Cultural adaptation and validation of a peninsular Spanish version of the MSTCQ^© (Multiple Sclerosis Treatment...

Although subcutaneous treatments for multiple sclerosis (MS) have been shown to be effective, adverse reactions and pain may adversely affect treatment satisfaction and adherence. This study presents an adapted and validated Spanish version of the Multiple Sclerosis Treatment Concerns Questionnaire^© (MSTCQ), which evaluates satisfaction with the injection device (ID) across 4 domains: injection system (A), side effects (B) (flu-like symptoms, reactions, and satisfaction), experience with treatment (C) and benefits (D).

Two study phases: 1) Cultural adaptation process with input from experts (n=6) and patients (n=30). 2) Validation obtained by means of an observational, cross-sectional, multi-centre study evaluating 143 adult MS patients using an ID. Tools employed: MSTCQ^©, Patient-Reported Indices for Multiple Sclerosis (PRIMUS^©), and Treatment Satisfaction Questionnaire for Medication (TSQM^©). Psychometric properties: Feasibility (percentage of valid cases and floor/ceiling effects); Reliability (Cronbach α) and test-retest correlation (n=41, intraclass correlation coefficient, ICC); and construct validity (factor analysis of domains A and B) and convergent validity (Spearman rank-order correlation for MSTCQ^© vs TSQM^©).

Mean age (SD) was 41.94 (10.47) years, 63% of the group were women, and 88.11% presented relapsing-remitting MS. Mean (SD) EDSS score was 2.68 (1.82) points. MSTCQ^© completion was high (0%-2.80% missing data). Internal consistency was high at α=0.89 for the total score (A+B) and α=0.76, 0.89, and 0.92 for domains A, B, and C, respectively. The version demonstrated excellent test-retest reliability for the total (ICC=0.98) and for domains A, B, and C: ICC=0.82, 0.97, and 0.89, respectively. Factor analysis corroborated the internal structure of the original questionnaire. The association between total and domain scores on both the MSTCQ^© and the TSQM^© was moderately strong (Rho=0.42-0.74) and significant (P<.05 and P<.01).

The Spanish version of MSTCQ^© demonstrates appropriate psychometric properties.