Background and purpose: The trunk control items of the Postural Assessment Scale for Stroke Patients (PASS-TC) have been proposed for use in examining patients with stroke. The purpose of this study was to examine the discriminative and predictive validities and the evaluative properties of the PASS-TC at 14, 30, 90, and 180 days after stroke onset.
Subjects and methods: A total of 269 patients with stroke participated in this prospective study. The PASS-TC was administered at the 4 time points after stroke onset. The distributions of the PASS-TC scores were used to determine the discriminative ability to distinguish between individuals at the 4 time points. A comprehensive activities of daily living (CADL) measure was administered 1 year after stroke onset as an external criterion for examining the predictive ability of the PASS-TC. Changes in PASS-TC scores between the intervals of 14 to 30, 30 to 90, and 90 to 180 days after stroke onset were used to examine the evaluative properties of the measure.
Results: The PASS-TC scores exhibited differences between the patients with disability and the patients without disability at the 4 time points. The scale, however, showed a notable ceiling effect at the 4 time points (>30% of the subjects), indicating a limited discriminative ability between individuals. The scores of the PASS-TC at the 4 time points were moderately correlated with the CADL scores at 1 year after stroke onset (Spearman rhof.5), evidence of its predictive validity. The responsiveness of the PASS-TC was moderate at 14 to 30 days after stroke (standardized response mean [SRM]=.65) and limited at 30 to 90 and 90 to 180 days after stroke (SRM=.42 and .02, respectively).
Discussion and conclusion: The results provide evidence that the PASS-TC can predict CADL function at 1 year after a stroke, but the discriminative and evaluative abilities are limited over the first 6 months after a stroke. To promote the utility of the PASS-TC in stroke research, it will be necessary to reduce its ceiling effect and improve its evaluative ability.