Value of the central sensitisation inventory in patients with axial spondyloarthritis

Background In many patients with axial spondyloarthritis (axSpA), pain persists despite anti-inflammatory medication. Quantitative sensory testing (QST) indirectly assesses altered somatosensory function, though its clinical practicality is limited. The Central Sensitisation Inventory (CSI) could be an alternative in the initial assessment of central sensitisation (CS). This study aimed to investigate the value of the CSI in evaluating CS in patients with axSpA by (1) assessing somatosensory function related to CS with QST and (2) exploring associations between CSI, QST, patient and disease characteristics and pain-related psychosocial factors.Methods Consecutive outpatients from the Groningen Leeuwarden AxSpA cohort underwent QST, including pressure pain threshold (PPT), temporal summation (TS) and conditioned pain modulation (CPM). Participants completed questionnaires assessing CS (CSI), illness perception (Revised Illness Perception Questionnaire, IPQ-R), pain-related worrying (Pain Catastrophising Scale, PCS), fatigue (Modified Fatigue Impact Scale, MFIS), anxiety/depression (Hospital Anxiety and Depression Scale, HADS) and coping. QST measurements were stratified for CSI≥40.Results 201 patients with axSpA were included; 63% male, 64% radiographic axSpA, median symptom duration 12 years (IQR 5–24), mean Axial Spondyloarthritis Disease Activity Score 2.1±1.0. Patients with CSI≥40 had significantly lower PPTs and higher TS than CSI