Delayed cognitive processing and treatment status quo bias in early-stage multiple sclerosis

The evolving therapeutic landscape requires more participation of patients with relapsing remitting multiple sclerosis (RRMS) in treatment decisions. The aim of this study was to assess the association between patient's self-perception, cognitive impairment and behavioral factors in treatment choices in a cohort of patients at an early stage of RRMS.

We conducted a multicenter, non-interventional study including adult patients with a diagnosis of RRMS, a disease duration ≤18 months and receiving care at one of the 21 participating MS centers from across Spain. We used patient-reported measures to gather information on fatigue, mood, quality of life, and perception of severity of their MS. Functional metrics (Expanded Disability Status Scale [EDSS], cognitive function by the Symbol Digit Modalities Test [SDMT], 25-foot walk test) and clinical and radiological data were provided by the treating neurologist. The primary outcome of the study was status quo (SQ) bias, defined as participant's tendency to continue taking a previously selected but inferior treatment when intensification was warranted. SQ bias was assessed based on participants treatment preference in six simulated RRMS case scenarios with evidence of clinical relapses and radiological disease progression.

Of 189 participants who met the inclusion criteria, 188 (99.5%) fully completed the study. The mean age was 36.6 ± 9.5 years, 70.7% female, mean disease duration: 1.2 ± 0.8 years, median EDSS score: 1.0 [IQR=0.0-2.0]). Overall, 43.1% patients (n = 81/188) had an abnormal SDMT (≤49 correct answers). SQ bias was observed in at least one case scenario in 72.3% (137/188). Participant's perception of their MS severity was associated with higher SQ bias (β coeff 0.042; 95% CI 0.0074-0.076) among those with delayed cognitive processing. Higher baseline EDSS and number of T2 lesions were predictors of delayed processing speed (OR EDSS=1.57, 95% CI: 1.11-2.21, p = 0.011; OR T2 lesions=1.50, 95% CI: 1.11-2.03, p<0.01). Bayesian multilevel model accounting for clustering showed that delayed cognitive processing (exp coeff 1.06; 95% CI 1.04-1.09) and MS symptoms severity (exp coeff 1.28; 95% CI 1.22-1.33) were associated with SQ bias.

Over 40% of patients in earlier stages of RRMS experience delays in cognitive processing that might affect their decision-making ability. Our findings suggest that patients' self-perception of disease severity combined with a delay in cognitive processing would affect treatment choices leading to status quo bias early in the course of their disease.