The Edinburgh visual gait score - The minimal clinically important difference.

OBJECTIVE: The primary aim was to define the minimal clinically important difference (MCID) of the Edinburgh Visual Gait Score (EVGS) using correlations with the Gross Motor Function Classification System (GMFCS) and the Functional Assessment Questionnaire (FAQ). The secondary aim was to confirm the numerical value of the MCID in the Gait Profile Score (GPS). METHOD: The EVGS and GPS scores for 151 patients with diplegic cerebral palsy (GMFCS Levels I-III) were retrospectively identified from a database held at the study centre. One-hundred and forty-one patients had FAQ data available. RESULTS: The EVGS and GPS correlated with increasing GMFCS level (p<0.001) and FAQ score (p<0.001). A gradient of 3.8 (2.9-4.7) for the EVGS and 2.9 (2.1-3.7) for the GPS corresponded to a one-level change in GMFCS level. A gradient of 1.9 (1.3-2.4) for EVGS and 1.5 (1.1-2.0) for GPS corresponded to a one-point change in FAQ. CONCLUSIONS: The authors propose an MCID value of 2.4 for the EVGS; representing the improvement in gait score after surgery that is likely to reflect a clinical improvement in function. This MCID is closely related to other studies defining post-operative improvements in kinematic data (GPS) and may offer guidance to post-surgical changes that might reasonably be expected to either improve or prevent deteriorating function.