Creating small-area deprivation indices: a guide for stages and options

Small-area composite measures (such as for deprivation, geographic access or green space) have become increasing popular among both researchers and policy makers and are frequently used to compare or rank areas. Because of their seeming simplicity and wide appeal, it is important to set out for researchers and users the different stages and options that underlie the development of composite indices. Using small area deprivation measures as an example, this article reviews the key decisions faced by researchers from choosing the data and variables to validation and measuring uncertainty. Our aim is to guide researchers in the planning and following through with the process of developing a small-area measure. To date, the different choices are often not considered and the methodological decisions tend to be based on tradition or convenience. While there is no widely accepted framework for choosing between methods, we argue that researchers should compare different methods and justify their decisions at each stage of the process. In particular, more emphasis should be put on validating measures for different population subgroups. © 2020 Author(s) (or their employer(s)). No commercial re-use. See rights and permissions. Published by BMJ.