Evaluating Relapse Knowledge in People with Multiple Sclerosis: A Cross-Sectional Study on the Development and Validation of the Relapse Knowledge Questionnaire

BACKGROUND: Multiple sclerosis (MS) knowledge is a prerequisite for active patient engagement in medical decision-making. Treatment of relapses in MS is a clinical field with many uncertainties and each acute relapse requires decisions regarding possible options for action, indicating the need for patient involvement. However, there is no validated instrument assessing relapse knowledge in people with MS. Our study aims to develop a valid MS relapse questionnaire for use as an outcome instrument for educational interventions.

METHODS: A multidisciplinary panel developed the relapse knowledge questionnaire (RKQ) based on a previously developed questionnaire. We tested the RKQ on MS patients for comprehensibility, usability and acceptance in qualitative think-aloud interviews and conducted a cross-sectional quantitative online survey to validate the questionnaire. People with suspected or confirmed relapsing-remitting MS and a recent relapse experience were eligible for inclusion. We checked normal distribution of the RKQ score and determined the item difficulty. Construct validity was analysed using correlational analysis.

RESULTS: The final RKQ consists of 10 items. After minor changes of the RKQ during pre-testing (n = 2), pilot testing (n = 10) confirmed the usability and acceptance of the instrument. The subsequent validation study (n = 203) resulted in a mean item difficulty of 0.44, ranging from 0.18 to 0.83. Seven items were particularly difficult and answered incorrectly by more than 50 % of participants. Construct validity of the RKQ was satisfactory. The RKQ score correlated only weakly with participants' degree of education (|rp|>0.1), years since diagnosis (|rp|>0.1), and the intention to receive corticosteroids (|rp|>0.1).

CONCLUSION: This study indicates the validity of the RKQ and proposes that the RKQ is a suitable instrument to assess relapse knowledge in people with MS participating in educational interventions.