Constructing the Index
The Veterinary Care Accessibility Score is an index generated by bringing together multiple data sources, ranking them, summing them and ranking those results. This is a common method for creating indices. There will be more detail on the process in our upcoming paper on the VCAS, but check out the summary below.
Establish Geographic Scale: County
We chose the county level for a few reasons. First, data are readily obtainable because it is a common level at which to aggregate. Second, it achieves a “just right” level of granularity – not too broad, and not too specific. Finally, it’s familiar; people are used to hearing about data at the county level.
The table below summarizes the key variables included in the index as well as their sources and justification.
For each variable, a percentile rank was calculated. Next The percentile ranks were summed at the county level. Then, these county-level percentile ranks were summed. Finally these summed percentiles were given a percentile rank across all counties. The result: The VCAS provides a relative measure of the accessibility of veterinary care for counties throughout the country. It is not an absolute scale as data do not yet exist to provide reliable benchmarks for such absolute measures.