Translation, cultural adaptation, and validation of a screening test for cognitive and behavioural changes in amyotrophic lateral sclerosis

Abstract

Purpose: To describe challenges of translating and culturally adapting the Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis (ALS) Screen into Norwegian (ECAS-N), evaluate its content validity; provide age- and education-balanced norms for verbal fluency and cut-off values for abnormal performance. Materials and methods: Translation to Norwegian and back-translation to English complied with standard methods. Patients and ALS experts evaluated the relevance, comprehensiveness and comprehensibility of the translated ECAS (ECAS-N). Content validity indexes at the item level (I-CVI), scale level (S-CVI) and inter-rater agreement were calculated. Performance of controls determined norms for written and spoken verbal fluency (n = 559) and cut-off scores for abnormal performance (n = 85). Results: High levels of content validity was achieved for all items of the ECAS-N, I-CVI, S-CVI and inter-rater agreement was 87.5%. Age- and education-balanced norms for written and spoken verbal fluency were produced. Cut-off scores of abnormal performance were slightly lower than the original ECAS. Conclusions: The ECAS-N holds promise for detecting cognitive and behavioural impairment in Norwegian patients with ALS. Cut-off scores are situational and could slightly vary between different cultures. The ECAS-N can be used in international research, but researchers should be aware of the differences between the tests applied in the studies.Implications for rehabilitation The ECAS-N, a Norwegian version of the English-language ECAS was produced for clinical use in Norway. Rigorous translation methods were used, and expert-judged modifications were made for Norwegian-specific culture and language nuances. Determination of ECAS-N cut-off scores for abnormal cognition was guided by a biostatistician, are slightly lower than the original ECAS, and are based on results from an objectively calculated number of healthy Norwegians. A nuanced picture of cognitive impairment in ALS drawn from a well-developed scale as the ECAS-N can contribute to a management process better tailored to patients’- and carers’ individual needs.