The screening of workers, or indeed of any members of the
population, for the presence of disease is an important issue which needs
to be critically considered, and never embarked upon lightly. It is worth
noting a few principles, relating to the value of and justification for
screening. The following questions should be asked before embarking on
a screening programme:
In an occupational context the most important preliminary questions
It is clear that any thoughtful person would pause before
introducing general health screening in a workforce if such questions were
considered. The chief disadvantage of 'health checks', apart from their
grossly inefficient use of resources, is the harm done to individuals when
insignificant findings lead to a series of unnecessary and sometimes dangerous
investigations. When screening a healthy workforce, such false positives
are likely greatly to outnumber true positives for whom useful intervention
What ill-health could be caused by working in this context?
Is everything reasonable being done to prevent this ill-health?
Should health surveillance therefore be undertaken
in relation to occupational ill-health?
ONLY once the above questions have been addressed, should one then
consider other screening issues that are not directly work-related:
Is the condition important for individuals or the community?
Is there effective treatment for/management of the condition?
Is the condition's natural history, especially its evolution
from latent to overt, understood?
Is there a recognisable latent or early stage?
Is there a valid and reproducible screening test?
Are facilities available for management of the positive
findings, both true or false?
Is there an agreed management policy?
Does this management favourably influence the course
of the disease?
Is the cost of case-finding and management acceptable
in relation to the overall costs of health care?
Do the potential benefits to true positives outweigh
the potential disadvantages for the false positives?
So-called 'executive medicals' are widely practised in
some sectors of industry. Good evidence that they constitute a cost effective
way of promoting health at work is lacking and one wonders whether they
are more of a status symbol whereby the recipient can demonstrate to colleagues
how highly he or she is prized by the organisation. Various reports, mainly
from North American companies, have suggested that initiatives to improve
lifestyle coupled with health screening appear to reduce the medical bills
for which the firms are responsible. However, there are hardly any well
designed and executed scientific studies that have measured the effectiveness
of health promotion in the workplace either in terms of improved health