BMJ Open Respiratory Research最新文献

Objective: We aimed to elucidate the clinical factors associated with acute exacerbation and disease progression in young patients with chronic obstructive pulmonary disease (COPD).

Methods: This retrospective longitudinal observational study included patients with COPD aged between 20 and 50 years with post-bronchodilator forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC)<0.7. Eligible patients were followed up with ≥2 spirometry examinations at 1 year interval after COPD diagnosis. The primary outcome was moderate-to-severe acute exacerbation in young patients with COPD. Secondary outcomes were early initiation of regular inhalation therapy and accelerated annual post-bronchodilator FEV₁ decline.

Results: A total of 342 patients were followed up during a median of 64 months. In multivariable analyses, risk factors for moderate-to-severe exacerbation were history of asthma (adjusted HR (aHR)=2.999, 95% CI=[2.074-4.335]), emphysema (aHR=1.951, 95% CI=[1.331-2.960]), blood eosinophil count >300/µL (aHR=1.469, 95% CI=[1.038-2.081]) and low FEV₁ (%) (aHR=0.979, 95% CI=[0.970-0.987]). A history of asthma, sputum, blood eosinophil count >300/µL, low FEV₁ (%) and low diffusing capacity of the lung for carbon monoxide (DL_CO) (%) were identified as clinical factors associated with the early initiation of regular inhalation therapy. The risk factors associated with worsened FEV₁ decline were increasing age, female sex, history of pulmonary tuberculosis, sputum, low FEV₁ (%) and low DL_CO (%).

Conclusions: In young COPD patients, specific high-risk features of acute exacerbation and disease progression need to be identified, including a history of previous respiratory diseases, current respiratory symptoms, blood eosinophil counts, and structural or functional pulmonary impairment.

Background: High-flow nasal oxygen therapy (HFNO) is used in diverse hospital settings to treat patients with acute respiratory failure (ARF). This systematic review aims to summarise the evidence regarding any benefits HFNO therapy has compared with conventional oxygen therapy (COT) for patients with ARF.

Methods: Three databases (Embase, Medline and CENTRAL) were searched on 22 March 2023 for studies evaluating HFNO compared with COT for the treatment of ARF, with the primary outcome being hospital mortality and secondary outcomes including (but not limited to) escalation to invasive mechanical ventilation (IMV) or non-invasive ventilation (NIV). Risk of bias was assessed using the Cochrane risk-of-bias tool (randomised controlled trials (RCTs)), ROBINS-I (non-randomised trials) or Newcastle-Ottawa Scale (observational studies). RCTs and observational studies were pooled together for primary analyses, and secondary analyses used RCT data only. Treatment effects were pooled using the random effects model.

Results: 63 studies (26 RCTs, 13 cross-over and 24 observational studies) were included, with 10 230 participants. There was no significant difference in the primary outcome of hospital mortality (risk ratio, RR 1.08, 95% CI 0.93 to 1.26; p=0.29; 17 studies, n=5887) between HFNO and COT for all causes ARF. However, compared with COT, HFNO significantly reduced the overall need for escalation to IMV (RR 0.85, 95% CI 0.76 to 0.95 p=0.003; 39 studies, n=8932); and overall need for escalation to NIV (RR 0.70, 95% CI 0.50 to 0.98; p=0.04; 16 studies, n=3076). In subgroup analyses, when considering patients by illness types, those with acute-on-chronic respiratory failure who received HFNO compared with COT had a significant reduction in-hospital mortality (RR 0.58, 95% CI 0.37 to 0.91; p=0.02).

Discussion: HFNO was superior to COT in reducing the need for escalation to both IMV and NIV but had no impact on the primary outcome of hospital mortality. These findings support recommendations that HFNO may be considered as first-line therapy for ARF.

Prospero registration number: CRD42021264837.

Introduction: Pakistan has significantly strengthened its capacity for active case finding (ACF) for tuberculosis (TB) that is being implemented at scale in the country. However, yields of ACF have been lower than expected, raising concerns on its effectiveness in the programmatic setting. Distribution of TB in communities is likely to be spatially heterogeneous and targeting of ACF in areas with higher TB prevalence may help improve yields. The primary aim of SPOT-TB is to investigate whether a policy change to use a geographically targeted approach towards ACF supported by an artificial intelligence (AI) software, MATCH-AI, can improve yields in Pakistan.

Methods and analysis: SPOT-TB will use a pragmatic, stepped wedge cluster randomised design. A total of 30 mobile X-ray units and their field teams will be randomised to receive the intervention. Site selection for ACF in the intervention areas will be guided primarily through the use of MATCH-AI software that models subdistrict TB prevalence and identifies potential disease hotspots. Control areas will use existing approaches towards site selection that are based on staff knowledge, experience and analysis of historical data. The primary outcome measure is the difference in bacteriologically confirmed incident TB detected in the intervention relative to control areas. All remaining ACF-related procedures and algorithms will remain unaffected by this trial.

Ethics and dissemination: Ethical approval has been obtained from the Health Services Academy, Islamabad, Pakistan (7-82/IERC-HSA/2022-52) and from the Common Management Unit for TB, HIV and Malaria, Ministry of Health Services, Regulation and Coordination, Islamabad, Pakistan (26-IRB-CMU-2023). Findings from this study will be disseminated through publications in peer-reviewed journals and stakeholder meetings in Pakistan with the implementing partners and public-sector officials. Findings will also be presented at local and international medical and public health conferences.

Trial registration number: NCT06017843.

Background: Asthma is a heterogeneous disease with a prevalence and severity that differs between male and female patients.

Question: What are differences between male and female patients with asthma with regard to asthma control, lung function, inflammation and exacerbations?

Methods: We performed a post hoc analysis in the ATLANTIS (Assessment of Small Airways Involvement in Asthma) study, an observational cohort study including patients with asthma from nine countries with a follow-up of 1 year during which patients were characterised with measures of large and small airway function, questionnaires, inflammation and imaging. We compared differences in baseline characteristics and longitudinal outcomes between male and female patients with asthma.

Results: 773 patients were enrolled; 450 (58%) of these were female. At baseline, female patients with asthma were in higher Global Initiative for Asthma (GINA) steps (p=0.042), had higher Asthma Control Questionnaire 6 (F: 0.83; M: 0.66, p<0.001) and higher airway resistance as reflected by uncorrected impulse oscillometry outcomes (ie, R₅-R₂₀: F: 0.06; M: 0.04 kPa/L/s, p=0.002). Male patients with asthma had more severe airway obstruction (forced expiratory volume in 1 s/forced vital capacity % predicted: F: 91.95; M: 88.33%, p<0.01) and more frequently had persistent airflow limitation (F: 27%; M: 39%, p<0.001). Blood neutrophils were significantly higher in female patients (p=0.014). With Cox regression analysis, female sex was an independent predictor for exacerbations.

Interpretation: We demonstrate that female patients are in higher GINA steps, exhibit worse disease control, experience more exacerbations and demonstrate higher airway resistance compared with male patients. The higher exacerbation risk was independent of GINA step and blood eosinophil level. Male patients, in turn, have a higher prevalence of persistent airflow limitation and more severe airflow obstruction. These findings show sex can affect clinical phenotyping and outcomes in asthma.

Trial registration number: NCT02123667.

Background: Closed-loop oxygen control systems automatically adjust the fraction of inspired oxygen (FiO₂) to maintain oxygen saturation (SpO₂) within a predetermined target range. Their performance with low and high-flow oxygen therapies, but not with non-invasive ventilation, has been established. We compared the effect of automated oxygen on achieving and maintaining a target SpO₂ range with nasal high flow (NHF), bilevel positive airway pressure (bilevel) and continuous positive airway pressure (CPAP), in stable hypoxaemic patients with chronic cardiorespiratory disease.

Methods: In this open-label, three-way cross-over trial, participants with resting hypoxaemia (n=12) received each of NHF, bilevel and CPAP treatments, in random order, with automated oxygen titrated for 10 min, followed by 36 min of standardised manual oxygen adjustments. The primary outcome was the time taken to reach target SpO₂ range (92%-96%). Secondary outcomes included time spent within target range and physiological responses to automated and manual oxygen adjustments.

Results: Two participants were randomised to each of six possible treatment orders. During automated oxygen control (n=12), the mean (±SD) time to reach target range was 114.8 (±87.9), 56.6 (±47.7) and 67.3 (±61) seconds for NHF, bilevel and CPAP, respectively, mean difference 58.3 (95% CI 25.0 to 91.5; p=0.002) and 47.5 (95% CI 14.3 to 80.7; p=0.007) seconds for bilevel and CPAP versus NHF, respectively. Proportions of time spent within target range were 68.5% (±16.3), 65.6% (±28.7) and 74.7% (±22.6) for NHF, bilevel and CPAP, respectively.Manually increasing, then decreasing, the FiO₂ resulted in similar increases and then decreases in SpO₂ and transcutaneous carbon dioxide (PtCO₂) with NHF, bilevel and CPAP.

Conclusion: The target SpO₂ range was achieved more quickly when automated oxygen control was initiated with bilevel and CPAP compared with NHF while time spent within the range across the three therapies was similar. Manually changing the FiO₂ had similar effects on SpO₂ and PtCO₂ across each of the three therapies.

Trial registration number: ACTRN12622000433707.

Background: Existing studies on chronic obstructive pulmonary disease (COPD) in Korea lack full population coverage, relying on small sample sizes. Therefore, this study aims to investigate the prevalence and mortality of COPD in the entire Korean population.

Methods: This serial cross-sectional study used national databases, linking the National Health Information Database (2008-2017) with Causes of Death Statistics. Identification of individuals with COPD used diagnostic codes (International Classification of Diseases-10: J41-J44) or a history of COPD-related hospitalisation, focusing on adults aged 40 and above. Prevalence and mortality rates, calculated for 2008-2017, encompassed both crude and age-standardised and sex-standardised measures. A multivariate Poisson regression model estimated the association between COPD and all-cause and cause-specific mortality, presenting incidence rate ratios (IRRs) and 95% CIs, using data from the year 2017.

Results: Age-adjusted COPD prevalence exhibited a notable increase from 2008 (7.9%) to 2017 (16.7%) in both sexes. The prevalences of diabetes mellitus, hypertension, dyslipidaemia, ischaemic heart disease, cancer, osteoporosis and tuberculosis were higher in the COPD group than in the group without COPD (p for all <0.001). The incidence of stroke and myocardial infarction (p for all <0.001) and overall mortality were higher in the COPD group (adjusted IRR 1.23, 95% CI 1.22 to 1.24, p<0.001). In particular, incidence rate and risk of mortality due to lung cancer were higher than that of those without COPD compared with other cancer types (adjusted IRR 2.51, 95% CI 2.42 to 2.60, p<0.001). It was significantly higher the incidence rate and risk of mortality among group with COPD than those without COPD in lower respiratory disease (adjusted IRR 16.62, 95% CI 15.07 to 18.33, p<0.001), asthma (adjusted IRR 6.41, 95% CI 5.47 to 7.51, p<0.001) and bronchiectasis (adjusted IRR 11.77, 95% CI 7.59 to 18.26, p<0.001), respectively.

Discussion: Our study showed that the prevalence of COPD is gradually increasing from 9.2% in 2009 to 16.7% in 2018. Furthermore, in overall (all-cause) mortality, it was significantly higher in group with COPD than in group without COPD. The mortality rate of group with COPD was much higher than the overall mortality rate but is gradually decreasing.

Background: Herpes zoster (HZ) is a painful condition caused by reactivation of the varicella-zoster virus. The objectives of this study were to compare HZ incidence in adults with asthma versus adults without asthma and to compare healthcare resource use as well as direct costs in adults with HZ and asthma versus adults with asthma alone in the USA.

Methods: This retrospective longitudinal cohort study included adults aged ≥18 years across the USA. Patients were identified from Optum's deidentified Clinformatics Data Mart Database, an administrative claims database, between 1 October 2015 and 28 February 2020, including commercially insured and Medicare Advantage with part D beneficiaries. Cohorts of patients with and without asthma, and separate cohorts of patients with asthma and HZ and with asthma but not HZ, were identified using International Classification of Diseases 10th Revision, Clinical Modification codes. HZ incidence, healthcare resource use and costs were compared, adjusting for baseline characteristics, between the relevant cohorts using generalised linear models.

Results: HZ incidence was higher in patients with asthma (11.59 per 1000 person-years) than patients without asthma (7.16 per 1000 person-years). The adjusted incidence rate ratio (aIRR) for HZ in patients with asthma, compared with patients without asthma, was 1.34 (95% CI 1.32 to 1.37). Over 12 months of follow-up, patients with asthma and HZ had more inpatient stays (aIRR 1.11; 95% CI 1.02 to 1.21), emergency department visits (aIRR 1.26; 95% CI 1.18 to 1.34) and outpatient visits (aIRR 1.19; 95% CI 1.16 to 1.22), and direct healthcare costs that were US dollars ($) 3058 (95% CI $1671 to $4492) higher than patients with asthma without HZ.

Conclusion: Patients with asthma had a higher incidence of HZ than those without asthma, and among patients with asthma HZ added to their healthcare resource use and costs.

Objective: This study aims to explore the common genetic basis between respiratory diseases and to identify shared molecular and biological mechanisms.

Methods: This genome-wide pleiotropic association study uses multiple statistical methods to systematically analyse the shared genetic basis between five respiratory diseases (asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, lung cancer and snoring) using the largest publicly available genome wide association studies summary statistics. The missions of this study are to evaluate global and local genetic correlations, to identify pleiotropic loci, to elucidate biological pathways at the multiomics level and to explore causal relationships between respiratory diseases. Data were collected from 27 November 2022 to 30 March 2023 and analysed from 14 April 2023 to 13 July 2023.

Main outcomes and measures: The primary outcomes are shared genetic loci, pleiotropic genes, biological pathways and estimates of genetic correlations and causal effects.

Results: Significant genetic correlations were found for 10 paired traits in 5 respiratory diseases. Cross-Phenotype Association identified 12 400 significant potential pleiotropic single-nucleotide polymorphism at 156 independent pleiotropic loci. In addition, multitrait colocalisation analysis identified 15 colocalised loci and a subset of colocalised traits. Gene-based analyses identified 432 potential pleiotropic genes and were further validated at the transcriptome and protein levels. Both pathway enrichment and single-cell enrichment analyses supported the role of the immune system in respiratory diseases. Additionally, five pairs of respiratory diseases have a causal relationship.

Conclusions and relevance: This study reveals the common genetic basis and pleiotropic genes among respiratory diseases. It provides strong evidence for further therapeutic strategies and risk prediction for the phenomenon of respiratory disease comorbidity.