Evaluation Of Three Neuropathic Pain Screening Scales In Patients With Axial Spondyloarthritis

BackgroundPain relief is one of the main treatment goals of patients with Axial Spondyloarthritis(axSpA),while first line treatment drugs of axSpA such as biological agents are not effective in alleviating neuropathic pain(NP).The screening of NP could promote pain management.There is no gold standard for diagnosis of NP in patients with axSpA,and scales are important tools for NP screening.However,the reliability,validity,and applicability of the current available NP scales in patients with axSpA are lacking.ObjectivesTo evaluate the reliability,validity,and applicability of painDETECT Questionnaire,Leeds Assessment of Neuropathic Symptoms and Signs,and Douleur Neuropathique 4 Questionnaire in patients with axSpA.Methods1.ParticipantsA total of 186 patients with axSpA admitted to Department of Rheumatology and Immunology of a Grade Ⅲ hospital in Guangzhou from October 2020 to October 2021 were recruited.2.Instruments2.1 painDETECT Questionnaire(PD-Q):It consists of four main sections.The first section assess intensity of pain at the moment,the average and the maximum pain intensity during the past 4 weeks.In the second.section,patients describe pain course patterns.The third section includes pain zone and the direction of radiating pain.The fourth part includes the paresthesia and pain sensation.The total points is 38.The cutoff value of the Chinese version of the PD-Q≥13 indicates the presence of neuropathic pain component.2.2 Leeds Assessment of Neuropathic Symptoms and Signs(LANSS):It contains five symptoms and two clinical examination items.The first part consist five dichotomous items asking the patient about the kind of pain experienced in the last week.In the second part,presence of allodynia and altered pinprick perception threshold are explored by health care professional.Each item is marked as present or absent,and the presence of each sign has different score.The possible scores range from 0 to 24,with a score of 12 or greater suggests neuropathic pain.2.3 The Douleur Neuropathique 4 Questionnaire(DN4):It contains seven items related to symptoms and three related to clinical examination.A score of 1 is given to each positive item and a score of 0 to each negative item.The total score is calculated as the sum of the 10 items,and score of≥ 4 states suggests NP.3.ProcedureAfter modifying the Chinese translation of several items using Brislin back-translation method,we conducted a pilot study of the Chinese version of the three scales in 30 patients with axSpA to ensure clarity and cross-cultural equivalence.Then the main study was conducted to evaluate the psychometric properties of the three scales.All participants signed informed consent.Data was collected in the clinic and ward of the Rheumatology and Immunology.Participants completed the above three scales.Demographic and clinical characteristics were collected via electronic medical records.At the completion of data collection,participants were also asked to identify the scale they preferred.4.Statistical analysisSPSS 25.0 statistical software was used to analyze data.The reliability is expressed by Cronbach’s α coefficient and Guttman split-half coefficient,respectively.Structural validity was calculated by factor analysis.Aggregate validity was expressed by correlation between scale items,dimensions and total scores.Consistency and correlation between scale results were represented by Kappa and correlation coefficient r,respectively.Results1.The reliability of the scalesThe Cronbach’s α coefficient of the PD-Q was 0.807,and the Guttman split-half coefficient was 0.846.The Cronbach’s α coefficient of the LANSS was 0.623,and the Guttman split-half coefficient was 0.701.The Cronbach’s α coefficient of the DN4 was 0.697,and the Guttman split-half coefficient was 0.691.2.The validity of the scalesTwo main factors were extracted from the original nine factors of the PD-Q,and the total cumulative variance contribution rate was 55.171%.Two main factors were extracted from the original seven factors of the LANSS,and the total cumulative variance contribution rate was 50.836%.Four main factors were extracted from the original ten factors,and the total cumulative variance contribution rate was 63.627%.3.The consistency,correlation and scale preferenceThe Kappa value and correlation coefficient between the LANSS and the DN4 are 0.504 and 0.532,P<0.01.The Kappa value and correlation coefficient between the LANSS and the PD-Q are 0.529 and 0.534,P<0.01.The Kappa value and correlation coefficient between the DN4 and the PD-Q are 0.582 and 0.593,P<0.01.The preference rate of the PD-Q,the LANSS and the DN4 in patients with axSpA were 71.5%,14.0%and 3.2%.ConclusionThe PD-Q has good reliability and validity.The LANSS and the DN4 have fair reliability and good validity.The three NP scales have strong consistency and correlation.The PD-Q has highest patients preference rate.