Assessing pain in multiple sclerosis: Test-retest reliability of patient-reported outcome measures and accuracy of screening tools

Abstract

Background: Pain is a common symptom of multiple sclerosis (MS). The reliability of outcome measures for pain and the accuracy of screening tools are essential for treatment purposes.Objectives: This study investigated the test-retest reliability of Neuropathic Pain Scale (NPS), Neuropathic Pain Symptom Inventory (NPSI), Brief Pain Inventory-Short Form (BPI-SF), Nordic Musculoskeletal Questionnaire (NMQ), Douleur Neuropathique 4 (DN4), and painDETECT, and the accuracy of DN4 and painDETECT.Methods: 110 persons with MS were included (mean age: 45.35 +/- 12.73; Expanded Disability Status Scale (EDSS): 3 (Interquartile range, IQR: 2.6)). The reliability (internal consistency, test-retest, measurement error) and accuracy (area under the curve (AUC), specificity, sensitivity, positive predictive value, and negative predictive value) were analyzed.Results: All included pain assessment tools showed good test-retest reliability (Intraclass correlation coefficient, ICC, (95% confidence interval, CI): 0.85 (0.79-0.89)-0.89 (0.84-0.92)) and good-to-excellent internal consistency (Cronbach's alpha: 0.73-0.93). The test-retest reliability of NMQ was moderate to substantial (Cohen's kappa = 0.54-0.87). The overall accuracy of DN4 compared to the neurologist's diagnosis was acceptable (AUC = 0.762), while that of painDETECT was poor (AUC = 0.682) and demonstrated inadequate predictive ability.Conclusion: All pain outcome measures were reliable in patients with MS (pwMS). DN4 can be used to screen neuropathic pain in MS.Clinical trial registry name: Reliability and Validity of Outcome Measures for Pain in MS https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000CRMD&selectaction=Edit&uid=U0006NAA&ts=2&cx=-jzvd6m Registration number: NCT05742152