The Swiss Kidney Stone Cohort (SKSC), a longitudinal, multi-centric, observational cohort to study course and causes of kidney stone disease in Switzerland

Introduction: Kidney stone disease has a high prevalence worldwide of approximately 10 % of the population and is characterized by a high recurrence rate Kidney stone disease results from a combination of genetic, environmental, and life-style risk factors, and the dissection of these factors is complex. Methods: The Swiss Kidney Stone Cohort (SKSC) is an investigator-initiated prospective, multi-centric longitudinal, observational study in patients with kidney stones followed with regular visits over a period of 3 years after inclusion. Ongoing follow-ups by biannual telephone interviews will provide long-term outcome data up to 10 years. Results: SKSC comprises 782 adult patients (age > 18 yrs) with either recurrent stones or a single stone event with at least one risk factor for recurrence. In addition, a control cohort of 207 individuals without kidney stone history and absence of kidney stones on a low-dose CT-scan at enrolment has also been recruited. SKSC includes extensive collections of clinical data, biochemical data in blood and 24 hr urine samples, and genetic data. Biosamples are stored at a dedicated biobank. Information on diet and dietary habits were collected through food frequency questionnaires and standardized recall interviews by trained dieticians with the Globodiet software. Conclusion: SKSC provides an unique opportunity and resource to further study cause and course of kidney disease in a large population with data and samples collected of a homogenous collective of patients throughout the whole Swiss population.