Minimal Clinically Important Difference of GRASSP Version 1 in Acute Cervical Traumatic Spinal Cord Injury

The Graded Redefined Assessment of Strength, Sensibility, and Prehension Version 1 (GRASSP v1) is a validated measure of upper extremity impairment shown to be sensitive and responsive for traumatic cervical spinal cord injury (SCI) in both North American (NA) and European (EU) cohorts. The minimal clinically important difference (MCID) is the quantitative change in an assessment scale which patients perceive as being beneficial. Our aim was to establish the MCID of all subtests of the GRASSP v1 for cervical SCI. We prospectively analyzed 127 patients from NA and EU for up to 6 months following motor complete and incomplete cervical SCI using the GRASSP v1, SCIM, and ISNCSCI. We used a patient global rating of change and the anchor-based method to calculate MCID of GRASSP v1 at 6-months post injury. MCID was established for the whole group, dividing the sample by "better" and "much better". Improvement in GRASSP v1 Strength and Prehension Performance scores of 13 and 3 are the MCID for the "better" category, and 19 and 7 are the MCID for the "much better" category, respectively. MCID was also established for the motor complete and incomplete groups. Improvement in GRASSP v1 Strength and Prehension Performance scores of 12 and 6 are the MCID for the motor complete group, and 17 and 12 are the MCID for the motor incomplete group, respectively. The GRASSP v1 Strength subscore is the most sensitive for detecting meaningful clinical change in patients and is most closely related to measures of independence. Thus, use of GRASSP v1 Strength and Prehension Performance as measures of change is substantiated by this study.