[rrsp]

For context Rheumatoid Factor is present in 4% of the healthy population, an even upto 30% in certain populations like native Americans [1]

ANA is positive in 15% of the population [2]

The idea that the tests rule out serious causes is not really correct, people can have seronegative inflammatory arthritis in which case these tests are negative. Peace of mind is dubious as well given that even with a positive test you are still more likely to not have an inflammatory arthritis.

It’s a common misconception that blood tests are binary and provide concrete answers. Sometimes they do. But most blood tests, like many measurements, are far from binary and have a distribution across the normal population, once it passes an arbitrary threshold it does not necessarily mean you have disease X, context (clinical history and examination) are often far more important in making a diagnosis.

Unfortunately some of the population tend to overweight blood tests vs a physicians assessment, I guess they see the former as an objective measure and the latter as subjective. Especially because if you shop around enough clinicians you’ll eventually find one who will say what you want to hear and that one will inevitably be ‘right’.

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3845430/ 2. https://rheumatology.org/patients/antinuclear-antibodies-ana...

[y-c-o-m-b]

Thanks for the information. I've been diagnosed with seronegative inflammatory arthritis myself, so I understand that the blood tests are not perfect; and "rule out" was used loosely to mean "unlikely to have". All of which is not really relevant to my point. My point was that health practitioners have become too comfortable with using anxiety (without evidence) to brush off patient concerns instead of utilizing cheap diagnostic tests to aide in the exploratory process of diagnosing a patient accurately.

In the case of my wife, once both blood tests came back positive, she was properly referred to a rheumatologist to continue monitoring her symptoms and their progression. That is how the healthcare system is supposed to work. Run tests, if it comes back positive, keep investigating with the right specialists that are more experienced in the area, then continue to look for signals that a diagnosis is accurate. Not this hand-wavy speculation with lack of evidence we experienced early on. Now that she has started to develop rheumatoid nodules, it's becoming more accepted by her healthcare team that this is rheumatoid arthritis.