The Eating and Drinking Ability Classification System for cerebral palsy: a study of reliability and stability over time

AIM: This study evaluated the inter-observer reliability and stability over time of the Eating and Drinking Ability Classification System (EDACS) for children and young people with cerebral palsy (CP). METHOD: Case records for 97 children with CP were examined to collect retrospective data about eating and drinking abilities at four time-points with a minimum of 2 years between each time-point. Sex, Gross Motor Function Classification System (GMFCS) level, presence of feeding tube and orthopaedic issues were recorded from case records. One speech and language therapist (SaLT1) classified eating and drinking ability using EDACS for all cases at all time-points; SaLT2 assigned EDACS levels for 50 cases at time-point 1; SaLT3 assigned EDACS levels for 24 cases at all time-points. Inter-observer reliability and stability over time were assessed using the Intraclass Correlation Coefficient (ICC). Associations between EDACS levels and functioning recorded with other Functional Classification Systems (FCSs) were calculated using Kendall's tau (τ). RESULTS: Out of 97 children, 48 were male, 48 had feeding tubes, and 83 had orthopaedic issues. ICC for EDACS levels recorded by SaLT1 across all time-points was 0.97 (95% CI 0.96-0.98); changes in EDACS levels occurred infrequently and never by more than one level. ICC between SaLT1 and SaLT2 at time-point 1 was 0.8 (95% CI 0.67-0.89); ICC between SaLT1 and SaLT3 across all time-points was 0.95 (95% CI 0.92-0.98). Association between GMFCS and EDACS was moderate (τ= 0.58). INTERPRETATION: Retrospective use of EDACS to classify children's eating and drinking abilities appears reliable; EDACS appeared stable over 6 or more years in 86% of the cases.