Prevalence and burden of difficult-to-treat and severe asthma in Australia: A national population survey.

BACKGROUND AND OBJECTIVE: Most evidence about difficult-to-treat and severe asthma (DTTA) comes from clinical trials and registries. We aimed to identify people with DTTA from a large nationally representative asthma population and describe their characteristics and healthcare utilization compared with people whose asthma was not 'difficult-to-treat'. METHODS: We conducted a cross-sectional survey of Australians aged ≥18 years with current asthma from large web-based survey panels. Enrolment was stratified by gender, age-group and state/territory based on national population data for people with asthma. Difficult-to-treat or severe asthma was defined by poor symptom control, exacerbations and/or oral corticosteroid/biologic use despite medium/high-dose inhaled therapy. Outcomes included exacerbations, healthcare utilization, multimorbidity, quality of life and coronavirus disease of 2019 (COVID-19)-related behaviour. Weighted data were analysed using SAS version 9.4. RESULTS: The survey was conducted in February-March 2021. The weighted sample comprised 6048 adults with current asthma (average age 47.3 ± SD 18.1 years, 59.9% female), with 1313 (21.7%) satisfying ≥1 DTTA criteria. Of these, 50.4% had very poorly controlled symptoms (Asthma Control Test ≤15), 36.2% were current smokers, and 85.4% had ≥1 additional chronic condition, most commonly anxiety/depression. More than twice as many participants with DTTA versus non-DTTA had ≥1 urgent general practitioner (GP) visit (61.4% vs. 27.5%, OR 4.8 [4.2-5.5, p < 0.0001]), or ≥1 emergency room visit (41.9% vs. 17.9%, OR 3.8 [3.3-4.4, p < 0.0001]) in the previous 12 months. CONCLUSION: Our findings emphasize the burden of uncontrolled symptoms, current smoking, multimorbidity and healthcare utilization in people with DTTA in the community, who may be under-represented in registries or clinical trials.

COPD in Never-Smokers: BOLD Australia Study.

Purpose: Tobacco smoking is the major risk factor for COPD, and it is common for other risk factors in never-smokers to be overlooked. We examined the prevalence of COPD among never-smokers in Australia and identified associated risk factors. Methods: We used data from the Australia Burden of Obstructive Lung Disease (BOLD) study, a cross-section of people aged ≥40 years from six sites. Participants completed interviews and post-bronchodilator spirometry. COPD was primarily defined as an FEV1/FVC ratio <0.70 and secondarily as the ratio less than the lower limit of normal (LLN). Results: The prevalence of COPD in the 1656 never-smokers who completed the study was 10.5% (95% CI: 9.1-12.1%) [ratio

Smoking behaviour, tobacco sales and tobacco advertising at 40 'Smoke Free Hospitals' in Vietnam.

BACKGROUND: Tobacco remains the leading cause of preventable death globally. Vietnam's 2012 Law on Prevention and Control of Tobacco Harms establishes all healthcare facilities as smoke-free environments. We aimed to evaluate the implementation of these policies within health facilities across Vietnam. METHODS: A cross-sectional study was undertaken at 40 central, provincial, district and commune healthcare facilities in four provinces of Vietnam. The presence of tobacco sales, smoke-free signage, evidence of recent tobacco use and smoking behaviours by patients and staff were observed over a 1-week period at multiple locations within each facility. Adherence with national regulations was reported using descriptive statistics. RESULTS: 23 out of 40 facilities (57.5%) followed the requirements of the national smoke-free policy regarding tobacco sales, advertising and signage. Smoking was observed within health facility grounds at 26 (65%) facilities during the observation period. Indirect evidence of smoking was observed at 35 (88%) facilities. Sites where smoking was permitted (n=2) were more likely to have observed smoking behaviour (relative risk (RR) 2.16, 95% CI 1.83 to 2.56). Facilities where tobacco was sold (n=7) were more likely to have smoking behaviour observed at any of their sites (RR 1.53, 95% CI 0.93 to 2.51). CONCLUSIONS: Implementation of current smoke-free hospital regulations remains incomplete, with widespread evidence of smoking observed at three levels of the Vietnamese healthcare facilities. Further interventions are required to establish the reputation of Vietnamese healthcare facilities as smoke-free environments.

"It's like a forgotten issue sometimes ": Qualitative study of individuals living and caring for people with chronic breathlessness.

INTRODUCTION: This study aims to explore the perspectives of patients and carers with chronic breathlessness on current provision of care, care expectations, and self-management needs to develop relevant health services and resources to improve clinical outcomes. METHODS: In-depth semistructured interviews were conducted on patients living with chronic breathlessness and carers. RESULTS: Thirteen patients (cardiac, respiratory, and noncardiorespiratory) and two carers were interviewed (mean age 57 years, 47% female, median duration with breathlessness 5 years). Four main themes were identified: (1) living with breathlessness, (2) diagnosis delays, misdiagnosis, and knowledge gaps, (3) beyond curing disease: symptom relief and improving quality of life, and (4) self-management and limited support for it. CONCLUSION: Breathlessness has a high personal impact but remains a neglected condition in Australia. Patients suffer from lack of personal, community, and provider awareness, discontinuity of care, and too few clinical and self-management options.

A smoking quitline integrated with clinician counselling at outpatient health facilities in Vietnam: a single-arm prospective cohort study.

BACKGROUND: Limited evidence is available about the combination of multiple smoking cessation modalities in low- and middle-income countries. The study aimed to assess the feasibility of a smoking cessation intervention that integrates follow-up counselling phone calls and scheduled text messages with brief advice from physicians in Vietnam. METHODS: This was a single-arm intervention study. Smokers were referred to the study Quitline after brief advice by physicians at three rural district hospitals in Hanoi, Vietnam. Following referral, participants received nine counselling phone calls in 12 months and a scheduled text message service that lasted for three months. Participants who reported smoking cessation for at least 30 days at the 12-month follow-up were invited for a urinary cotinine test to confirm cessation. RESULTS: The Quitline centre had 431 referrals from participating hospitals. Among them, 221 (51.3%) were enrolled. After the baseline phone call, 141 (63.8%) participated in all 4 follow-up calls within the first month and 117 (52.9%) participated in all phone calls in 12 months. The median number of successful phone calls was 8 (interquartile range: 6 - 8). At the end of the study, 90 (40.7%) self-reported abstinence from smoking over the previous 30 days. Among them, 22 (24.4%) submitted a sample for cotinine test, of which 13 (59.1% of those tested) returned a negative result. The proportion of biochemically-verified quitters was 5.9%. CONCLUSIONS: The integration of brief advice and referral from healthcare facilities, Quitline counselling phone calls, and scheduled text messaging was feasible in rural health facilities in northern Vietnam. TRIAL REGISTRATION: ACTRN12619000554167 .

Estimating the long-term effects of mass screening for latent and active tuberculosis in the Marshall Islands.

BACKGROUND: Ambitious population-based screening programmes for latent and active tuberculosis (TB) were implemented in the Republic of the Marshall Islands in 2017 and 2018. METHODS: We used a transmission dynamic model of TB informed by local data to capture the Marshall Islands epidemic's historical dynamics. We then used the model to project the future epidemic trajectory following the active screening interventions, as well as considering a counterfactual scenario with no intervention. We also simulated future scenarios including periodic interventions similar to those previously implemented, to assess their ability to reach the End TB Strategy targets and TB pre-elimination in the Marshall Islands. RESULTS: The screening activities conducted in 2017 and 2018 were estimated to have reduced TB incidence and mortality by around one-third in 2020, and are predicted to achieve the End TB Strategy milestone of 50% incidence reduction by 2025 compared with 2015. Screening interventions had a considerably greater impact when latent TB screening and treatment were included, compared with active case finding alone. Such combined programmes implemented at the national level could achieve TB pre-elimination around 2040 if repeated every 2 years. CONCLUSIONS: Our model suggests that it would be possible to achieve TB pre-elimination by 2040 in the Marshall Islands through frequent repetition of the same interventions as those already implemented in the country. It also highlights the importance of including latent infection testing in active screening activities.

Behaviors and Attitudes Toward Smoking Among Health Care Workers at Health Facilities in 4 Provinces of Vietnam: A Representative Cross-Sectional Survey.

Tobacco smoking is a leading cause of premature death. Smoking prevalence in Vietnam ranks among the highest in Southeast Asia. Given the important role of health care workers (HCWs) in promoting and supporting smoking cessation, this project aimed to characterize the prevalence of smoking among HCWs in Vietnam, and their attitudes toward smoking cessation interventions. A cross-sectional survey was conducted among care workers in four levels of the health system, within four provinces of Vietnam. Descriptive statistics evaluated participant attitudes, perception, behaviors, and knowledge about smoking. Multivariable logistic regression models evaluated risk factors for smoking. Among 3343 HCWs, 7.5% identified as current smokers, comprising 22.2% males and 0.5% of females. Males had substantially greater odds (adjusted odds ratio = 55.3; 95% confidence interval [29.0, 105.6] of identifying as current smokers compared with females. HCWs in urban settings had higher odds of identifying as smokers compared with rural workers (adjusted odds ratio = 1.72; 95% confidence interval [1.23, 2.24]. Strong support for smoking cessation policies and interventions were identified, even among staff who smoked. HCWs play an integral role in identifying smokers and supporting smoking cessation interventions for their patients. Efforts to support affordable smoking cessation interventions within health facilities are likely to contribute to a reduction in smoking prevalence in Vietnam.

Normal limits for oscillometric bronchodilator responses and relationships with clinical factors.

INTRODUCTION: We aimed to determine normal thresholds for positive bronchodilator responses for oscillometry in an Australian general population sample aged ≥40 years, to guide clinical interpretation. We also examined relationships between bronchodilator responses and respiratory symptoms, asthma diagnosis, smoking and baseline lung function. METHODS: Subjects recruited from Sydney, Melbourne and Busselton, Australia, underwent measurements of spirometry, resistance (R rs6 ) and reactance (X rs6 ) at 6 Hz, before and after inhalation of salbutamol 200 µg. Respiratory symptoms and/or medication use, asthma diagnosis, and smoking were recorded. Threshold bronchodilator responses were defined as the fifth percentile of decrease in R rs6 and 95th percentile increase in X rs6 in a healthy subgroup. RESULTS: Of 1318 participants, 1145 (570 female) were analysed. The lower threshold for ΔR rs6 was -1.38 cmH2O·s·L-1 (-30.0% or -1.42 Z-scores) and upper threshold for ΔX rs6 was 0.57 cmH2O·s·L-1 (1.36 Z-scores). Respiratory symptoms and/or medication use, asthma diagnosis, and smoking all predicted bronchodilator response, as did baseline oscillometry and spirometry. When categorised into clinically relevant groups according to those predictors, ΔX rs6 was more sensitive than spirometry in smokers without current asthma or chronic obstructive pulmonary disease (COPD), ∼20% having a positive response. Using absolute or Z-score change provided similar prevalences of responsiveness, except in COPD, in which responsiveness measured by absolute change was twice that for Z-score. DISCUSSION: This study describes normative thresholds for bronchodilator responses in oscillometry parameters, including intra-breath parameters, as determined by absolute, relative and Z-score changes. Positive bronchodilator response by oscillometry correlated with clinical factors and baseline function, which may inform the clinical interpretation of oscillometry.

Chronic airflow obstruction and ambient particulate air pollution.

Smoking is the most well-established cause of chronic airflow obstruction (CAO) but particulate air pollution and poverty have also been implicated. We regressed sex-specific prevalence of CAO from 41 Burden of Obstructive Lung Disease study sites against smoking prevalence from the same study, the gross national income per capita and the local annual mean level of ambient particulate matter (PM2.5) using negative binomial regression. The prevalence of CAO was not independently associated with PM2.5 but was strongly associated with smoking and was also associated with poverty. Strengthening tobacco control and improved understanding of the link between CAO and poverty should be prioritised.

Smoking behaviour among adult patients presenting to health facilities in four provinces of Vietnam.

BACKGROUND: Attendance at healthcare facilities provides an opportunity for smoking cessation interventions. However, the smoking behaviours of patients seeking healthcare in Vietnam are not well-understood. We aimed to evaluate behaviours related to smoking among patients presenting to health facilities in Vietnam. METHODS: We conducted a cross-sectional study in 4 provinces of Vietnam. Consecutive patients aged ≥15 years presenting to 46 health facilities were assessed. Current smokers were randomly selected to complete a full survey about smoking behaviour, quit attempts, and preparedness to quit. RESULTS: Among 11,245 patients who sought healthcare, the prevalence of current smoking was 18.6% (95% CI: 17.8-19.4%) overall, 34.6% (95% CI: 33.2-36.0%) among men and 1.1% (95% CI: 0.8-1.3%) among women. Current smokers who were asked about smoking by healthcare providers in the last 12 months were more likely to make quit attempts than those not asked (40.6% vs 31.8%, p = 0.017). Current smokers who attempted to quit in the past 12 months made limited use of cessation aids: counselling (1.9%) and nicotine replacement therapy (10%). A higher proportion of patients wanted to quit in the next month at national/provincial hospitals (30.3%) than those visiting district hospitals (11.3%, p < 0.001) and commune health centres (11.1%, p = 0.004). CONCLUSIONS: Smoking is common among male patients presenting to healthcare facilities in Vietnam. Formal smoking cessation supports are generally not used or offered. This population is likely to benefit from routine smoking cessation interventions that are integrated within the routine healthcare delivery system.

Treatable Traits in Elderly Asthmatics from the Australasian Severe Asthma Network: A Prospective Cohort Study.

BACKGROUND: Data on treatable traits (TTs) in different populations are limited. OBJECTIVE: To assess TTs in elderly patients with asthma and compare them to younger patients, to evaluate the association of TTs with future exacerbations, and to develop an exacerbation prediction model. METHODS: We consecutively recruited 521 participants at West China Hospital, Sichuan University based on the Australasian Severe Asthma Network, classified as elderly (n = 62) and nonelderly (n = 459). Participants underwent a multidimensional assessment to characterize the TTs and were then followed up for 12 months. TTs and their relationship with future exacerbations were described. Based on the TTs and asthma control levels, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort. RESULTS: A total of 38 TTs were assessed. Elderly patients with asthma had more chronic metabolic diseases, fixed airflow limitation, emphysema, and neutrophilic inflammation, whereas nonelderly patients with asthma exhibited more allergic characteristics and psychiatric diseases. Nine traits were associated with increased future exacerbations, of which exacerbation prone, upper respiratory infection-induced asthma attack, cardiovascular disease, diabetes, and depression were the strongest. A model including exacerbation prone, psychiatric disease, cardiovascular disease, upper respiratory infection-induced asthma attack, noneosinophilic inflammation, cachexia, food allergy, and asthma control was developed to predict exacerbation risk and showed good performance. CONCLUSIONS: TTs can be systematically assessed in elderly patients with asthma, some of which are associated with future exacerbations, proving their clinical utility of evaluating them. A model based on TTs can be used to predict exacerbation risk in people with asthma.

Sputum TNF markers are increased in neutrophilic and severe asthma and are reduced by azithromycin treatment.

BACKGROUND: The AMAZES randomized controlled trial demonstrated that long-term low-dose azithromycin treatment reduces exacerbations of poorly controlled asthma, but the therapeutic mechanisms remain unclear. Dysregulation of the inflammatory tumour necrosis factor (TNF) pathway is implicated in asthma and could be suppressed by azithromycin. We aimed to determine the inflammatory and clinical associations of soluble TNF signalling proteins (TNF receptors [TNFR] 1 and 2, TNF) in sputum and serum, and to test the effect of 48 weeks of azithromycin vs placebo on TNF markers. METHODS: Sputum supernatant and serum TNFR1, TNFR2 (n = 142; 75 azithromycin-treated, 67 placebo-treated) and TNF (n = 48; 22 azithromycin-treated, 26 placebo-treated) were measured by ELISA in an AMAZES trial sub-population at baseline and end of treatment. Baseline levels were compared between sputum inflammatory phenotypes, severe/non-severe asthma and frequent/non-frequent exacerbators. Effect of azithromycin on markers was tested using linear mixed models. RESULTS: Baseline sputum TNFR1 and TNFR2 were significantly increased in neutrophilic vs non-neutrophilic asthma phenotypes, while serum markers did not differ. Sputum TNFR1 and TNFR2 were increased in severe asthma and correlated with poorer lung function, worse asthma control and increasing age. Serum TNFR1 was also increased in severe asthma. Sputum and serum TNFR2 were increased in frequent exacerbators. Azithromycin treatment significantly reduced sputum TNFR2 and TNF relative to placebo, specifically in non-eosinophilic participants. CONCLUSIONS: We demonstrate dysregulation of TNF markers, particularly in the airways, that relates to clinically important phenotypes of asthma including neutrophilic and severe asthma. Suppression of dysregulated TNF signalling by azithromycin could contribute to its therapeutic mechanism.

Identifying preventable risk factors for hospitalised asthma in young Aboriginal children: a whole-population cohort study.

BACKGROUND: Australia has one of the highest rates of asthma worldwide. Indigenous children have a particularly high burden of risk determinants for asthma, yet little is known about the asthma risk profile in this population. AIM: To identify and quantify potentially preventable risk factors for hospitalised asthma in Australian Aboriginal children (1-4 years of age). METHODS: Birth, hospital and emergency data for all Aboriginal children born 2003-2012 in Western Australia were linked (n=32 333). Asthma was identified from hospitalisation codes. ORs and population attributable fractions were calculated for maternal age at birth, remoteness, area-level disadvantage, prematurity, low birth weight, maternal smoking in pregnancy, mode of delivery, maternal trauma and hospitalisations for acute respiratory tract infection (ARTI) in the first year of life. RESULTS: There were 705 (2.7%) children hospitalised at least once for asthma. Risk factors associated with asthma included: being hospitalised for an ARTI (OR 4.06, 95% CI 3.44 to 4.78), area-level disadvantage (OR 1.58, 95% CI 1.28 to 1.94), being born at <33 weeks' gestation (OR 3.30, 95% CI 2.52 to 4.32) or birth weight <1500 g (OR 2.35, 95% CI 1.39 to 3.99). The proportion of asthma attributable to an ARTI was 31%, area-level disadvantage 18%, maternal smoking 5%, and low gestational age and birth weight were 3%-7%. We did not observe a higher risk of asthma in those children who were from remote areas. CONCLUSION: Improving care for pregnant Aboriginal women as well as for Aboriginal infants with ARTI may help reduce the burden of asthma in the Indigenous population.

Prevalence and Population-Attributable Risk for Chronic Airflow Obstruction in a Large Multinational Study.

Rationale: The Global Burden of Disease program identified smoking and ambient and household air pollution as the main drivers of death and disability from chronic obstructive pulmonary disease (COPD). Objectives: To estimate the attributable risk of chronic airflow obstruction (CAO), a quantifiable characteristic of COPD, due to several risk factors. Methods: The Burden of Obstructive Lung Disease study is a cross-sectional study of adults, aged ≥40, in a globally distributed sample of 41 urban and rural sites. Based on data from 28,459 participants, we estimated the prevalence of CAO, defined as a postbronchodilator FEV1-to-FVC ratio less than the lower limit of normal, and the relative risks associated with different risk factors. Local relative risks were estimated using a Bayesian hierarchical model borrowing information from across sites. From these relative risks and the prevalence of risk factors, we estimated local population attributable risks. Measurements and Main Results: The mean prevalence of CAO was 11.2% in men and 8.6% in women. The mean population attributable risk for smoking was 5.1% in men and 2.2% in women. The next most influential risk factors were poor education levels, working in a dusty job for ≥10 years, low body mass index, and a history of tuberculosis. The risk of CAO attributable to the different risk factors varied across sites. Conclusions: Although smoking remains the most important risk factor for CAO, in some areas, poor education, low body mass index, and passive smoking are of greater importance. Dusty occupations and tuberculosis are important risk factors at some sites.

Risk Factors for Tuberculosis (TB) Among Household Contacts of Patients With Smear-Positive TB in 8 Provinces of Vietnam: A Nested Case-Control Study.

BACKGROUND: Tuberculosis (TB) continues to account for significant morbidity and mortality annually. Household contacts (HHCs) of persons with TB are a key population for targeting prevention and control interventions. We aimed to identify risk factors associated with developing TB among HHCs. METHODS: We conducted a nested case-control study among HHCs in 8 provinces in Vietnam enrolled in a randomized controlled trial of active case finding for TB. Cases were any HHCs diagnosed and registered with TB within the Vietnam National TB Program during 2 years of follow-up. Controls were selected by simple random sampling from the remaining HHCs. Risk factor data were collected at enrollment and during follow-up. A logistic regression model was developed to determine predictors of TB among HHCs. RESULTS: We selected 1254 HHCs for the analysis: 214 cases and 1040 controls. Underlying characteristics varied between both groups; cases were older, more likely to be male, with a higher proportion of reported previous TB and diabetes. Risk factors associated with a TB diagnosis included being male (adjusted odds ratio [aOR], 1.4; 95% confidence interval [CI], 1.03-2.0), residing in an urban setting (aOR, 1.8; 1.3-2.5), prior TB (aOR, 4.6; 2.5-8.7), history of diabetes (aOR, 3.1; 1.7-5.8), current smoking (aOR, 3.1; 2.2-4.4), and prolonged history of coughing in the index case at enrollment (OR , 1.6; 1.1-2.3). CONCLUSIONS: Household contacts remain an important key population for TB prevention and control. TB programs should ensure effective contact investigations are implemented for household contacts, particularly those with additional risk factors for developing TB.