A new report into the use of spirometry in the diagnosis and management of chronic airways disease has highlighted “huge barriers” to access.
More than 80% of Australians with asthma and other airway conditions are missing out on recommended lung tests needed to properly diagnose their condition, according to the Australian Institute of Health and Welfare report produced by the Australian Centre for Airways disease Monitoring (ACAM) at the Woolcock Institute of Medical Research.
Woolcock respiratory physician Professor Helen Reddel told the limbic the results should not be seen as a criticism of GPs and physicians, but highlighted the barriers to access, including the lack of incentives and reimbursement, cost of equipment, ensuring staff were appropriately trained to administer the tests and time constraints.
“I don’t think it’s surprising that we’re seeing very low access levels for spirometry,” she told the limbic. “The issue of reimbursement has already been strongly discussed, but there is also the interpretation of the results that are an issue.”
Unlike tests for blood pressure and diabetes, which are absolutes, interpreting spirometry testing can be highly complex.
“There are no clear guidelines in spirometry – unlike in diabetes and hypertension where they are very clear – and that seems to me to be a perfect storm,” she said.
“There is no gold standard for asthma and there is a lot of variability in the diagnostic criteria for COPD,” she said. “There is more discussion going on in relation to guidelines and I think that is a positive thing.”
Spirometry lung function tests are recommended to ensure patients with breathing disorders are correctly diagnosed around the time they start medication.
However, the report showed a huge shortfall.
“We discovered that 82 per cent of people on medication to treat chronic airways disease, including asthma and chronic obstructive pulmonary disease (COPD), did not have their lung function tested within 12 months before or after their initial prescription,” Professor Reddel said.
“That is very concerning given research shows these tests are needed to ensure people are correctly diagnosed.”
The picture for asthma was particularly concerning. Once the disease is diagnosed, it is recommended that lung function be measured again periodically, every 1–2 years for most patients.
“But we found that lung function testing was performed for only about one-quarter of asthma patients in a three-year period, and 12 per cent had only one lung function test during that time,” Professor Reddel said.
“There are serious concerns the lack of testing may be contributing to inaccurate diagnosis and inappropriate use of medicines.”
She said there was a lot of research being done in Australia and overseas around the diagnosis of airway disease, and while this may lead to better ways, spirometry was the testing process currently recommended and doctors should access, either by doing it themselves or by outsourcing.
“There are a lot of conditions that can mimic asthma and COPD and we want to encourage having objective testing of lung function as part of the diagnostic process,” she said.
Professor Reddel is currently co-chairing a large international observational study, known as the NOVELTY study that aims to explore novel ways of classifying patients with obstructive lung disease according to clinical features, biomarkers and outcomes, to drive future insights and a better understanding of disease phenotypes and endotypes, and mechanisms of disease.
This project is in the process of enrolling patients across the whole spectrum of airways disease.
She has also published papers on the issue of guidelines, including a perspective last year in the Journal of Allergy and Clinical Immunology.
The AIHW report, The use of lung function testing for the diagnosis and management of chronic airways disease: Demonstration data linkage project using the 45 and Up Study 2001–2014, analysed data collected as part of Sax Institute’s 45 and Up Study of more than 250,000 NSW residents.