Benefit evaluation in multiple sclerosis relapse treatment from the patient's perspective - Development and validation of a new questionnaire

Background: Little is known on how to measure patient-relevant benefit of relapse treatment in relapsing-remitting multiple sclerosis (MS). The objective of this study was to develop and validate a new method for monitoring recovery from MS relapses and patient-relevant treatment benefits. Methods: A 27-item questionnaire was developed using a multi-step approach comprising open item collection, multidisciplinary expert panel and cognitive debriefing. It was evaluated regarding psychometric properties and feasibility in a longitudinal validation study with 100 patients with MS undergoing relapse treatment. Construct validity was tested by correlations with patient and physician global impressions of change as well as disease-specific and generic health-related quality of life (HRQoL) measures. Results: Results of the feasibility survey indicated high patient acceptance. Reliability was high (Cronbach's alpha = 0.90). While the Expanded Disability Status Scale (EDSS) was not sensitive to change, Patient Benefit Index for Multiple Sclerosis (PBI-MS) showed a high correlation cross-sectionally with patient global impression of change (PaGIC) (r = 0.60, p < 0.001). Significant moderate to high correlations were found with change in generic HRQoL (r = 0.55-0.61, p < 0.001) and lower correlations with change in disease-specific HRQoL (r = -0.36, p < 0.01). Conclusion: The PBI-MS is a reliable and valid instrument for ascertaining patient-relevant benefits of acute relapse treatment; it appears suited for use in routine care and in clinical or health care studies.