Psychometric Properties of LUN-MS: A New Questionnaire to Identify the Unmet Needs of People With Multiple Sclerosis

BACKGROUND: We developed a 29-item Questionnaire, Long-term Unmet Needs in MS (LUN-MS) to identify the unmet needs of people with multiple sclerosis (pwMS). OBJECTIVE: To assess acceptability, test-retest reliability, internal consistency, and validity of the LUN-MS. METHODS: Participants completed the LUN-MS and MSIS-29 twice, four weeks apart. Acceptability was assessed by looking at the response rate in each time point. Reliability was calculated by comparing the response during the two time points using Cohen’s weighted kappa. Using principal component analysis, the dimensionality of the questionnaire’s items was reduced, to five domains and the internal consistency of each domain was assessed using Cronbach’s alpha. Concurrent validity was tested by comparing the total LUN-MS score against MSIS-29 and EQ-5D-3L using Pearson’s product-moment correlation coefficient. RESULTS: Among 88 participants, rate of completion at time points-1 and 2 was 96 and 80% respectively. Test-retest reliability for individual items was between fair to near-perfect (weighted Cohen’s kappa 0.39-0.81). The unmet needs could be divided into five internally consistent domains (Cronbach’s alpha 0.83-0.74): neuropsychological, ambulation, physical, interpersonal relationship and informational. Concurrent validity with MSIS-29 (r = 0.705, P < .001) and EQ-5D-3L (r = 0.617, P < .001) were good. CONCLUSION: LUN-MS is a reliable, valid, and acceptable tool to identify the unmet needs of pwMS.