Turkish version of the painDETECT questionnaire in the assessment of neuropathic pain: a validity and reliability study

Objectives: The aim of this study was to develop a Turkish version of the painDETECT questionnaire (PD-Q) and assess its reliability and validity.

Methods: Two hundred and forty patients who were diagnosed by expert pain physicians in daily clinical practice and classified as having either neuropathic, nociceptive, or mixed pain for at least 3 months were enrolled in this study. After the usual translation process, the Turkish version of the PD-Q was administered to each participant twice with an interval of 48 hours. The Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), Douleur Neuropathique en 4 questions (DN4) and a pain visual analog scale were assessed along with the PD-Q. Chronbach's α was calculated to evaluate internal consistency of the PD-Q. Intraclass correlation coefficient was calculated to examine test-retest reliability. Convergent validity was assessed by correlating the scale with LANSS and DN4. Discriminant statistics-sensitivity, specificity, Youden index, positive predictive value, negative predictive value-were also assessed.

Results: A total of 240 patients with chronic pain, 80 patients in each neuropathic, nociceptive, and mixed pain group, were included in this study. Mean age of the patients was 54.1 years, and majority of the patients were female (52.9%). Chronbach's α of the Turkish version of the PD-Q was 0.81. The test-retest reliability of the Turkish version of the PD-Q was determined as 0.98 for the total score and ranged from 0.86 to 0.99 for individual items. The Turkish version of the PD-Q was possitively and significantly corralated with LANSS (r 0.89, P < 0.001) and DN4 (r 0.82, P < 0.001). When the two cutoff values in the original version were used, sensitivity was found 77.5% for a cutoff value ≤19, and specificity was 82.5%. Sensitivity and specificity were 90% and 67.5%, respectively, for the other cutoff value ≤12. Scores ≤12 represents a negative predictive value = 87%, and scores 19≤ represents a positive predictive value = 82%. When mixed pain patients were included in the neuropathic pain group, discriminant values were reduced as expected.

Conclusions: The Turkish version of the PD-Q is a reliable and valid scale to be used to determine neuropathic component of chronic pain in Turkish patients.