Classification of Stone-Patients and Healthy Persons on the Basis of the Urinary Analysis

There are many reports on the differences between the urine of stone-formers and that of healthy controls. Some authors have emphasized, however, that the main difference is not between healthy persons and stone-patients in general but between the single and multiple (recurrent) stone-formers. It should not be overlooked that the reported differences represent the differences between the mean values of the groups whereas the mean values of individuals within each group and the values of the individual urinary sample may be scattered widely around the mean value of the group, producing a broad overlap between patients and controls. This may be demonstrated in the case of the urinary magnesium measured every day for eighteen days in a group of 16 recurrent stone-formers and 11 healthy controls.