A feature article in the May issue of the British Medical Journal; Preventing over-diagnosis: how to stop harming the healthy, claims that asthma, among a list of other complaints, may be over-diagnosed.i A 2008 Canadian study found that almost 30% of people diagnosed as having asthma did not have the condition, and almost 66% of those did not need drugs or asthma care during six months of follow-up. ii
In the same year a Dutch study found that of 1,100 patients using inhaled corticosteroids, 30% may have been using the drugs without any clear indications. iii
Asthma can be severe so it is essential that a proper diagnosis be made. However, the BMJ article does raise the question if the high rates for asthma reported in New Zealand may in part be due to over-diagnosis. This was suggested in a paper presented by three of the world’s leading asthma researchers at the annual Thoracic Society conference in Auckland in 2007. While not suggesting people throw away their inhalers, they did suggest specific tests such as expired nitric oxide measurement, sputum analysis and CT scans to differentiate between asthma and other respiratory disorders. iv
Perhaps it is time to abandon asthma as a disease concept as suggested in a 2006 Lancet editorial. v The editorial board of this prestigious journal concluded it was best to abolish the term asthma altogether. Surely that can only be a good thing if it challenges researchers, doctors and their patients to re-examine the symptoms and consider treatment options besides the current default of increasingly more-potent asthma medications.
i BMJ 2012;344:e3502 doi: 10.1136/bmj.e3502 (Published 29 May 2012)
ii Aaron S, Vandemheen K, Boulet L, McIvor R, FitzGerald J, Hernandez P, et al. Overdiagnosis of asthma in obese and nonobese adults. CMAJ 2008;179:1121-31.
iii Lucas A, Smeenk F, Smeele I, van Schayck C. Overtreatment with inhaled corticosteroids and diagnostic problems in primary care patients, an exploratory study. Fam Pract 2008;25:86-91
iv Asthma misunderstood and misdiagnosed Thoracic society press release March 2007 http://www.scoop.co.nz/stories/GE0703/S00092.htm
v A plea to abandon asthma as a disease concept The Lancet, Volume 368, Issue 9537, Page 705, 26 August 2006