In NZ (as with several other parts of the world) there is currently a significant outbreak of pertussis in the population.
In the acute phase of pertussis/whooping cough, some NZ labs offer culture for Bordetella pertussis (with an overall sensitivity of 60-70%) and some offer PCR (with a sensitivity of approx. 90%).
So which is the better test? Purely in terms of efficacy, there is no comparison. (I know which test I would want…)
However the cost of a Bordetella pertussis culture is a few dollars, that of PCR 50-100 dollars. So which one is best now? I guess it depends to some extent on your agenda.
The point I am trying to make here is that the overall value of a test to the health service should not only be considered in terms of performance but also in its cost-effectiveness. There is only a fixed amount of money in the pot with a lot of different hands dipping in.
I am always intrigued by the amount of times I have sat in a conference listening to a speaker discuss a new assay or a new technology. Yet, most of the time, very little is said about the cost, skills required, and the other practicalities of implementing the test in a routine diagnostic lab. To omit such details is essentially only giving half the story and for me indicates somewhat of a detachment from the real world.
I think cost should always be considered when discussing any test. I like to think that microbiology scientists and clinical microbiologists know as much about money as managers do about microbiology.
p.s. For those that are interested I have added a short tutorial to the website on Hepatitis B serological markers, something that always confused me somewhat as a student!