Reliability and Validity of the Four-Point Pusher Score: An Assessment Tool for Measuring Lateropulsion and Pusher Behaviour in Adults after Stroke

Abstract

Purpose: The authors determined the reliability and validity of the Four-Point Pusher Score (4PPS) among stroke survivors. Method: Stroke survivors were invited to participate within 48 hours of admission to a stroke rehabilitation unit in a tertiary hospital. Intrarater reliability was determined by examining scores assigned to the same patient by the same physiotherapist. Interrater reliability was determined by examining scores assigned to the same patient by two other physiotherapists. Validity was determined by examining associations with the Burke Lateropulsion Scale (BLS), Scale for Contraversive Pushing (SCP), and functional scales. Results: A total of 85 participants who were a median of 13 (interquartile range 9–21) days post-stroke completed this study. The weighted κ statistic for 4PPS intra- and interrater reliability was 0.97 ( p < 0.001). Scores on the 4PPS were very strongly associated with scores on the BLS ( rs = 0.95) and the SCP ( rs = 0.86). Strong associations were evident between the 4PPS and the Berg Balance Scale ( rs = –0.77), Chedoke-McMaster Stroke Assessment postural control scale ( rs = –0.76), and FIM Motor sub-scale ( rs = –0.64; all ps < 0.001). Conclusion: The 4PPS is a reliable and valid scale to assess lateropulsion and pusher behaviour in stroke survivors in an in-patient rehabilitation setting.