Responsiveness, minimal detectable change, and minimal clinically important difference of the sitting balance scale and function in sitting test in people with stroke

Background: Limited studies have examined the responsiveness of the Sitting Balance Scale (SBS) and Function in Sitting Test (FIST). No studies have investigated the psychometric properties of these tools in skilled nursing facilities. Objective: The purposes of the study were (1) to examine responsiveness of the SBS and FIST, in people with stroke, receiving rehabilitation in skilled nursing facilities; and (2) to estimate the MDC and MCID of these scales. Methods: Forty participants completed the FIST, SBS, and Barthel Index (BI) at admission and discharge. Internal responsiveness of the FIST and SBS was measured using Effect Size (ES) and Standardized Response Mean (SRM). Examining the association between the difference in scores on the SBS or FIST and the difference in scores on the BI determined external responsiveness. MDC and MCID were estimated for both measures. Results: The ES and the SRM for both scales were large (1.01–2.30) indicating excellent internal responsiveness. Both scales demonstrated satisfactory external responsiveness, showing good association with change in BI scores (p < .01). MDC₉₀ of the SBS and the FIST were 2.3 and 3.9, respectively. Anchor-based MCID estimates were 4.5 and 3.5, and distribution-based were 3.5 and 4.8 for the SBS and FIST, respectively. Conclusions: Both scales demonstrate sufficient responsiveness in the skilled nursing setting. Our findings suggest a change of 5 on the SBS and 4 on the FIST are clinically important, and clinicians may use these values to assess patient progress.