Scale for Contraversive Pushing: Cutoff Scores for Diagnosing “Pusher Behavior” and Construct Validity

Abstract

Background and Purpose Considerable disagreement exists among researchers with regard to the prevalence, pathophysiology, and treatment of “pusher behavior” (PB), partly because of different testing procedures. This study was primarily aimed at establishing cutoff scores for and the construct validity of the Scale for Contraversive Pushing (SCP). The prevalence of PB in people with right- and left-brain lesions also was investigated. Subjects and Methods The study subjects were 105 consecutive patients with recent stroke. Two methods were used to diagnose PB: clinical examination and SCP score with 3 different cutoff points—an SCP total score of greater than 0 (Crit_1), subscores in each section of the scale of greater than 0 (Crit_2), and subscores in each section of the scale of ≥1 (Crit_3). Clinical and SCP diagnoses were independently made by different examiners. The Cohen κ coefficient was used to determine the agreement between clinical and SCP diagnoses. The construct validity of the SCP was estimated by calculation of Spearman rank correlation coefficients for SCP and balance, mobility, and functional scores. Results The agreement between clinical and SCP diagnoses was low (κ=.212) when Crit_1 was used. Crit_2 led to the highest agreement with the clinical diagnosis (κ=.933). However, only Crit_3, although globally less accurate (κ=.754), ensured no false-positive results. The construct validity of the SCP was demonstrated by significant (P<.001) moderate to high correlations with mobility (rho=.595), functional (rho=.632), and balance (rho=.666) scores. The prevalence of PB was not influenced by the side of the lesion. A limitation of the study was that the reliability of the clinical examination method was not investigated. Discussion and Conclusion The results support the validity of the SCP and suggest the need to choose different SCP cutoff criteria (Crit_2 or Crit_3) according to the aim of the evaluation.