Adaptation and Validation of Version B of the Edinburgh Cognitive and Behavioural ALS Screen for the Portuguese Population

Objective: This study aims to adapt and provide psychometric support for the validation of version B of the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) for the Portuguese population, addressing the need for consistent cognitive evaluations in amyotrophic lateral sclerosis (ALS). A second culturally adapted ECAS screen facilitates the accurate characterization of ALS progression, mitigates learning effects, and supports tailored care management.

Methods: The adaptation process included forward-backward translation, cultural adaptation, and cognitive debriefing on a prospective sample of 193 ALS patients and 106 controls. A multiple regression analysis identified predictors relevant for establishing ECAS cut-off scores. Psychometric evaluations, including reliability assessments and tests of convergent, construct, and criterion validity, were conducted. Additionally, version A's psychometric properties were reevaluated with complementary analyses and a larger sample.

Results: Version B demonstrated good internal consistency with Cronbach's alpha of 0.802, comparable to the previously established version A. Moderate inter-item correlations further supported reliability, reflecting internal coherence. Equivalence testing between the Portuguese versions supported convergent validity, confirming version B's alignment with version A's theoretical framework. Exploratory factor analysis provided preliminary support for construct validity, and receiver operating characteristic analyses established cut-off values for both versions, revealing moderate sensitivity with a tendency toward false negatives, and higher specificity.

Conclusions: This study provided evidence for the cultural suitability, reliability, and validity of the Portuguese ECAS B. As evidence supports the equivalence of the Portuguese ECAS versions, they can be used for flexible screenings and applied with the calculated cut-off values to enhance diagnostic accuracy.