The objective of this study was to evaluate the validity and responsiveness of the Spinal Cord Index of Function (SIF), a new instrument on activity level, measuring the ability to perform various transfers in non-walking patients with a spinal cord lesion. Twenty-nine patients with a spinal cord lesion classified as grade A, B or C according to the American Spinal Injury Association/International Medical Society of paraplegia classification were included. Each patient was evaluated from the acute phase until discharge, every second week, by their physiotherapist, according to SIF and the Swedish physiotherapy clinical outcome variables (S-COVS). To determine validity, Spearman’s rho correlation coefficient was calculated between the total scores of SIF and S-COVS, and the determination coefficient was calculated. Responsiveness was determined by computing effect sizes. Spearman’s correlation between SIF and S-COVS was 0.933 and the determination coefficient was 0.87. The effect size for SIF was 9.1.
The results of the study prove that SIF is a valid and sensitive instrument, which will be useful for physiotherapists in goal-planning programs and in evaluating progress during a patient’s rehabilitation. SIF could also be used in research and in evaluating the patient’s functional ability at follow-ups.