[Risk assessment in professional drivers with coronary heart disease: experiences with the evaluation program for locomotive drivers by the Swiss Federal Railroad 1986-1991].

BACKGROUND: For operational reasons in 1985 the question arose for the Swiss Federal Railways (SBB) whether engine-drivers (ED) with coronary heart disease (CHD) could be licensed for unaccompanied driving on certain well-defined premises. Until that year, such ED were allowed to drive only when accompanied by an apprentice ED. No generally accepted directives have operated in Switzerland for licensing ED or other professional drivers with CHD. METHODS: Based on data in the recent literature and assuming an acceptable mortality risk of about 0.75% per year, admission criteria were devised for licensing of ED with CHD for unaccompanied driving. Since 1986 every ED with CHD has been investigated according to these criteria by the medical service of the SBB in close cooperation with free practising and clinical cardiologists, and classified for driving alone, driving with accompaniment or as unfit to drive. ED who were fit to drive (either alone or accompanied) have checkups at least every three months by their family doctor and yearly by the medical service of the SBB and by a cardiologist for early recognition of any deterioration of their individual risk. RESULTS: From 1986-1991 a total of 114 ED were enrolled in the investigation program, 80 of whom proved to have CHD. 30 out of these 80 ED (37%) were cleared to drive alone at least for several months, 36 were licensed to drive with accompaniment for cardiac and non-cardiac reasons, and 14 were classified as unfit to drive. Among the ED driving without accompaniment, there was one death from heart failure during a total observation period of about 90 person-years, in an ED who had previously been re-classified for accompanied driving. One ED of the accompanied driving group died while on duty but not while driving. The annual incidence of new non-fatal CHD (non-fatal infarction, angina pectoris, ECG abnormality of proved coronary origin) was 0.25% in 1987 through 1991, for non-fatal infarction alone 0.14%. CONCLUSIONS: Our relatively restrictive licensing procedure served to identify an acceptable number of ED with CHD who could resume unrestricted work without compromising public safety in the short run. Framing of similar criteria for public service vehicle drivers is advocated.