Abstract
BACKGROUND: Survey-based studies are frequently used to describe the economic impact of multiple sclerosis (MS). However, there is no validated health resource survey available, preventing comparison of study results and meaningful conclusions regarding the efficiency of long-term treatments. OBJECTIVE: The aim of this study was to develop and validate a tablet- and paper-based MS health resource utilization survey. METHODS: We developed and validated the Multiple Sclerosis Health Resource Utilization Survey (MS-HRS), consisting of 24 cost items for paper and tablet users. Data for validation came from two large German observational studies. Survey practicability was assessed according to the response rate. Reliability was described using test-retest reliability as well as Guttman lambda. Construct validity was assessed as convergent and discriminant validity via correlations with associated patient-reported outcomes and known-group analyses. RESULTS: In total, 2207 out of 2388 (response rate: 92.4%) patients completed the survey and were included to determine psychometric properties. The test-retest reliability had an intraclass correlation coefficient of 0.828 over a course of 3 months. Convergent validity analyses showed that total costs correlated positively with increased disability (r=0.411, P<.001). For discriminant validity, correlations of total costs with the Treatment Satisfaction Questionnaire for Medication ranged from -0.006 (convenience) to -0.216 (effectiveness). The mean annual cost was €28,203 (SD €14,808) (US $39,203; SD US $20,583) with disease-modifying therapies. CONCLUSIONS: The MS-HRS is a multilingual, reliable, valid, electronically available, and easy-to-administer questionnaire providing a holistic cross-sectional and longitudinal assessment of resource utilization in patients with MS.