Australian research helps uncover a concerning type of cough in people with asthma

Why a high percentage of non-smokers with asthma experience a phlegmy, wet cough – symptoms more commonly associated with smoking-related lung disease – is a question that’s been investigated by researchers at the Woolcock Institute of Medical Research.

Research signals greater health issue than previously understood

Up to a third of Australians with asthma who have never smoked are coughing up mucus several or most days of the week, according to a new study.

The NOVELTY observational study recently published in the journal Respiratory Medicine looked at over 11,000 patients with asthma, chronic obstructive pulmonary disease (COPD) or both. It found that a phlegmy, wet cough (also called a productive cough), which is already a common symptom of smoking-related lung disease, is also affecting non-smokers with asthma.

Professor Helen Reddel, respiratory expert at the Woolcock Institute of Medical Research, Chair of the Global Initiative for Asthma (GINA) and International Co-chair of the NOVELTY study, says the findings show the problem is much bigger than has previously been identified, and that more research needs to look at why people with asthma also experience this cough.

“[Productive cough] is well-recognised as a symptom of smoking-related lung disease, but not much research has been done about it in people with asthma,” she said.

“It’s very important that we find out more about why this is occurring, because people who have a productive cough are more likely to experience a flare-up of their disease – such as an asthma attack – in the next 12 months than those who don’t.”

Professor Helen Reddel from the Woolcock Institute of Medical Research

The participants, who come from a mix of high- and middle-income nations, also showed some country-specific variation. Professor Reddel says the highest proportion of patients who had asthma and a productive cough were seen in the US, while Japan had the lowest rates.

Australia, which has a well-developed health system, fared well comparatively, but still had higher numbers of non-smokers coughing up phlegm or mucus three or more days a week over three months than researchers suspected.

“What is new in this study is that it has identified that this problem is also common in non-smokers, in people who have asthma rather than only in smoking-related lung disease.”

Professor Helen Reddel

“It’s a much bigger problem than has previously been identified.” 

The coughing, for which at present there is no specific treatment, has become particularly burdensome for patients in the era of COVID-19, where everyone is more sensitive to coughing in public, she says.

The study, which started about five years ago and therefore predated COVID-19, is continuing. Professor Reddel says it will be interesting to see if COVID-19 has any effects on upcoming results.

“We have one more visit by patients to come, so we will be able to see whether the prevalence [of the coughing] has changed since the pandemic,” she says.

“A key issue is to identify what factors are causing the cough and mucus, so that specific treatments can be developed.”

Community-led approach reducing rheumatic fever

A community-based research project in the Northern Territory is providing hope to remote communities in reducing rheumatic fever cases and the bacterial infections that trigger the condition.

Rheumatic fever, caused by household crowding and high rates of untreated streptococcal infections in children, can have devastating consequences, such as causing heart disease at a young age.

Community-driven activities key to success

The study – part of a 4-year collaboration with Menzies School of Health Research, Telethon Kids Institute, Sunrise Health Service and NT Health – focused on reducing household health risks through community-based activities led by Aboriginal Community Workers, in a bid to curb infection rates.

Housing and environmental health support – such as fixing showerheads, broken pipes and other health hardware – as well as information-sharing about rheumatic fever and assisting families to navigate healthcare, made up the focus of the activities.

This helped people gain the knowledge needed to seek medical treatment, which initially increased the number of reported infections. Because those infections were then able to be properly treated, rates of infection decreased to below baseline levels, especially in children.

Study co-author and Chairperson of the Board for Sunrise Health Service, Anne-Marie Lee, said the findings suggested the community-led activities translated into a reduction of the types of infection that drive rheumatic fever. The number of new cases of rheumatic fever also decreased during the study.

“Indigenous people working on the ground from that community, it works well. It doesn’t work if an outsider thinks that they can come in. You have to get local people on the ground to do the job,” Ms Lee said.

Director of RHDAustralia and Aboriginal advisor for the study, Ms Vicki Wade, agreed.

“It is so important for rheumatic fever control to be community-led. Rheumatic fever is fuelled by the socio-economic determinants of health, so that’s what we need to tackle, using scientifically based approaches that are co-designed in partnership with communities,” Ms Wade said.

Members of the research team together in Northern Territory, Australia
Members of the research team together in Northern Territory, Australia (L-R): Dr Vicki Kerrigan, Angela Kelly, Anne-Marie Lee, Segora Babui, Professor Anna Ralph, Valerina Mungatopi, Catherine Halkon

First of its kind study in Australia

Study lead and Senior Clinical Research Fellow at Menzies School of Health Research, Professor Anna Ralph, said rheumatic fever had declined in southern parts of Australia and globally in high income countries in the mid-1900s as standards of living improved – otherwise known as primordial prevention.

“Translating the key components of primordial prevention into tropical and central Australia requires innovation and strong partnerships,” Professor Ralph said.

“This is the first time Australian data has been published on the health impacts of community-led rheumatic fever primordial prevention. These findings are promising but need to be scaled up to whole communities.”

The research has been published in the International Journal of Environmental Research and Public Health and funded by the National Health and Medical Research Council, the National Heart Foundation and Bupa Foundation.