Translation, reliability, and validity of the Norwegian version of the ABILHAND-NMD and the ACTIVLIM for Myotonic Dystrophy type 1

Abstract

Purpose To translate ABILHAND-NMD and ACTIVLIM into Norwegian and assess their psychometric properties in adults with Myotonic Dystrophy type 1(DM1). Methods ABILHAND-NMD and ACTIVLIM were translated into Norwegian through a standardized translation process. Psychometric properties of the translated questionnaires were tested. Intraclass correlation coefficient (ICC3.1) was used to assess test-retest reliability and Cronbach’s α for internal consistency. The validity of the questionnaires was also assessed. Results A total of 39 adults with DM1 were included. We found excellent test-retest reliability on ABILHAND-NMD (ICC 0.91) and ACTIVLIM (ICC 0.93). We found a good internal consistency of ABILHAND-NMD with Cronbach’s α (95%CI) of 0.80 (0.69–0.88) and ACTIVLIM with Cronbach’s α (95%CI) of 0.88 (0.82–0.93) An expert group of healthcare professionals and a pilot group reported good face and content validity. We found a high correlation between ABILHAND-NMD and ACTIVLIM (r = 0.75), p < 0.001 implying good convergent validity. ABILHAND-NMD and ACTIVLIM showed no floor effect, but a potential for ceiling effect. Conclusion The Norwegian versions of ABILHAND-NMD and ACTIVLIM are reliable and valid patient reported outcome measures for Myotonic Dystrophy type 1. The questionnaires are easy to administer as they take a short time to answer, and the participants reported no problems understanding the questions. Implications for rehabilitation Myotonic Dystrophy type 1 cause myopathy and altered muscle function. Impaired arm- and hand function increases patients’ need for assistance and reduces independence. The use of patient reported outcome measures (PROMs) to uncover impairments and activity limitations is important in clinical practice and research. The Norwegian versions of ABILHAND-NMD and ACTIVLIM are reliable and valid measures of manual ability and activity limitations for adults with Myotonic Dystrophy type 1.