Back in the day, blood tests relied on drawing blood from your vein and sending them back to the lab to get tested. While that is still the case for many people, newer technologies have developed to enable the blood drawn from a finger prick test to be used more and more. This has been especially useful in remote areas where electricity is scarce or no phlebotomist is available. Or, in wealthier nations, finger prick tests may be offered for patients who are scared of needles.
However a new study published in The American Journal of Clinical Pathology found that not every drop of blood from one person is the same:
Bioengineers at Rice University recently found that different drops from single fingerpricks on multiple subjects varied substantially on results for basic health measures like hemoglobin, white blood cell counts and platelet counts…
To get results as accurate as those achieved by the traditional method — inserting a needle into an arm vein — the investigators had to average the results of six to nine drops, said Rebecca Richards-Kortum, the director of Rice 360°: Institute for Global Health Technologies, which did the research.
So, if you want accuracy from your results, a venous draw is the best way, otherwise be aware that you will be sacrificing some accuracy with a finger prick test.
Watch the short video explanation from Rice University.
Not Every Drop of a Person’s Blood Is the Same, a Study Says | The New York Times