BackgroundRecently published guidelines on the medical management of renal stone disease did not address relevant topics in the field of idiopathic calcium nephrolithiasis, which are important also for clinical research.DesignA steering committee identified 27 questions, which were proposed to a faculty of 44 experts in nephrolithiasis and allied fields. A systematic review of the literature was conducted and 5216 potentially relevant articles were selected; from these, 407 articles were deemed to provide useful scientific information. The Faculty, divided into working groups, analysed the relevant literature. Preliminary statements developed by each group were exhaustively discussed in plenary sessions and approved.ResultsStatements were developed to inform clinicians on the identification of secondary forms of calcium nephrolithiasis and systemic complications; on the definition of idiopathic calcium nephrolithiasis; on the use of urinary tests of crystallization and of surgical observations during stone treatment in the management of these patients; on the identification of patients warranting preventive measures; on the role of fluid and nutritional measures and of drugs to prevent recurrent episodes of stones; and finally, on the cooperation between the urologist and nephrologist in the renal stone patients.ConclusionsThis document has addressed idiopathic calcium nephrolithiasis from the perspective of a disease that can associate with systemic disorders, emphasizing the interplay needed between urologists and nephrologists. It is complementary to the American Urological Association and European Association of Urology guidelines. Future areas for research are identified.

The Consensus Group deliberated on a number of questions concerning urine and stone analysis over a period of months, and then met to develop consensus. The Group concluded that analyses of urine and stones should be routine in the diagnosis and treatment of urinary stone diseases. At present, the 24-h urine is the most useful type of urine collection, and accepted methods for analysis are described. Patient education is also important for obtaining a proper urine sample. Graphical methods for reporting urine analysis results can be helpful both for the physician and for educating the patient as to proper dietary changes that could be beneficial. Proper analysis of stones is also essential for diagnosis and management of patients. The Consensus Group also agreed that research has shown that evaluation of urinary crystals could be very valuable, but the Group also recognizes that existing methods for assessment of crystalluria do not allow this to be part of stone treatment in many places.

Although the effect size is modest, urolithiasis may cause chronic kidney disease and, thus, it is mandatory to assess patients with renal stones for the risk of chronic kidney disease/end stage renal disease. We suggest that all guidelines dealing with renal stone disease should include assessment of this risk.

Kidney stones represent a common condition characterized by significant morbidity and economic costs. The epidemiology of kidney stones is not completely understood and may vary substantially based on geographic, socioeconomic and clinical factors; the present study aims at defining the prevalence and diagnostic patterns of kidney stones in a cohort representative of the general population in Florence, Italy. A sample of 1,543 adult subjects, all Caucasians, was randomly selected from a population of over 25,000 subjects followed by 22 general practitioners (GPs). Subjects were administered a questionnaire requesting the patient's age and sex, any history of kidney stones and/or colics and the prescription of kidney ultrasound (US) examination. GPs data-bases were also interrogated. Crude and adjusted prevalence proportions and ratios (PRs) with corresponding 95% confidence intervals (CIs) were computed. Furthermore, the association between the practice pattern of each physician with respect to US prescription and the prevalence of kidney stones was investigated. The overall prevalence of kidney stones was 7.5% (95% confidence interval 6.2, 8.9%), increasing with age until 55-60 years and then decreasing. About 50% reported recurrent disease. There were no significant differences in prevalence among males and females. GPs who tended to prescribe more US examinations were more likely to have more patients with kidney stones (adjusted PR 1.80, 95% CI 1.11, 2.94; p = 0.020). The present study confirms both the high prevalence and the regional variability of kidney stones. Practice patterns may be involved in such variability.