It’s really common for a rheumatologist to see patients who present with a positive ANA result.
Sometimes, the test was performed for obscure reasons.
Almost always, the patient presents worried, particularly after a google search.
I had previously written of my approach to reassuring these worried people. Please read "ANA + does not = Lupus".
EVOLVE is an initiative of the Royal Australasian College of Physicians, based on the international ‘Choosing Wisely’ campaign, which seeks to get us doctors to consider which investigations, procedures, or interventions are overused, inappropriate, not based on evidence or just outdated.
Rheumatology has been asked to nominate their top five low value practices. It is a peer led process and my colleagues and I were recently asked to complete a survey, choosing from 12 potential items to vote for the top five.
I found this very useful and need to extend thanks to the project leaders from the Australian Rheumatology Association, Drs Catherine Hill, Nicola Cook and Rachelle Buchbinder for their time in coming up with these, as well as in reviewing the evidence for their selection. Many others were involved in working groups.
I thought it worth presenting some of these over the next few posts given they do make me, and other rheumatologists, think about our practices.
They are also very relevant to other doctors of course, especially general practitioners who would order the bulk of these tests.
The first recommendation I will highlight is:
Do not order ANA testing without symptoms and/or signs suggestive of a systemic rheumatic disease.
The available evidence shows that while ANA testing is useful in assisting in the confirmation or exclusion of systemic connective tissue disease, for example, Lupus, positive ANA are commonly present in many healthy individuals who do not have a disease.
An ANA titre of 1:40 occurs in 25-30% of the population, a titre of 1:80 occurs in 11-15% and a titre of 1:160 occurs in 5%.
I found the next figure quite astounding given Australia only has a population of about 24 million people.
“In 2014, more than 500,000 ANA tests were funded by the MBS at an annual cost of almost A$10.7 million in 2014 with an annual growth rate of 3.2% over the last decade.”
The majority of persons with a positive ANA do not have SLE. They just have mildly “abnormal” blood tests.
And this means that a positive ANA is only really useful in a person who has suggestive clinical features for a systemic connective tissue disease like lupus.
Another example of trying to choose wisely, and ordering a test for the right situation.