REFUSING PASAT: A WINDOW INTO CLINICAL VULNERABILITY OF PEOPLE WITH MULTIPLE SCLEROSIS

The Paced Auditory Serial Addition Test (PASAT) is a validated measure of sustained attention, working memory, and information processing speed in people with Multiple Sclerosis (PwMS). Its limited acceptability and high refusal rates may constrain clinical interpretability, while potentially conveying meaningful information beyond standard performance metrics. This retrospective study examined whether PASAT non-completion at initial assessment identifies a subgroup of PwMS at higher clinical vulnerability.
Data from 1154 PwMS were analyzed. Participants were divided into three groups according to baseline PASAT performance: missing (refusal), low, and high. One-way ANOVAs or non-parametric tests were employed to compare groups on demographic, disease-related, cognitive, and functional measures, including both patient-reported and clinician-assessed outcomes.
Participants who did not complete the PASAT (N= 224) were older (60.1 ± 13.5 years), had longer disease duration (18.9 ± 12.2 years), higher disability (EDSS= 6.1 ± 2.0), and lower educational level (9.9 ± 3.9 years) than low- and high-PASAT groups (all p< 0.05). They also exhibited poorer cognitive performances as measured by MoCA (17.4 ± 6.5) and SDMT (22.5 ± 13.6) and reduced functional status reflected by greater assistance needs across domains (FIM= 91.1 ± 29.3).
PASAT non-completion at first assessment identifies a subgroup of PwMS with greater disability, cognitive deficits, and functional limitations. Test refusal may serve as a clinically relevant indicator of overall vulnerability, to be interpreted alongside established measures of disease burden. Assessing PASAT refusal may help clinicians to identify at-risk subgroups who may benefit from tailored interventions, complementing information obtained from conventional performance-based metrics.