Perceptions of Health and Relationships to Disability Measures among People with Multiple Sclerosis.

Researchers use various measures to assess health status, impairment, functional limitations, and disability among people with Multiple Sclerosis. However, conceptually and empirically relationships among measures are not always clear. The purpose of this study was to examine the relationships among measures of impairment, disability, functional status and health related outcomes within a sample of 443 individuals with MS. A secondary purpose was to compare the reported health status of this sample to the health status of a population-based sample of individuals with and without disabilities. While both the MS sample and a population-based sample of individuals with activities limitations indicated poorer health than did their non-disabled counterparts, the MS sample reported more days in the past month when physical and mental health was not good and more days when poor health kept them from usual activities than the population-based sample of individuals with disabilities. Most measures were moderately intercorrelated, but the pattern suggests that issues such as the time period specified may affect the relationships. Researchers are advised to carefully consider operational as well as conceptual definitions, length of proposed measures, and appropriate time frame, as well as more traditional criteria of reliability and validity when selecting study measures.