Stefan graduated in General Medicine from the Comenius University in Bratislava, former Czechoslovakia, now the Slovak Republic, in 1981. He worked at the University Hospital Motol in Prague for 14 years and specialised in diagnostic radiology (both 1st and 2nd grades of specialisation). From 1993 to 1995 he worked as Head revision radiologist for the Czech Republic at the General Health Insurance Company (VZP) in Prague (part-time). In 1995 Stefan joined Pharma Industry (Nycomed, later acquired by GE Healthcare) and worked in Pharmacovigilance and Medical affairs departments of GE Healthcare in Oslo, Norway, and Amersham, UK, respectively, until 2016. At present, he is an independent consultant in Pharma industry.