The Kidney Care Atlas is a landmark in the study of variation in kidney care in England. Data from the UKRR and QOF, as well as other datasets, have been used to illustrate how aspects of healthcare specific to kidney disease vary. There are now 2 versions of the pdf available to download - a high resolution file (8 Mb) and a low resolution file (4.5 Mb).
See: Right Care Kidney Care Atlas page. You can also view an interactive version of the Atlas here.