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

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 rehabilitationThe 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.