Cross-cultural adaptation and validation of the Persian version of the painDETECT questionnaire

Objective The purpose of this study was to translate and cross-culturally adapt the painDETECT questionnaire into the Persian language and assess the clinometric properties of the translated version (P-PDQ). Methods This is a single-center prospective observational study. After forward and backward translations, consensus was achieved by the expert panel on the pre-final version. Semantic equivalence of this version was assessed and necessary modifications were made accordingly to achieve the final version (P-PDQ). One hundred and fifty chronic pain patients were sub-classified into neuropathic pain (NeP (n = 82)) or non-NeP (n = 68) groups by two pain specialists. P-PDQ was then administered to 50 patients twice with an interval of 5-7 days to assess relative reliability. Chronbach's alpha and intraclass correlation coefficient (ICC) were calculated to evaluate internal consistency and test-retest reliability of the P-PDQ, respectively. Criterion validity was assessed as the correlation of the P-PDQ and the validated Persian version of the self-report Leeds Assessment of Neuropathic Symptoms and Signs (P-sLANSS). Results Chronbach's alpha and ICC of the P-PDQ were 0.76 and 0.97, respectively. The P-PDQ scores were significantly correlated with those of P-sLANSS (rho = 0.87, p < .01). The mean overall score of P-PDQ was significantly higher in the NeP group (p < .01) which reflects discriminant validity. Sensitivity, specificity, positive and negative predicting values and Youden index were 74.70%, 98.51%, 78.04%, 98.48%, and 0.73, respectively at the cutoff value <= 17. Conclusion The P-PDQ is a reliable and valid tool to distinguish neuropathic component in chronic pain cases.