Reliability of the revised wheelchair rugby trunk impairment classification system

Study design: Observational, cross-sectional. Objectives: A new classification system for trunk impairment in wheelchair rugby was introduced in 2010. It consists of 10 tests, arranged in an algorithm, to assign four different trunk scores (0, 0.5, 1.0 or 1.5) to athletes. The purpose of this study was to assess the inter-rater reliability of this classification system. Setting: National competition for wheelchair rugby and wheelchair basketball in the Netherlands and Belgium. Methods: Three experienced wheelchair rugby classifiers independently assigned trunk scores to wheelchair rugby and wheelchair basketball athletes in two sessions. After each session, test descriptions were adjusted. The inter-rater reliability was evaluated by determining the agreement and Fleiss Kappa. Results: In the first session, all classifiers agreed on the trunk score in 13 out of 16 athletes; the overall Kappa was 0.76 (P < 0.001). The Kappa per trunk score ranged from 0.29 to 1. Four test descriptions were adjusted after the first session. In the second session, there was an agreement in trunk score between the classifiers in 15 out of 21 athletes. The overall Kappa was 0.75 (P < 0.0001), and the Kappa per trunk scores ranged from 0.58 to 0.92. After the second session, two test descriptions were improved. Conclusion: The revised classification system for trunk impairment in wheelchair rugby showed a adequate inter-rater reliability for the allocation of trunk scores.