Re: Methacholine test--is this the best/most accurate test for asthma?
From what I have read, it is the champ of asthma tests. Usually they don't use this test unless the other tests, such as the spirometry test were normal, but the doctor still suspected asthma.
It think it's about 88% accurate for positive results for asthma and 100% accurate for negative.
I might be wrong on those percentages but I think that it's close.
Re: Methacholine test--is this the best/most accurate test for asthma?
Tom,
Thanks for the super-fast reply. I was kindda thinking the same thing: this was the champ asthma test.
I am wondering if my primary dr can request this. My pulmonary dr, the last time I played around with the idea of the test, didn't think I needed it because my asthma is pretty mild.
Re: Methacholine test--is this the best/most accurate test for asthma?
A couple of comments - first of all, there can be false negatives (and false positives) with the methacholine challenge, so it's not a definitive test. One journal article I found calculated both the false negatives and false positives at about 5% of test participants.
A more important question is whether taking the test would change anything if you've already been diagnosed with asthma - the test is more likely to be helpful in inducing asthma in someone who doesn't have any symptoms but the doctor suspects has asthma. It's not a very pleasant test, and the whole point of the challenge is to induce asthma symptoms.
It sounds like you've already been diagnosed so, even if the test came back negative I suspect your doctor would recommend continuing whatever treatment you're on today (because the test isn't definitive) - typically if you have any history of asthma they're going to want you on a treatment regimen unless they find some other underlying condition that was causing the asthma.
Re: Methacholine test--is this the best/most accurate test for asthma?
I am hoping the test shares some light on the chest tightness I frequently experience--is it asthma or anxiety or both. I have had this two years. Since chest tightness overlaps anxiety and asthma, I have been wondering if this test will help me distinguish the feeling.
I have two prior pulmonolgoists question if I really have asthma since I don't wheeze and have the typical symptoms . My current pulm says I do. My feeling is I probably have it but because of the two other naysers drs I kind of hope I don't have asthma.
I thought of the test this past weekend. Saturday I did regular walking on level ground. A little after 30 minutes I felt slight shortness of breath. After 3 hits of albuterol and sitting down on park bench for 20 minutes I was good. My mind wonders (worries) if I will not be happered because of asthma from doing regular walking, and the test came to mind.