Centre variation in incidence, indication and diagnosis of adult native renal biopsy in Scotland.

Background. UK native renal biopsy incidence is unknown. Biopsy registries in other countries indicate that the incidence of renal biopsy varies widely. Indications for renal biopsy are largely opinion based. Methods. The Scottish Renal Biopsy Registry aimed to analyse the incidence of native renal biopsy in Scotland and examine indications and diagnoses obtained where practice varied widely. Results. Consecutive native adult renal biopsies performed in eight of the nine Scottish regions that include 82.4% of the population between 2002 and 2006 were examined. A total of 2480 native renal biopsies were performed equating 126.3 biopsies per million population per year (PMP/year). A total of 56.9% of patients were male, mean age 55.6 years (SD 1.3). The centres varied widely, from a lowest mean annual incidence of 65.8 PMP/year in Fife to the highest of 170.7 PMP/year in Tayside. The prospectively recorded indications and diagnoses were compared between Greater Glasgow, Clyde and Forth Valley (GC&FV) (population 1.56 million, 101.6 biopsies PMP/year) and Tayside (population 0.39 million, 177.4 biopsies PMP/year). Differing incidence of renal biopsy in these regions was mainly explained by patients with proteinuria and preserved renal function in the absence of nephrotic syndrome (19.2 PMP/year in GC&FV versus 60.8 PMP/year in Tayside), probably due to variation in nephrologists' opinion about the utility of biopsy for this indication. Tayside diagnosed more primary glomerulopathies, diabetic nephropathy and chronic ischaemia than GC&FV. Conclusions. We have demonstrated wide regional variability in incidence of native renal biopsy within a single country, with analysis suggesting that this is mainly explained by uncertainty about the utility of renal biopsy for patients with proteinuria and preserved renal function. Further studies are required to determine the value of renal biopsy in this setting.