  Composite indicators are a useful tool to summarize, measure and compare
changes among different communities. The UK Office for National Statistics has
created an annual England Health Index (starting from 2015) comprised of three
main health domains - lives, places and people - to monitor health measures,
over time and across different geographical areas (149 Upper Tier Level
Authorities, 9 regions and an overall national index) and to evaluate the
health of the nation. The composite indicator is defined as a weighted average
(linear combination) of indicators within subdomains, subdomains within
domains, and domains within the overall index. The Health Index was designed to
be comparable over time, geographically harmonized and to serve as a tool for
policy implementation and assessment. We evaluated the steps taken in the
construction, reviewing the conceptual coherence and statistical requirements
on Health Index data for 2015-2018. To assess these, we have focused on three
main steps: correlation analysis at different index levels; comparison of the
implemented weights derived from factor analysis with two alternative weights
from principal components analysis and optimized system weights; a sensitivity
and uncertainty analysis to assess to what extent rankings depend on the
selected set of methodological choices. Based on the results, we have
highlighted features that have improved statistical requirements of the
forthcoming UK Health Index.
