A new grading for easy and concise description of functional status after spinal cord lesions

Background: Disability scales do not enable the transmission of concise, meaningful and daily function description for clinical purposes. Study design: Cross-sectional statistical analysis of 328 patients' Spinal Cord Independence Measure (SCIM) III item scores (SIS). Objective: To develop a concise and clinically interpretable data-based characterization of daily task accomplishment for patients with spinal cord lesions (SCLs). Setting: Multi-center study at 13 spinal units in 6 countries. Methods: Patients were grouped into clusters characterized by smaller differences between the patients' SIS within the clusters than between their centers, using the k-medoides algorithm. The number of clusters (k) was chosen according to the percent of SIS variation they explained and the clinical distinction between them. Results: Analysis showed that k=8 SIS clusters offer a good description of the patient population. The eight functional clusters were designated as A-H, each cluster (grade) representing a combination of task accomplishments. Higher grades were usually (but not always) associated with patients implementing more difficult tasks. Throughout rehabilitation, the patients' functional grade improved and the distribution of patients with similar functional grades within the total SCIM III score deciles remained stable. Conclusions: A new classification based on SIS clusters enables a concise description of overall functioning and task accomplishment distribution in patients with SCL. A software tool is used to identify the patients' functional grade. Findings support the stability and utility of the grades for characterizing the patients' functional status. Spinal Cord (2012) 50, 42-50; doi:10.1038/sc.2011.84; published online 2 August 2011