities common to other pain conditions,6,36 such as a number of the pain quality domains included in more generic (ie, non–diagnosis-specific) measures (eg, the MPQ-SF).27
These include such qualities as “tender,” “shooting,” “cramping,” “throbbing,” “aching,” and “heavy.” We therefore added 10 descriptors to the NPS to increase its content validity for assessing neuropathic pain
and to make it useful for assessing non-neuropathic pain as well. The specific items added assessed tender, numb, electrical, tingling, radiating, throbbing, aching, shooting, cramping, and heavy pain qualities. Also, to improve the temporal item of the NPS, we provided more clear descriptions of the 3 temporal classifications of pain that this item was designed to assess. Because the resulting questionnaire could be used to assess both neuropathic and non-neuropathic pain, we removed the word neuropathic from the scale name and called the resulting 20-item measure the Pain Quality Assessment Scale (PQAS)