Validity of the Dutch version of the Amyotrophic Lateral Sclerosis Assessment Questionnaire, ALSAQ-40, ALSAQ-5.

The objective was to validate the Dutch translation of the 40-item and 5-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-40, ALSAQ-5). Eighty-one ALS patients participated in this cross-sectional study. The measures used were the ALSAQ-40, the ALSAQ-5, MOS Short-Form-36 (SF-36) and Revised ALS Functional Rating Scale (ALSFRS-R). The Dutch ALSAQ-40 was sensitive to differences in disease severity (all scales Kruskal-Wallis, p<0.05), had no floor and few ceiling effects (Communication, Eating and Drinking scales), had excellent internal consistency reliability (all scales Cronbach's alpha >0.90, all item to subscale correlations above 0.40) and showed good construct validity as it correlated as expected with SF-36 and ALSFRS-R scores. The total and item scores of the ALSAQ-5 were strongly correlated with the corresponding total and subscale scores of the ALSAQ-40 (Spearman's rho >0.80). The ALSAQ-5 and ALSAQ-40 showed comparable correlations with the subscales of the SF-36 and the ALSFRS-R, except for Activities Daily Living and Independence (ADL). All other results of the Dutch ALSAQ-40 and ALSAQ-5 were comparable to those of the original UK questionnaires. It is concluded that the psychometric properties of the Dutch version of the ALSAQ-40 and the ALSAQ-5 are good and similar to those of the original English version.