The minimal important difference for the Postural Assessment Scale for Stroke Patients in the subacute stage

Background: The minimal important difference (MID) of the Postural Assessment Scale for Stroke Patients (PASS) remains unknown, limiting the interpretation of change scores. Objectives: To estimate the MID of the PASS in patients with subacute stroke. Methods: Data at admission and discharge for 240 participants were retrieved from a longitudinal study. The “mobility” item of the Barthel Index was used as the anchor for indicating the improvement of posture control. Receiver operating characteristic (ROC) method was used to estimate the anchor-based MID of the PASS. Results: The ROC method identified a MID of 3.0 points, with a sensitivity of 81.0 % and a specificity of 75.6 %. Conclusion: The MID of the PASS was 3.0 points, indicating that if a patient achieves an improvement of 3.0 or more points on the PASS, they have a clinically important improvement in posture control. Our results can help in interpreting change scores and aid in understanding the clinical values of treatment outcomes.