Psychometric validation of the Portuguese version of the Neuropathic Pain Symptoms Inventory
1 Pain Center, Hospital das Clínicas, Department of Neurology of the University of São Paulo, Brazil
2 Instituto do Câncer do Estado de São Paulo Otávio Frias de Oliveira, Brazil
3 Divisão de Neurologia e Epidemiologia, Universidade Federal da Bahia, Brazil
4 Coordenação de Pós-Graduação, Pesquisa e Extensão, Escola Bahiana de Medicina e Saúde Pública, Brazil
5 INSERM U-987, CHU Ambroise Paré, APHP, F-92100 Boulogne-Billancourt, France
Health and Quality of Life Outcomes 2011, 9:107 doi:10.1186/1477-7525-9-107Published: 30 November 2011
It has been shown that different symptoms or symptom combinations of neuropathic pain (NeP) may correspond to different mechanistic backgrounds and respond differently to treatment. The Neuropathic Pain Symptom Inventory (NPSI) is able to detect distinct clusters of symptoms (i.e. dimensions) with a putative common mechanistic background. The present study described the psychometric validation of the Portuguese version (PV) of the NPSI.
Patients were seen in two consecutive visits, three to four weeks apart. They were asked to: (i) rate their mean pain intensity in the last 24 hours on an 11-point (0-10) numerical scale; (ii) complete the PV-NPSI; (iii) provide the list of pain medications and doses currently in use. VAS and Global Impression of Change (GIC) were filled out in the second visit.
PV-NPSI underwent test-retest reliability, factor analysis, analysis of sensitivity to changes between both visits. The PV-NPSI was reliable in this setting, with a good intra-class correlation for all items. The factorial analysis showed that the PV-NPSI inventory assessed different components of neuropathic pain. Five different factors were found. The PV-NPSI was adequate to evaluate patients with neuropathic pain and to detect clusters of NeP symptoms.
The psychometric properties of the PV-NPSI rendered it adequate to evaluate patients with both central and peripheral neuropathic pain syndromes and to detect clusters of NeP symptoms.