People with multiple sclerosis (MS) experience symptoms in multiple domains. High-quality patient-reported outcomes (PROs) that assess multiple domains can aid healthcare providers in assessing these symptoms and may support remote disease monitoring. The “SymptoMScreen” PRO correlates with other PROs in MS; however, whether the SymptoMScreen or its component domains are associated with performance-based or clinician-assessed outcomes is unknown.
Dr. Gary Cutter, professor in the department of biostatistics at the University of Alabama at Birmingham School of Public Health collaborated with a team of researchers from across the country to validate SymptoMScreen and its domains against performance-based, clinician-assessed measures or other well-validated diagnostic tools.
The research team recruited participants with MS from a large tertiary care center. At routine clinic visits participants completed the MS performance test (MSPT), which is an iPad-based application that objectively assesses walking speed, manual dexterity, processing speed, and low contrast letter acuity. Expanded Disability Status Scale (EDSS) scores were assessed in a subset. Participants also completed an online SymptoMScreen following clinic visits. They assessed criterion and construct validity by calculating Spearman rank correlations between the 12 SymptoMScreen domains and respective clinical outcomes. They evaluated test-retest reliability using intra-class correlation coefficients [ICC], and internal consistency reliability using Cronbach’s alpha.
The 102 participants were predominantly female (78 percent), of average age [standard deviation]: 47.6 [12.3] years, with an average disease duration: 13.1 [10.0] years); 60 participants completed the SymptoMScreen and EDSS. Composite SymptoMScreen scores were associated with EDSS (r = 0.71; 95 percent CI 0.54, 0.83). For individual domains, strong correlations were observed between mobility scores and walking speed (r = 0.63; 95 percent CI: 0.48, 0.75) and hand function scores with manual dexterity (r = 0.52; 95% CI: 0.36, 0.65). More moderate correlations were detected for the cognition domain with processing speed (r=-0.37; 95 percent CI: -0.53, -0.18) and for the visual function domain with low contrast letter acuity at 2.5 percent contrast (r=-0.33; 95 percent CI -0.54, -0.08). Both test-retest and internal consistency reliability measures for overall SymptoMScreen scores were high (ICC: 0.88; 95 percent CI: 0.80, 0.93; Cronbach’s alpha: 0.93; 95 percent CI: 0.90, 96).
The authors concluded that the SymptoMScreen is practical outcome measure whose subscales may provide a valid assessment of corresponding performance-based and clinician-assessed measures among people with MS with mild-to-moderate disability.