By its very nature, screening is characterised by administering a test to presymptomatic or early symptomatic individuals who may benefit from a more effective intervention if it is performed before the usual time of diagnosis.
Far from being a trivial intervention, screening can lead to significant consequences to the people screened. Therefore, before offering screening to workers, its effectiveness and the predominance of benefits over disadvantages must be demonstrated at the population level. Furthermore, screening should have the recommended characteristics in order that the expected benefits can be observed in practice.
Approaches using algorithms or flowcharts are generally meant to be sequential. Our approach had to be flexible and allow for compromises. The...