Non-linear formulas for the spinal cord injury ability realization measurement index.

STUDY DESIGN: The spinal cord injury ability realization measurement index (SCI-ARMI) assesses rehabilitation potential and efficacy based on the linear relationship between the Spinal Cord Independence Measure (SCIM) and the American Spinal Injury Association impairment scale (AIS) motor scores (AMS). OBJECTIVES: The objective of this study is to develop new SCI-ARMI formulas using a more flexible approach that is less sensitive to the distribution of the AMS score among spinal cord lesion (SCL) patients. SETTING: Loewenstein Rehabilitation Hospital, Raanana, and the Statistical Laboratory, School of Mathematics, Faculty of Exact Sciences, Tel-Aviv University, Israel. METHODS: SCIM III and AMS of 226 Israeli SCL patients were monitored. Linear formulas, quadratic formulas and non-parametric formulas were estimated to express the relationship between the 95th percentile of the SCIM III values for patients with given AMS at discharge from rehabilitation (SCIM95) and the corresponding AMS value. This relationship was used to calculate SCI-ARMI values, defined as the ratio of the observed SCIM score and the respective SCIM95 for a given patient's AMS score. RESULTS: The estimated quadratic formula for the relationship between the 95th percentile of the SCIM III and the AMS score was found to be most appropriate, and formulas are provided for SCIM95 calculation in the various areas of function. The use of these formulas to calculate SCI-ARMI values is presented. CONCLUSION: The new formulas improve the accuracy of calculated ability realization for any AMS. The new statistical procedure will be used for the upcoming data analysis of a larger-scale international SCI-ARMI study.

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.