Scale for contraversive pushing in stroke patients: pusher behavior vs Thalamic astasia differential diagnosis and psychometric properties.

Background: : Few studies have investigated the psychometric properties of the Scale for Contraversive Pushing (SCP) in depth, and none have evaluated its ability to establish differential diagnosis between pusher behavior (PB) and thalamic astasia (TA).

Objectives: : To study the ability of the SCP to establish differential diagnosis, its reliability, content, construct, and internal validity in the assessment of subacute stroke patients.

Methods: : 120 individuals were evaluated using the SCP over a four-week period of treatment. Intra- and inter-observer reliability, floor and ceiling effects, minimum detectable change (MDC), internal validity and sensitivity to change were explored. In addition, the Barthel Index and the Trunk Control Test were used to study their correlations with the SCP.

Results: : Discriminant validity provides evidence that the correlation between SCP items was large or moderate. Convergent validity demonstrated that the correlation of each item with the total score of the scale was high (at around 0.8). Sensitivity to change was large (W = 0.274). Intra- and inter-observer reliability were excellent (Intraclass Correlation Coefficient > 0.9; k > 0.8), except for items B standing and C sitting (k > 0.7). The MDC was 1.39, and ceiling (8.333%) and floor (15.833%) effects were adequate. Cronbach's alpha (α) was equal to 0.901 (0.874-0.924) and McDonald's Omega (ω) was equal to 0.883 (0.856-0.973), showing excellent internal consistency.

Conclusions: : The SCP is a reliable and valid tool which can successfully establish differential diagnosis between PB and TA and evaluate the changes generated by physiotherapy treatment.