Prospective Swiss cohort study of living-kidney donors: study protocol

BACKGROUND: Offering living kidney donation raised the concern that donors are exposed to unknown risks. All Swiss transplant centres therefore decided to start a prospective cohort study of living kidney donors in Switzerland. This paper describes the rationale for and implementation of this cohort study. METHODS/DESIGN: All kidney donors in Switzerland are registered and examined before donation and biennially after donation starting in the first year after nephrectomy. Before each follow-up visit, the study centre sends a package to the kidney donor containing the health questionnaire, blood and urine tubes and a prepaid envelope for sending the samples to the central laboratory. The donor makes an appointment with their family physician, who examines the donor and reports findings such as pain and other complaints, blood pressure, creatinine, albumin, all major health events and the state of mental and social well-being to the study centre. The family doctor draws the blood sample and mails it with the urine sample in the prepaid envelope. All data are centrally managed. All abnormal findings in the follow-up of individual donors are regularly discussed with the principal investigator, and necessary clinical changes made and recorded in the database. The health insurance of the recipient covers all costs of the donor follow-up. The main outcomes are the occurrence of albuminuria, hypertension and renal insufficiency. The secondary outcomes are major somatic and social events such as death, cardiovascular disease, stroke and depression. DISCUSSION: This prospective cohort offers unique opportunities to assess the risks of living kidney donation and will allow us to examine the risks associated with the methods used for nephrectomy in Switzerland (various forms of open surgery and laparoscopic nephrectomy). The prospective collection of all clinically relevant data and the regular monitoring of donors will allow timely interventions at early stages before serious kidney and general health problems occur.