Development and validation of the Neuropathic Pain Symptom Inventory

TLDR

This study develops and validates the Neuropathic Pain Symptom Inventory (NPSI), a self‑questionnaire designed to evaluate the distinct symptoms of neuropathic pain. The NPSI was constructed through a development phase and pilot study that generated descriptors for spontaneous, evoked, and dysesthetic pain, each scored on a 0–10 scale, and validated in 176 patients across five centers by assessing test‑retest reliability, factorial structure, convergent/divergent validity, and sensitivity to treatment changes. The final NPSI, comprising ten descriptors plus two temporal items, discriminates five clinically relevant neuropathic pain dimensions, demonstrates robust psychometric properties, and can identify patient subgroups that respond differently to therapies.

Abstract

This study describes the development and validation of the Neuropathic Pain Symptom Inventory (NPSI), a new self-questionnaire specifically designed to evaluate the different symptoms of neuropathic pain. Following a development phase and a pilot study, we generated a list of descriptors reflecting spontaneous ongoing or paroxysmal pain, evoked pain (i.e. mechanical and thermal allodynia/hyperalgesia) and dysesthesia/paresthesia. Each of these items was quantified on a (0-10) numerical scale. The validation procedure was performed in 176 consecutive patients with neuropathic pain of peripheral (n = 120) or central (n = 56) origin, recruited in five pain centers in France and Belgium. It included: (i) assessment of the test-retest reliability of each item, (ii) determination of the factorial structure of the questionnaire and analysis of convergent and divergent validities (i.e. construct validity), and (iii) evaluation of the ability of the NPSI to detect the effects of treatment (i.e. sensitivity to change). The final version of the NPSI includes 10 descriptors (plus two temporal items) that allow discrimination and quantification of five distinct clinically relevant dimensions of neuropathic pain syndromes and that are sensitive to treatment. The psychometric properties of the NPSI suggest that it might be used to characterize subgroups of neuropathic pain patients and verify whether they respond differentially to various pharmacological agents or other therapeutic interventions.