UK Renal Registry 15th annual report: Appendix E methodology for estimating catchment populations of renal centres in England for dialysis patients.

Providing accurate centre-level incidence and prevalence rates for patients receiving renal replacement therapy (RRT) in the UK was limited until the 13th Annual Report by the difficulty in estimating the catchment population from which the RRT population was derived. One reason for this was that the geographical boundaries separating renal centres are relatively arbitrary and dependent upon a number of factors including referral practice, patient choice and patient movement. Previously, incidence and prevalence rates had been calculated at Local Authority/Primary Care Trust/Health Board level where denominator data were available, but not at renal centre level. UK Renal Registry (UKRR) Annual Reports prior to the 13th suggested an estimate of the size of the catchment populations. These were extrapolated figures originally derived from data in the 1992 National Renal Survey undertaken by Paul Roderick. The purpose of this document is to present an estimate of the dialysis catchment population for all renal centres in England. The document also contains a methodological description and discussion of the limitations of this estimate. These catchment population estimates were used in the 13th Annual Report (chapter 1: UK RRT Incidence in 2009: national and centre-specific analyses) to calculate RRT incidence rates by renal centre, rather than only by Primary Care Trust/HB. From the 14th Annual Report both incidence and prevalence rates are given by renal centre as well as by Primary Care Trust/HB. Methods