We may need to rethink asthma diagnosis and treatment.

A significant number of adults could be taking costly, unneeded asthma medication, a study published in the Journal of the American Medical Association this month suggests. 

Conducted by University of Ottawa researchers, the study found that a significant number of participants diagnosed with the chronic disease did not currently have asthma.

The research was conducted from January 2012 to February 2016 in ten Canadian cities. After a series of diagnostic tests on randomly selected asthmatic adults, the authors determined 12 of the 203 people (33 percent of 613) had other cardiorespiratory conditions and not asthma. The rest of the participants without current asthma did not have asthma at all or had asthma in remission, lead author Dr. Shawn Aaron told ResearchGate.

"We do understand why some cases of asthma become inactive," University of Washington School of Medicine clinical professor Dr. Reynold Karr, M.D. told ATTN: over email.

"In general, children with mild to moderate intermittent asthma often 'outgrow' the condition," Karr, an asthma and allergy specialist, added. "Although we do not know for sure why this occurs, it has been hypothesized that maturation of the airways may render them less labile. Changes in the human biome (skin, gut, airways) with age may play a role." Stocksy/Kelly Knox - stocksy.com

Participants who could not be diagnosed with current asthma or other respiratory conditions were tapered off asthma medication over a year and monitored in clinical and home exams. In a follow up study conducted a year later, over 90 percent of participants waned off medication did not present current asthma.

The findings suggest asthma is misunderstood and may be significantly over diagnosed and over treated as a result.

"Patients should make sure they get breathing tests (spirometry) done before they accept a diagnosis of asthma if they are having trouble breathing," Aaron said. "Secondly, if they have been diagnosed with asthma and are well-controlled (in other words, they are not having shortness of breath or wheezing or coughing) they should ask their doctor to reassess the diagnosis with spirometry and then decide whether they can try tapering asthma medication out. They should only do this with their doctor, not alone."

How often should you check on your asthma depends on the severity of the disease.

"There are four levels of asthma based on how severe it is," the Asthma and Allergy Foundation of America, a nonprofit organization, told ATTN: in an emailed statement.

From the AAFA:

• Intermittent Asthma — You have symptoms less than twice a week and wake up less than two nights a month.
• Mild Persistent Asthma — You have symptoms two or more days a week and wake up three to four nights a month.
• Moderate Persistent Asthma — You have symptoms at least every day and wake up one or more nights a week.
• Severe Persistent Asthma — You have symptoms during the day and wake up every night due to asthma.

"Mild to moderate disease under good control might require provider visits every 3-6 months, whereas severe disease under poor control may require frequent doctor visits, every 1-2 weeks," says Karr.

Karr agreed with Aaron and his co-authors recommendations and said he had encountered botched asthma diagnoses in practice and research.

"The problem definitely exists, and I concur with the authors’ recommendations which reflect our approach to asthma diagnosis and management," he said. "There are probably many reasons for the problem including primary care physicians’ effort to control healthcare cost by limiting diagnostic studies, patient compliance with physicians’ recommendations for diagnosis and management, and insurance coverage for care in the USA, to name a few."

The study does have some limitations.

A response to the media coverage posted on the UK's National Health Services blog reads: "Many people invited to take part did not do so, which means the participants may not be representative of the general population of people with asthma."  Though researchers asked for patient histories from participants doctors, not all the doctors provided diagnostic records, the NHS adds

That's not to discount the negative health and financial impacts of taking asthma treatment and medication you don't need.

"Health consequences of taking unneeded asthma medications consist of both short and long term side effects," Karr explained. "For example, corticosteroid use, especially with long term systemic moderate to high dose is associated with increased risk for a variety of metabolic side effects including osteoporosis, cataracts, hypertension, diabetes, and increased susceptibility to infection, to name a few. However, when appropriately used, benefits may be substantial with little long term risk when properly monitored." Corticosteroid medications are steroid hormones used to treat various lung conditions and can be taken orally or in a medicated inhaler.

Being misdiagnosed with asthma can cost a pretty penny — "an average of up to $1200 per year," according to Aaron. Lacking insurance access can make it astronomically pricier. In a 2013 New York Times piece, a family with two daughters with asthma and "good insurance" reported that they expected to spend about $1000 on medication that would have cost over $4000 without insurance.