Developing spirometry and fractional exhaled nitric oxide (FeNO) reference values for Indigenous Australians: Phase II – adult Aboriginal and Torres Strait Islanders
Healthy Indigenous Lung Testing in Adults (HILTA)Lung diseases, the second most common chronic problems, are also major causes of death in Indigenous Australians. This is mostly due to higher incidence and severity of COPD, asthma and bronchiectasis. Intuitively, this situation would improve if these diseases had earlier diagnosis, optimal treatment, and monitoring.
Two standardised lung function tests that are used internationally to diagnose and monitor lung disease are spirometry and fractional exhaled nitric oxide (FeNO). Whilst both of these tests are performed by Indigenous Australians, interpreting the results is challenging because neither test has a reliable set of Indigenous adult reference values. Healthy reference values for both tests can be affected by ethnicity. Without correct reference values doctors are unable to accurately differentiate between normal healthy and abnormal results. Currently, many centres use Black African values which are up to 20% lower than Caucasian values. This risks missing important treatable lung disease. Reference ranges for respiratory function tests are determined by testing large numbers of non-smokers with no significant history/symptoms of respiratory disease.
Our study addresses the need for reference values for spirometry and FeNO tests in adult Indigenous Australians and will translate this data Australia-wide. We plan to perform spirometry and FeNO tests on 100-150 healthy non-smoking Indigenous adults in the Darwin region. The investigators have other funding to conduct the study in 3-4 Queensland communities (including HOT NORTH region of Thursday Island).
Additionally, the investigators have already collected valid data for Indigenous children and young adults in Northern Territory and Queensland. This paediatric data has been analysed and prepared for publication and dissemination. The adult data from this Darwin (HOT NORTH Round 6) and Queensland (to be collected in 2019) phase will be merged with paediatric data from NT and Qld to achieve directly translational all-age reference sets for spirometry and FeNO.