The Multiple Sclerosis Impact Scale (MSIS-29)A new patient-based outcome measure

摘要: Changes in health policy have underlined the importance of evidence-based clinical practice and rigorous evaluation patient-based outcomes. As outcome measurement is particularly important treatment trials multiple sclerosis, a number disease-specific instruments been developed recently. One limitation these that none was using standard psychometric approach reducing large item pool generated from people with sclerosis. Consequently, an measure for sclerosis disease specific combines patient perspective methods will complement existing instruments. The aim this study to develop such measure. Standard were used. A 129 questionnaire items interviews 30 expert opinion literature review. administered by postal survey 1530 selected randomly Multiple Sclerosis Society membership database. Redundant those limited properties removed. remaining (n = 41) grouped into scales factor analysis, then refined form Impact Scale (MSIS-29), instrument measuring physical (20 items) psychological (nine impact Five MSIS-29 (data quality, scaling assumptions, acceptability, reliability validity) examined separate 1250 members. preliminary responsiveness undertaken 55 admitted rehabilitation intravenous steroid relapses. satisfied all criteria. Data quality excellent, missing data low (maximum 3.9%), test-re-test high (r 0.65-0.90) scale scores could be >98% respondents. Item descriptive statistics, convergent discriminant validity, analysis indicated it legitimate generate summing items. showed good variability, small floor ceiling effects, internal consistency (Cronbach's alpha