[Clustering of deaths at a work-place. Practical handling of a problem]

Clustering of deaths in a small, defined group of employees may occur by chance. Alternatively, the cause may be non-fortuitous, for example selection of risk individuals into the group, risk factors at work or in lifestyle. According to the Norwegian Working Environment Act it is the employer's duty to make the decision as to whether an observed cluster of deaths should have consequences for the working environment. The employer may feel a natural need for advice from specialists in order to take this decision. In many instances, the occupational health service will be a natural choice for the employer as a source of advice. At one work-place five out of a total of ten press consultants died between 1970 and 1988. The article describes a way to estimate the probability of the clustering being fortuitous. Fortuity is compared with other possibilities.