Bronchiectasis is a clinical syndrome where the most common symptom is a persistent or recurrent wet/productive cough.1,2 The diagnosis is confirmed objectively by identifying abnormally dilated bronchi with an increased broncho-arterial ratio (BAR) in a chest computed tomography (CT) scan.1,2 Globally, bronchiectasis is said to be the third most common chronic airway disorder,3,4 behind asthma and chronic obstructive pulmonary disease (COPD), and a leading cause of death and disability worldwide in adults.1,5 Indeed, adults with severe COPD may also have bronchiectasis,6 but this diagnosis is difficult to confirm without confirmation by a chest CT scan. Bronchiectasis has multiple aetiologies and affects all age groups and socio-economic classes in both high-income7–10 (HIC) and low-to-middle income countries5,11,12 (LMICs) and, for reasons that are uncertain, rates of disease and reported aetiology vary substantially in different populations.13 However, the burden of disease is greatest in socio-economically disadvantaged communities, including Indigenous populations in HICs.14

Importantly, in children with early, cylindrical bronchiectasis, symptoms can resolve and the abnormal bronchial dilatation may be reversed when an early diagnosis is made and optimal management is instituted.1,5,15,16 Also, there is increasing recognition that periconception, antenatal17 and early childhood factors, including chronic bronchitis (a component of bronchiectasis5), are mediators of future lung disease (e.g. COPD), poorer lung function and premature mortality in adults.18,19 Consequently, focusing upon children is important for reducing adult lung disease19,20 and preventing suboptimal lung function.21 To achieve this goal in bronchiectasis, its profile in children must be raised further to enable its prompt recognition and improved management by healthcare professionals.

Australian and English studies report many adults with bronchiectasis have symptoms from childhood.22,23 In the Australian study of 103 adults with bronchiectasis referred to a single centre, symptoms dating back to childhood were reported in 59% and associated with more severe disease (worse radiographic scores and poorer lung function) and worse prognosis than those whose symptoms began later in life.22 Their key symptom was chronic productive/wet cough and with its longer duration, the poorer the lung function, as reflected in lower forced expiratory volume in 1-second (FEV1) values (r −0.51, p<0.001 in non-smokers).22

Thus, to reduce the global burden of bronchiectasis, we need to concentrate not only upon established bronchiectasis, but also upon the recognition and evidence-based management of earlier symptoms. The most important is the identification of chronic wet/productive cough in children as early intervention may prevent progression, improve long-term outcomes and even reverse bronchial dilatation in those with mild disease.1,2,24 At the same time, the urgency of addressing the social determinants of health is also acknowledged.14

This review resulted from our Australian National Health Medical Research Council (NHMRC) Centre of Research Excellence (CRE) for child bronchiectasis (AusBREATHE) workshop. Here, we highlight the importance of prompt diagnosis and optimal management of bronchiectasis in children. We also discuss interventions exemplified by our research, with our RCTs undertaken in Australia, and in collaboration with others in New Zealand and South-East Asia (Malaysia, Philippines, Timor-Leste), in the hope that others in multiple different settings will undertake studies to address clinical knowledge gaps in this neglected field and improve the lives of people with bronchiectasis.

Despite the increased recognition of bronchiectasis1,5 and its known substantial morbidity5 and mortality,25 it remains a neglected lung disease26 with large unmet needs, especially in children.27,28 The importance of reducing the global burden of childhood bronchiectasis includes its disease burden, health inequity, and its links with future lung health.

Globally, the prevalence of bronchiectasis (67–1100 per 100,000 population29) is far higher than that of cystic fibrosis (CF) (1 in 3000 Caucasians, 1 in 4000–10,000 Latin Americans30).1 In addition to the prevalence burden, bronchiectasis also has a high patient-care burden,31 and high individual health needs28 and economic cost.5,27,32 In a systematic review, the annual healthcare cost for adults ranged in United States dollars (USD, standardised to 2021 USD) from USD3579 to 82,545 and indirect costs (e.g. lost income) ranged from USD1311 to 2898.32 The annual aggregate healthcare cost estimates varied from USD101.60 million in Singapore to USD14.68 billion in the United States, while in Australian children it was USD17.77 million.32 Respiratory exacerbations and hospitalisations33 drive these costs. In a prospective, multicentre cohort study of 85 children with bronchiectasis from Australia and New Zealand,31 mean exacerbations per child-year was 3.3 (standard deviation=2.2) with 11.4% of 264 episodes requiring hospitalisation. Absences from school or childcare due to bronchiectasis were 24.9 children per 100 child-months and quality-of-life (QoL) scores were negatively associated with cough severity.31

Reducing bronchiectasis is also important from a health equity perspective. On average, Australian Indigenous people with bronchiectasis die ∼22-years earlier than other Australians with bronchiectasis.25,34 This gap is substantially larger than for cardiovascular disease (where the gap is 9-years),25 yet bronchiectasis receives relatively little attention and resources, both clinically and in research. A large equity gap also exists within settings.35 A New Zealand study found that despite adolescents with bronchiectasis having significantly worse lung function than those with CF, they received less formalised transfer to adult services, and had fewer clinic appointments and resources available to them than patients with CF.36 An Australian specialist paediatric hospital study showed that children/adolescents with bronchiectasis have significantly and substantially poorer lung function than age-matched children/adolescents with CF (mean FEV1=78.6%predicted [standard deviation=20.5] vs 94.5%predicted [14.7] respectively), and received a lower standard of care (fewer clinic visits, physiotherapist reviews and lung function tests).35 These studies demonstrate the urgent need to improve detection, clinical management and equity of care so as to reduce the overall burden of bronchiectasis.

Our previous CRE37 was framed around a paradigm, which, if symptoms were left untreated, involved a continuous clinical spectrum linking protracted bacterial bronchitis (PBB) with initially reversible and then irreversible bronchiectasis.38 Subsequently, further data have consolidated this paradigm1,39 and it is now accepted globally.1,5,40,41 In our current CRE, we have expanded the paradigm (Fig. 1) to include modifiable risk factors of bronchiectasis. A focus on these antecedents is important, not only to reduce the burden of bronchiectasis, but also other chronic lung diseases and suboptimal lung development.

Fig. 1.

Our current paradigm that frames the work and studies underpinning our Centre of Research Excellence (AusBREATHE). The three themes address different parts of the paradigm, which are explained further in the text. The paradigm is framed around the notion that primary prevention of bronchiectasis is possible, and the knowledge that early detection of causal conditions substantially reduces the risk of developing bronchiectasis by the early initiation of treatment and optimal care. ALRIs, lower respiratory infections.

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Addressing the social determinants of health is a priority, but solving clinical issues in children is equally important given its impact upon lifetime health.18,19 Indeed, ignoring the clinical actions until social issues improve risks further disparity as this may take many years. Furthermore, which social interventions have most health impact is uncertain. A systematic overview of interventions addressing the social determinants of health found a striking lack of reliable evaluations.42 Therefore biomedical interventions and advances in healthcare remain essential and these require the best evidence available for preventing and managing illnesses.

To reduce the global burden of bronchiectasis, we need effective and feasible strategies for both primary and secondary prevention that will: (i) optimise early lung health and ameliorate illnesses impacting upon future lung function (e.g. acute lower respiratory infections [ALRIs]21); (ii) improve clinical outcomes of children with chronic cough (the most common symptom of lower airway infection and lung disease, including bronchiectasis1,5,43); and (iii) enhance outcomes of children with established (irreversible) bronchiectasis. As outlined in Fig. 1 and Table 1, our scientific strategies are based upon these themes. They are framed around the notion that primary prevention (Theme A) of bronchiectasis is possible and, its early detection (Theme B) (including causal conditions e.g. hypogammaglobulinemia) substantially reduces the risk of developing established bronchiectasis by promptly initiating optimal care. Many factors (yellow box, Fig. 1) influence progression of the illness and represent potential intervention points. Modifying factors affecting the prognosis of bronchiectasis require better clinical management and guideline implementation (Theme C).

The management and clinical outcomes of children with bronchiectasis have improved substantially. For example, the historical ‘destroyed lung’ described previously in Indigenous children85 is now rare and their lung function has recovered markedly.46,86 In the early 2000s, it was common to see lung function in children within the 30–60% predicted range at the time of receiving their bronchiectasis diagnosis.87 Currently, most Indigenous children with bronchiectasis that is managed optimally have lung function within the clinically normal range.46,86

Despite this progress, much more still needs to be done. We need resources to implement a plan to leverage what has been achieved by research to date. Globally, we also need to engage communities and their leaders to enable access and delivery of culturally appropriate care. Addressing social determinants of health in underserviced, disadvantaged populations remain an issue that needs specific on-going attention. Furthermore, there are many other potential contributors to disease (e.g. genetics, epigenetics, nutritional support, etc.) that are beyond the scope of our CRE and remit of our paper.

Disease-specific QoL tools are more sensitive than generic ones and are being considered increasingly as essential when evaluating health and intervention trials. QoL tools designed for adults are inappropriate for children.88 Since QoL measures are also considered the most important outcome for patients and parents of children with bronchiectasis,89 development of a paediatric bronchiectasis-specific QoL is now crucial. In addition, the priorities of parental needs and research priorities documented in an international survey28 should be used to guide research and clinical efforts to improve the lives of children with bronchiectasis and their families (Table 3).

Additional resources are needed for community consultation, patient care, healthcare systems and research to achieve equity with other chronic lung disorders (e.g. asthma, COPD, CF). Also, despite the known global burden of lung diseases, it receives proportionately less research funding and public attention than other important chronic diseases (e.g. cancer, cardiovascular disease, diabetes).90

Bronchiectasis is the third most common chronic airway disease, behind asthma and COPD.3 It affects all age groups and socioeconomic strata with the greatest burden in disadvantaged communities. Although bronchiectasis is most often diagnosed in older adults, more than half will have symptoms dating back to childhood.22,23 Furthermore, patients with symptoms from childhood have more advanced disease than those whose bronchiectasis only became apparent during their adult years.22,23 This is important, as bronchiectasis is potentially reversible in children when diagnosed early and treated optimally by multi-disciplinary healthcare teams. Timely treatment may also reduce the future bronchiectasis burden in adults.

Achieving these goals requires additional investment in (i) educating communities and healthcare professionals about the clinical significance of chronic wet/productive cough in children, (ii) funding research to identify modifiable proximal risk factors for bronchiectasis and design interventions that either prevent bronchiectasis developing or effectively managing it should it become established, and (iii) providing accessible and culturally-appropriate healthcare services to identify those at risk of bronchiectasis, and promptly diagnosing and treating those who have this chronic pulmonary disorder. We have focused on feasible strategies achievable within a short timeframe but there is also an on-going need to address complex issues (including social determinants) and other potential contributing factors (e.g. genetic and epigenetic associations). Finally, in this review, we have not focused on current management and instead refer readers to recent articles and existing guidelines (including their supplementary material) on the management of bronchiectasis in children/adolescents.1,2,24

The collective works reported are combined efforts of all the authors and their teams. AC conceptualised the framework and manuscript, and wrote the first draft which KG edited and then circulated to all (writing and extended groups) who amended the manuscript.

The workshop was supported by a National Health and Medical Research Council (NHMRC) Centre of Research Excellence (CRE) grant for paediatric bronchiectasis, especially in Aboriginal and Torres Strait Islanders grant (GNT1170958). ABC (L3, GNT2025379) and SCD are supported by NHMRC Investigator fellowships. JMM, STY and DFW are supported by NHMRC CRE (GNT1170958) fellowships. AS is supported by a Medical Research Future Fund (MRFF) Fellowship (APP1193796).

ABC, STY, SCD, KG, AS, PSM, MT, GBM and JMM report grants from the NHMRC and NHMRC managed grants (MRFF), Australia, during the conduct of the CRE. ABC is also an independent data management committee member for clinical trials for Moderna (COVID-19 vaccine) and of an unlicensed vaccine (GlaxoSmithKline), and monoclonal antibody (AstraZeneca), received fees to the institution for consulting on study designs for Zambon and Boehringer Ingelheim, and personal fees for being an author of two UpToDate chapters. SCD holds an investigator-initiated grant from GlaxoSmithKline and AstraZeneca for unrelated research. AS has received honoraria as advisory board member for Vertex Pharmaceuticals. All other authors have nothing to declare.