Pusher syndrome: Reliability, validity and sensitivity to change of a classification instrument

Abstract

Stroke patients with "pusher syndrome" actively push away from the non-paretic side, leading to postural imbalance. The Clinical Scale for Contraversive Pushing (SCP) is the only known instrument developed to evaluate the degree of pushing, but its reliability and validity has not been evaluated. A pilot study of the Swedish version showed that the instrument needed modification. The main purpose of this study was to investigate the interrater reliability and validity of the modified SCP. In addition, the purpose was to determine the change in pushing and functional ability during the acute rehabilitation period. Nineteen consecutive patients exhibiting pushing after stroke were tested before and after the rehabilitation. Berg's Balance Scale and S-COVS were used to study concurrent validity and functional ability. Interrater reliability was measured using Kappa and Spearman's rho. The kappa value was 0.51 before, 0.73 after, and rs was 0.82/0.94. Concurrent validity as determined by Spearman's rho was rs= -0.52/-0.49 in comparison with Berg's Balance Scale and rs= -0.43/-0.45 regarding S-COVS. Degree of pushing and S-COVS improved significantly during the rehabilitation period. The study suggests that the modified SCP has a moderate to good interrater reliability and is sensitive to changes, but further studies are needed to evaluate the prognostic value.