Validation of a Standardized Assessment of Postural Control in Stroke Patients: The Postural Assessment Scale for Stroke Patients (PASS)

Abstract

Background and Purpose —Few clinical tools available for assessment of postural abilities are specifically designed for stroke patients. Most have major floor or ceiling effects, and their metrological properties are not always completely known. Methods —The Postural Assessment Scale for Stroke patients (PASS), adapted from the BL Motor Assessment, was elaborated in concordance with 3 main ideas: (1) the ability to maintain a given posture and to ensure equilibrium in changing position both must be assessed; (2) the scale should be applicable for all patients, even those with very poor postural performance; and (3) it should contain items with increasing difficulty. This new scale has been validated in 70 patients tested on the 30th and 90th days after stroke onset. Results —Normative data obtained in 30 age-matched healthy subjects are presented. The PASS meets the following requirements: (1) good construct validity: high correlation with concomitant Functional Independence Measure (FIM) scores ( r =0.73, P =10 −6 ), with lower-limb motricity scores ( r =0.78, P <10 −6 ), and with an instrumental measure of postural stabilization ( r =0.48, P <10 −2 ); (2) excellent predictive validity: high correlation between PASS scores on the 30th day and FIM scores on the 90th day ( r =0.75, P <10 −6 ); (3) high internal consistency (Cronbach α-coefficient=0.95); and (4) high interrater and test-retest reliabilities (average κ=0.88 and 0.72). Conclusions —Our results confirm that the PASS is one of the most valid and reliable clinical assessments of postural control in stroke patients during the first 3 months after stroke.