An Investigation of a C-MIST Index to Measure Functional Needs for Disaster Risk and Its Spatial Distribution in Florida Counties

In the absence of a single composite measure to assess, rank, and test disability and functional needs in the context of disaster, this study undertook an interdisciplinary approach to develop a composite index based on C-MIST theory. An examination into how well the CMIST index represents the multidimensional nature of disability and functional needs was conducted, as well as illustrating any gaps in the underlying dimensionalities of current social vulnerability indices. First, an index was constructed in accordance with the C-MIST theory for sixty-seven counties in the State of Florida, using an additive aggregation model. Second, the underlying data structure and measure validity were examined at the sub-component level of the C-MIST index, using Cronbach’s coefficient alpha (C-alpha) and using exploratory factor analysis to determine the dimensionality of the sub-components. Third, the results were spatially compared with a calculated functional needs prevalence rate. Results were also compared at the index sub-component level and against another index, SoVI, in order to explore possible relationships and trends. Results indicated the C-MIST Index appeared initially to be unidimensional and a consistent and valid instrument for assessing functional needs in Florida with a high C-alpha of 0.997. However, when reviewing factor analysis and results from the functional needs prevalence rate comparison, dimensionality of underlying data structure requires further research and testing at both sub-component and individual indicator levels.