Validation analysis of Polish version of Neuropathic Pain Questionnaire - Short Form (NPQ-SF-PL) and assessment of quality of life in patients with chronic neuropathic pain.

Aim of the study: The aims of this study were to translate and culturally adapt the Polish version (PL) of the Neuropathic Pain Questionnaire-Short Form (NPQ-SF), as well as to compare this questionnaire to other diagnostic tools in terms of reliability and psychometric validity.

Clinical rationale for the study: Neuropathic pain (NP) affects up to 10% of the general population. Despite a large number of studies, almost 50% of patients have a poor therapeutic outcome. Diagnostic tools are intended to distinguish between NP and non-NP (NoP) and to guide the examiner to perform further diagnostics in accordance with the guidelines.

Material and methods: A total of 140 patients with chronic pain (ChP), 90 with NP and 50 with NoP, were enrolled into this study. NPQ-SF-PL has been developed following the guidelines for translation and cultural adaptation. Reliability of the translated version was examined using internal consistency, predictive validity, and intraclass correlation coefficient (ICC).

Results: In the study, women predominated over men, and the average age was 53.22. Cronbach's α value for the entire scale was 0.76 and ICC for test-retest reliability was 0.631. Receiver-operating characteristic curve analysis gave a sensitivity of 90.0% and a specificity of 88.0%. Area under the curve was 0.94. NPQ-SF-PL was moderately associated with self-completed Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and weakly associated with the Numerical Rating Scale (NRS). The NP group obtained statistically significantly lower scores than the NoP group in all domains of the 36-Item Short Form Health Survey (SF-36), thus indicating worse health status. Patients aged over 41 years presented a worse quality of life compared to younger ones. Also, more than half of the patients with NP of both genders experienced symptoms of mild or more severe depression.

Conclusions: NPQ-SF-PL is a valid screening tool for assessing NP in Polish chronic pain patients. The obtained results showed very good psychometric properties and adequate internal consistency. The repeatability of the questionnaire indicated moderate reliability. Clinical implications/future directions. We believe this study will provide physicians with a new instrument for the evaluation of NP for clinical and research purposes.