Prevalence and Magnitude of Perceived Dual-Task Difficulties in People With Multiple Sclerosis: An International Study

Abstract

Objective: To investigate the prevalence and magnitude of dual-task (DT) difficulties and the discriminative ability of 3 questionnaires evaluating perceived DT difficulties: the Dual-Tasking Questionnaire (DTQ), Dual-Task Screening List (DTSL), and Dual-task Impact on Daily life Activities Questionnaire (DIDA-Q). Design: Multicenter, cross-sectional study. Setting: Persons with multiple sclerosis (pwMS) and those without multiple sclerosis were recruited from 7 centers across 6 countries. Participants: A total of 540 participants (N=540): 175 with mild disability (mean Expanded Disability Status Scale, 2.1; mean age, 42.9), 181 with moderate-to-severe disability (mean Expanded Disability Status Scale, 5.3; mean age, 51.9), and 184 of those without multiple sclerosis (mean age, 44.8). Interventions: Not applicable. Main Outcome Measures: The cutoff scores of the DTQ, DTSL, and DIDA-Q and prevalence of DT difficulties were calculated. The effect size (ES) was calculated to determine the magnitude of the differences between groups (pwMS vs those without multiple sclerosis). The discriminative properties were identified by the area under the receiver operating characteristic curve (AUC). Cutoff values were estimated as the mean survey score plus 2 SDs of those without multiple sclerosis. Results: Prevalence ranged from 49%-87% in the moderate-to-severe disability and 25%-45% in the mild disability group. The cutoff scores were 45 of 100 for DTQ, 25 of 100 for DTSL, and 14 of 76 for DIDA-Q. The DTQ (ES, 0.61), DTSL (ES, 0.73), and DIDA-Q (ES, 0.80) demonstrated discriminative ability with a moderate-to-large ES, showing greater perceived DT difficulties in pwMS compared with those without multiple sclerosis. The DIDA-Q had the largest AUC (0.904) compared with DTSL (0.866), and DTQ (0.802). Conclusions: The DT difficulties were already perceived in almost half of the mildly disabled patients and increased with disability severity. The DTQ, DTSL, and DIDA-Q show discriminative ability, with the highest AUC and ES observed in DIDA-Q. The DTQ, DTSL, and DIDA-Q can clearly be used in pwMS for clinical and research purposes. Archives of Physical Medicine and Rehabilitation 2026;107:875-83 (c) 2025 by the American Congress of Rehabilitation Medicine