Validation of a standardized assessment of postural control in stroke patients - The Postural Assessment Scale for Stroke patients (PASS)

Background and Purpose-Few clinical tools available for assessment of postu ral abilities are specifically designed for stroke patients. Most have majo r floor or ceiling effects, and their metrological properties are not alway s completely known. Methods-The Postural Assessment Scale for Stroke patients (PASS), adapted f rom the BL Motor Assessment, was elaborated in concordance with 3 main idea s: (1) the ability to maintain a given posture and to ensure equilibrium in changing position both must be assessed; (2) the scale should be applicabl e for all patients, even those with very poor postural performance; and (3) it should contain items with increasing difficulty. This new scale has bee n validated in 70 patients tested on the 30th and 90th days after stroke on set. Results-Normative data obtained in 30 age-matched healthy subjects are pres ented, The PASS meets the following requirements: (1) good construct validi ty: 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 b etween PASS scores on the 30th day and FIM scores on the 90th day (r = 0.75 , P < 10(-6)); (3) high internal consistency (Cronbach alpha-coefficient = 0.95); and (4) high interrater and test-retest reliabilities (average kappa = 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.