Some aspects of the adult urinary stone problem in Great Britain and Northern Ireland.

Abstract

SummaryIn a collection of 856 urinary calculi from Great Britain and Northern Ireland, the most abundant and frequently occurring crystalline constituents are the mono‐ and di‐hydrates of calcium oxalate and hydroxy‐ and carbonate‐apatite.On the basis of composition, most stones can be assigned to a few well‐defined groups. The most common composition type, accounting for 34% of the collection, is that composed of calcium oxalate+calcium phosphate. The oxalate can be either or both of the hydrates, often both are present, but the calcium phosphate is generally hydroxyapatite. Stones consisting of pure calcium oxalate make up 27% of the total, while those comprised of struvite+calcium phosphate contribute 17%. In the latter variety the calcium phosphate is almost invariably carbonate‐apatite. The other group considered consists of the pure calcium phosphate calculi which account for 7% of the collection.The incidence of stones in relation to their site in the urinary tract and the patient's age and sex has been investigated, together with the effect of the stone site, patient's age and sex on the distribution of calculi in the main composition groups and the effect of composition, site, age and sex on the stone weight. Most of these variables have a significant effect on one another.The incidence of stones is also related to daily occupation, professional workers being 10 times more likely to develop urolithiasis than labourers.We thank the Medical Research Council and Nuffield Foundation who financed most of this work and Mr D. Sturt who kindly agreed to the participation of the Computer Centre in this project. We are greatly indebted to Mr N. W. Please for advice and many helpful discussions on the statistics and for carrying out the analysis of variance. Finally, we are grateful to the many surgeons and physicians who provided the stones and the data.