A/Prof Subash Heraganahally

The overall bronchiectasis disease burden is higher in a cohort of Aboriginal Australians in the Top End than in international and non-Aboriginal Australian cohorts.

The shameful local data comes from 459 adult patients with chest CT-confirmed bronchiectasis diagnosed in the NT between 2011 and 2020. [link to cohort data in The MJA here]

Associate Professor Subash Heraganahally, director of respiratory and sleep medicine at the Royal Darwin Hospital, told TSANZSRS 2024 that Aboriginal Australians with bronchiectasis were younger compared to international bronchiectasis registry participants from Australia, Europe, India, Korea and the US.

Smoking rates were higher at 85% compared to other registry cohorts (22-46%). As well, comorbidities were more common: cardiovascular disease (43% v 4-32%); diabetes (50% v 6-14%) and COPD (83% v 14-37%).

Spirometry results showed a median FEV₁ of 38% predicted in Aboriginal Australians compared to 61-77% in other cohorts.

Sputum microbiology showed H. influenzae (57%) isolated at 3.4 – 6 times the rate of other registry cohorts.

Chest CT demonstrated multi-lobar and lower lobes involvement in 73% and inhaled pharmacotherapy use was recorded in 62% with long-term antibiotics in 5%.

Associate Professor Heraganahally told the limbic that the local prevalence of bronchiectasis in Aboriginal people at 19 per 1,000 was probably the highest reported in the world.

“This is probably underestimated … because we used CT scan, the gold standard for diagnosing bronchiectasis. To get a CT scan done in remote indigenous communities, some almost 1,000 kilometres away, is very difficult. So a lot of these patients would have bronchiectasis but they didn’t have an opportunity to undergo a CT scan.”

Also published recently in BMC Pulmonary Medicine [link here], was hospitalisation data showing 87% of the cohort had at least one respiratory-related hospitalisation during the 10-year period and an all-cause mortality rate of about 42%.

Patients who were hospitalised were older (57 v 53 years), had lower BMI (23 v 26 kg/m²), more concurrent COPD (88 v 47%), and lower spirometry values such as FVC (49 vs 63%) and FEV₁ (36 vs 55%) than those who did not have a hospitalisation.

He said comorbidities such as heart disease, kidney disease, diabetes and infections may be driving the high mortality rate as well.

A cost analysis of the hospitalisations is underway.

“One of the important interventions in bronchiectasis is chest physiotherapy. Just physiotherapy and sputum clearance techniques are proven beyond reasonable doubt to prevent hospital admission rates and mortality,” Associate Professor Heraganahally said.

“Ironically, a high income country like Australia doesn’t have a dedicated chest physiotherapist in the Northern Territory Top End … despite the fact that we’ve known for years that bronchiectasis is quite significant in this population.”

“In simple terms, if we had somebody who can treat some patients in the community with modalities which we know work, it’s actually going to reduce the hospital admission rate and save money. It’s simple common sense.”

The research was funded by the 2023 TSANZ Robert Pierce Grant-In-Aid for Indigenous Lung Health.

Read more on chronic lung disease in Indigenous Australians by Associate Professor Subash Heraganahally and colleagues in MJA InSight [link here].