Inter-rater agreement of a pathophysiology-derived clinical assessment tool for complex regional pain syndrome type I in physiotherapy: an explorative study

Abstract Background Patients with Complex Regional Pain Syndrome Type I (CRPS) typically exhibit highly variable clinical presentations along with significant and prolonged distress. While the role of physiotherapy is considered important, clear evidence-based treatment guidelines are lacking. For development of such in the future, a subgrouping into their underlying pathophysiological mechanisms has been proposed. The aim of this study was to determine the intertester agreement of physiotherapists using a novel clinical assessment tool for patients with CRPS Type I. Methods A total of 20 patients diagnosed with CRPS Type I underwent a clinical sensory test battery, examinations concerning body perception and measurements of vegetative processes. The examination was recorded, rated and evaluated by a total of four raters. The therapists categorized their findings into four distinct categories: peripheral sensitization, central sensitization, cortical reorganization, and vegetative responses. They then estimated the proportions of these categories for each patient. The intertester agreement on the estimations was calculated using the Bhatthacharyya coefficient, involving the assessments of four different therapists. Results The agreement coefficient among all raters, determined through a methodology for analyzing compositional data, ranged from 0.75 to 0.93. Conclusion The multifactorial pathophysiology and its overlap in CRPS pose significant challenges for physiotherapeutic findings and treatments for these patients. In this exploratory study, we have identified good agreement among our findings and gained valuable insights for clinical practice. Furthermore, we hope that our work will aid clinicians in structuring their management approaches for patients with CRPS Type I.