The significance of pain catastrophizing in clinical manifestations of patients with lumbar spinal stenosis: mediation analysis

BACKGROUND CONTEXT: Pain intensity in various chronic pain disorders has been associated with catastrophizing. Considering the pathomechanism and clinical symptoms of lumbar spinal stenosis (LSS), pain catastrophizing could be associated with pain intensity and disability in patients with LSS. PURPOSE: Firstly, to determine whether catastrophizing is associated with an increased intensity of pain and disability, and secondly, to determine whether it is linked to the relationship of gender to pain and disability in patients with degenerative LSS by using mediation analyses with bootstrapping. STUDY DESIGN: Medical records review. PATIENT SAMPLE: Patients with degenerative LSS were included. OUTCOME MEASURES: They included visual analog scale (VAS) for back pain, VAS for leg pain, Oswestry Disability Index (ODI), and pain catastrophizing scale (PCS). METHODS: Ninety-five patients who were diagnosed with degenerative LSS were included in this study. Detailed demographic data including age, sex, and body mass index and series of questionnaires were collected, including PCS, ODI, and VAS for back and leg pain. Radiologic analysis including the grade of canal stenosis and disc/facet joint degeneration was performed using magnetic resonance imaging and computed tomography findings. After adjustment of covariates, multivariate regression analysis was used to assess each component of the proposed mediation models among VAS for back/leg pain, ODI, gender, and PCS. Mediation was also assessed by the bootstrapping technique. RESULTS: Pain catastrophizing demonstrated a significant positive association with pain intensity and disability represented by VAS for back and leg pain and ODI scores. The mediation analysis confirmed the mediating role of VAS for back pain in the relationship between PCS and ODI. Furthermore, multivariate regression analysis with bootstrapping demonstrated that the PCS significantly mediated the gender differences in VAS for back pain and ODI. CONCLUSIONS: Pain catastrophizing was amediator of gender differences for back pain and disability in patients with LSS. In addition, pain catastrophizing was associated with disability in LSS, which was partially mediated by increased back pain intensity. (C) 2015 Elsevier Inc. All rights reserved.