The Associated Factors of Neuropathic Pain Among Chronic Low Back Pain Patients in South Korea: Findings from the NLBP OR

Abstract

Low back pain (LBP) patients with neuropathic pain (NP) had substantially impaired quality of life. We investigated possible factors associated with NP in chronic LBP patients. Data were extracted from the NLBP OR [the NP in chronic LBP patients; Korean epidemiological study]. It was a multicenter and cross-sectional study where 1,200 patients older than 20 years of age with chronic LBP longer than 3 months, with a visual analog scale (VAS) pain score higher than 4, and with pain medication at least 4 weeks prior to enrollment were recruited at 27 general hospitals from December 2014 to May 2015. Potential factors related to NP were age, sex, LBP duration from diagnosis, Quebec Task Force Classification for Spinal Disorders (QTFC-SD), comorbidities, and pain VAS and were collected by medical chart review. Douleur Neuropathique 4 (DN4) was used for diagnosis of NP (DN4≥4). Analysis was performed on 880 patients (mean age 64 years, male 34%) who had complete data of all measured variables. 362 (41%; mean age 63 years, male 40%) patients were classified as NP. In multiple logistic regression analysis, independently associated factors of NP prevalence were male (adjusted odds ratio, 1.7; 95% Confidence Interval, 1.2-2.3) and having pain of severe intensity compared to moderate pain (1.8; 1.4-2.4). In addition, compared to pain without radiation, pain with proximal extremity radiation (3.5; 1.8-6.8), pain with distal extremity radiation (7.4; 4.1-13.6), pain with radiation and neurologic finding (7.6; 3.6-16.3), spinal nerve root compression (5.9; 2.8-12.4), and spinal stenosis (4.6; 2.3-9.2) were respectively associated with NP prevalence. When physicians treat chronic LBP, more attention should be given to those patients with related factors of NP.