gms | German Medical Science

Introduction: In Switzerland, solid organ donor evaluation and organ allocation have been organized at the level of all six transplant centers (Basel, Bern, Genf, Lausanne, St. Gallen and Zürich) since 1985. So far, the autonomy of the centers has hampered a systematic monitoring of the nationwide transplantation activities and relevant patient outcomes (e.g. mortality, graft loss). Furthermore, the realization of multi-centre studies concerning the post-transplant process was challenging to coordinate. Therefore, the Swiss Transplant Cohort Study (STCS) was originated in 2006 [1]. This prospective multi-centre study is designed as a dynamic cohort enrolling all solid organ recipients in Switzerland. The STCS enables a comprehensive monitoring of all countrywide transplantations and provides a structured, well-organized data administration allowing to conduct 'nested' multi-centre studies straightforwardly. The data base includes information about recipient and donor characteristics, infections diseases data and bio-banking. It is organized in a flexible patient-transplantation-organ level system reflecting the complex nature of the transplantation medicine. Additionally, the STCS psychosocial interest group was established to support the investigation of psychosocial, social-economic and behavioural factors. This is in contrast to other national cohort studies, e.g. the Scientific Registry of Transplant Recipients (SRTR) in the US or the Heidelberg-based Collaborative Transplant Study (CTS) in Europe focussing on specific biomedical questions.

Material: After a two-year set-up period, the STCS started with the enrolment of the first patients in May 2008. By August 2012, 1963 patients underwent 2019 transplantations with 2118 implanted organs [2]. Of them, 1833 (93.4%) patients have given their consent for an extensive data collection. Nevertheless, minimal data information are available for each recipient enrolled in the STCS, e.g. simple patient characteristics, blood group, cancer history, drug intake and donor information. This is attributed to the transplantation law in Switzerland started to be operative in 2007 which requires a mandatory life-long follow-up of all transplant recipients in Switzerland. Kidney transplantations (1127, 55.8%) predominate in the cohort followed by 413 (20.5%) liver and 192 (9.5%) lung transplantations. A total of 17 different transplantation scenarios have been observed so far. It is distinguished between single and multiple (with two or more organs) transplantations as well as between re- and second transplantations in case of repeated transplantations. After a baseline assessment at time of the first STCS transplantation, follow-up visits take place at six and twelve months and yearly thereafter. The current median follow-up duration is currently 1.9 years, 166 patients died, 120 had an allograft failure and six patients were lost to follow-up. Within the observation period, 5766 infection events occur in 1301 patients (66.3%).

Discussion: The STCS represents a promising project for comparative effectiveness research in transplantation medicine to evaluate the quality, effectiveness and efficiency of solid organ transplantations in order to support patients, health care professionals and policy makers with informed decision-making. Furthermore, it is an unique opportunity to investigate the benefit of different medical interventions within several transplantation scenarios. A total of 28 projects are currently running addressing research questions in immunology, skin cancer, genetics, infection diseases, psychosocial medicine and metabolism.