Large-scale phenotyping of patients with long COVID post-hospitalization reveals mechanistic subtypes of disease.

One in ten severe acute respiratory syndrome coronavirus 2 infections result in prolonged symptoms termed long coronavirus disease (COVID), yet disease phenotypes and mechanisms are poorly understood1. Here we profiled 368 plasma proteins in 657 participants ≥3 months following hospitalization. Of these, 426 had at least one long COVID symptom and 233 had fully recovered. Elevated markers of myeloid inflammation and complement activation were associated with long COVID. IL-1R2, MATN2 and COLEC12 were associated with cardiorespiratory symptoms, fatigue and anxiety/depression; MATN2, CSF3 and C1QA were elevated in gastrointestinal symptoms and C1QA was elevated in cognitive impairment. Additional markers of alterations in nerve tissue repair (SPON-1 and NFASC) were elevated in those with cognitive impairment and SCG3, suggestive of brain-gut axis disturbance, was elevated in gastrointestinal symptoms. Severe acute respiratory syndrome coronavirus 2-specific immunoglobulin G (IgG) was persistently elevated in some individuals with long COVID, but virus was not detected in sputum. Analysis of inflammatory markers in nasal fluids showed no association with symptoms. Our study aimed to understand inflammatory processes that underlie long COVID and was not designed for biomarker discovery. Our findings suggest that specific inflammatory pathways related to tissue damage are implicated in subtypes of long COVID, which might be targeted in future therapeutic trials.

Temporal Risk of Nonfatal Cardiovascular Events After Chronic Obstructive Pulmonary Disease Exacerbation: A Population-based Study.

Rationale: Cardiovascular events after chronic obstructive pulmonary disease (COPD) exacerbations are recognized. Studies to date have been post hoc analyses of trials, did not differentiate exacerbation severity, included death in the cardiovascular outcome, or had insufficient power to explore individual outcomes temporally.Objectives: We explore temporal relationships between moderate and severe exacerbations and incident, nonfatal hospitalized cardiovascular events in a primary care-derived COPD cohort.Methods: We included people with COPD in England from 2014 to 2020, from the Clinical Practice Research Datalink Aurum primary care database. The index date was the date of first COPD exacerbation or, for those without exacerbations, date upon eligibility. We determined composite and individual cardiovascular events (acute coronary syndrome, arrhythmia, heart failure, ischemic stroke, and pulmonary hypertension) from linked hospital data. Adjusted Cox regression models were used to estimate average and time-stratified adjusted hazard ratios (aHRs).Measurements and Main Results: Among 213,466 patients, 146,448 (68.6%) had any exacerbation; 119,124 (55.8%) had moderate exacerbations, and 27,324 (12.8%) had severe exacerbations. A total of 40,773 cardiovascular events were recorded. There was an immediate period of cardiovascular relative rate after any exacerbation (1-14 d; aHR, 3.19 [95% confidence interval (CI), 2.71-3.76]), followed by progressively declining yet maintained effects, elevated after one year (aHR, 1.84 [95% CI, 1.78-1.91]). Hazard ratios were highest 1-14 days after severe exacerbations (aHR, 14.5 [95% CI, 12.2-17.3]) but highest 14-30 days after moderate exacerbations (aHR, 1.94 [95% CI, 1.63-2.31]). Cardiovascular outcomes with the greatest two-week effects after a severe exacerbation were arrhythmia (aHR, 12.7 [95% CI, 10.3-15.7]) and heart failure (aHR, 8.31 [95% CI, 6.79-10.2]).Conclusions: Cardiovascular events after moderate COPD exacerbations occur slightly later than after severe exacerbations; heightened relative rates remain beyond one year irrespective of severity. The period immediately after an exacerbation presents a critical opportunity for clinical intervention and treatment optimization to prevent future cardiovascular events.

Cause-specific mortality in COPD subpopulations: a cohort study of 339 647 people in England.

BACKGROUND: Identifying correlates of cause-specific mortality in patients with chronic obstructive pulmonary disease (COPD) may aid the targeting of therapies to reduce mortality. We determined factors associated with causes of death in a primary care COPD population. METHODS: Clinical Practice Research Datalink Aurum was linked to Hospital Episode Statistics and death certificate data. People with COPD alive between 1 January 2010 and 1 January 2020 were included. Patient characteristics were defined before the start of follow-up: (a) frequency and severity of exacerbations; (b) emphysema or chronic bronchitis; (c) Global Obstructive Lung Disease (GOLD) groups A-D; and (d) airflow limitation. We used Cox Proportional Hazards regression and competing risks to investigate the association between patient characteristics and risk of all-cause, COPD and cardiovascular (CV) mortality. RESULTS: 339 647 people with COPD were included of which 97 882 died during follow-up (25.7% COPD related and 23.3% CV related). Airflow limitation, GOLD group, exacerbation frequency and severity, and COPD phenotype were associated with all-cause mortality. Exacerbations, both increased frequency and severity, were associated with COPD-related mortality (≥2 exacerbations vs none adjusted HR: 1.64, 1.57-1.71; 1 severe vs none adjusted HR: 2.17, 2.04-2.31, respectively). Patients in GOLD groups B-D had a higher risk of COPD and CV mortality compared with GOLD group A (GOLD group D vs group A, adjusted HR for COPD mortality: 4.57, 4.23-4.93 and adjusted HR for CV mortality: 1.53, 1.41-1.65). Increasing airflow limitation was also associated with both COPD and CV mortality (GOLD 4 vs 1, adjusted HR: 12.63, 11.82-13.51 and adjusted HR: 1.75, 1.60-1.91, respectively). CONCLUSION: Poorer airflow limitation, worse functional status and exacerbations had substantial associations with risk of all-cause mortality. Differing results for CV and COPD-related mortality suggests interventions to prevent mortality may need to target particular characteristics or time points in the disease course.

Incidence, prevalence and mortality of idiopathic pulmonary fibrosis in England from 2008 to 2018: a cohort study.

BACKGROUND: Owing to discrepancies in methodologies and how idiopathic pulmonary fibrosis (IPF) is diagnosed it is challenging to establish a consistent understanding of the disease burden In the UK, over 10 years ago, the incidence and prevalence of IPF were reported as 2.8-8.7 per 100 000 person-years (from 2000 to 2012) and 39 per 100 000 persons (in 2012), respectively. Here, we estimated the incidence and prevalence of IPF in England from 2008 to 2018 and investigated IPF mortality. METHODS: Using Clinical Practice Research Datalink Aurum and Hospital Episode Statistics (HES) linked datasets, we estimated incidence and prevalence using four validated diagnostic-code-based algorithms. Using the registered number of deaths (from Office of National Statistics) with the underlying cause being recorded as IPF, we estimated IPF mortality for the same period. RESULTS: Using Aurum-based definitions, incidence increased over time by 100% for Aurum narrow (3-6.1 per 100 000 person-years) and by 25% for Aurum broad (22.4-28.6 per 100 000 person-years). However, using HES-based definitions showed a decrease in incidence over the same period and lay between the two extremes derived for Aurum-based definition. IPF mortality in 2018 was 7.9 per 100 000 person-years and increased by 53% between 2008 and 2018. INTERPRETATION: When using best-case definitions, incidence rose throughout the study period. Scaling this to England's population (2018), our best estimate would be in the range of 8000-9000 new cases per year which is higher than previously reported estimates (5000-6000). This increased burden in the new cases of IPF each year impacts future health service planning and resource allocation.

Association between socioeconomic deprivation, ethnicity and health outcomes in preschool children with recurrent wheeze in England: a retrospective cohort study.

BACKGROUND: Preschool-aged children have among the highest burden of acute wheeze. We investigated differences in healthcare use, treatment and outcomes for recurrent wheeze/asthma in preschoolers from different ethno-socioeconomic backgrounds. METHODS: Retrospective cohort study using data from the Clinical Practice Research Datalink linked to Hospital Episode Statistics in England. We reported number of acute presentations and hospitalisations stratified by index of multiple deprivation (IMD) and ethnicity; and factors associated with treatment non-escalation, and hospitalisation rates using multivariable logistic and Poisson regression models. RESULTS: 194 291 preschool children were included. In children not trialled on asthma preventer medications, children from the most deprived IMD quintile (adjusted OR 1.67; 95% CI 1.53 to 1.83) and South Asian (1.77; 1.64 to 1.91) children were more likely to have high reliever usage and where specialist referral had not occurred, the odds of referral being indicated was higher in the most deprived quintile (1.39; 1.28 to 1.52) and South Asian (1.86; 1.72 to 2.01) children compared with the least deprived quintile and white children, respectively.Hospitalisation rates for wheeze/asthma were significantly higher in children from the most deprived quintile (adjusted IRR 1.20; 95% CI 1.13 to 1.27) compared with the least, and in South Asian (1.57; 1.44 to 1.70) and black (1.32; 1.22 to 1.42) compared with white children. CONCLUSIONS: We identified inequalities in wheeze/asthma treatment and morbidity in preschool children from more deprived, and non-white backgrounds. A multifaceted approach to tackle health inequality at both the national and local levels, which includes a more integrated and standardised approach to treatment, is needed to improve health outcomes in children with preschool wheeze/asthma.

Rheumatoid arthritis and idiopathic pulmonary fibrosis: a bidirectional Mendelian randomisation study.

BACKGROUND: A usual interstitial pneumonia (UIP) pattern of lung injury is a key feature of idiopathic pulmonary fibrosis (IPF) and is also observed in up to 40% of individuals with rheumatoid arthritis (RA)-associated interstitial lung disease (RA-ILD). The RA-UIP phenotype could result from either a causal relationship of RA on UIP or vice versa, or from a simple co-occurrence of RA and IPF due to shared demographic, genetic or environmental risk factors. METHODS: We used two-sample bidirectional Mendelian randomisation (MR) to test the hypothesis of a causal effect of RA on UIP and of UIP on RA, using variants from genome-wide association studies (GWAS) of RA (separately for seropositive (18 019 cases and 991 604 controls) and seronegative (8515 cases and 1 015 471 controls) RA) and of IPF (4125 cases and 20 464 controls) as genetic instruments. Sensitivity analyses were conducted to assess the robustness of the results to violations of the MR assumptions. FINDINGS: IPF showed a significant causal effect on seropositive RA, with developing IPF increasing the risk of seropositive RA (OR=1.06, 95% CI: 1.04 to 1.08, p<0.001) which was robust under all models. For the MR in the other direction, seropositive RA showed a significant protective effect on IPF (OR=0.93; 95% CI: 0.87 to 0.99; p=0.032), but the effect was not significant when sensitivity analyses were applied. This was likely because of bias due to exclusion of patients with RA from among the cases in the IPF GWAS, or possibly because our genetic instruments did not fully capture the effect of the complex human leucocyte antigen region, the strongest RA genetic risk factor. INTERPRETATION: Our findings support the hypothesis that RA-UIP may be due to a cause-effect relationship between UIP and RA, rather than due to a coincidental occurrence of IPF in patients with RA. The significant causal effect of IPF on seropositive RA suggests that pathomechanisms involved in the development of UIP may promote RA, and this may help inform future guidelines on screening for ILD in patients with RA.

Greenhouse gas emissions associated with suboptimal asthma care in the UK: the SABINA healthCARe-Based envirONmental cost of treatment (CARBON) study.

BACKGROUND: Poorly controlled asthma is associated with increased morbidity and healthcare resource utilisation (HCRU). Therefore, to quantify the environmental impact of asthma care, this retrospective, cohort, healthCARe-Based envirONmental cost of treatment (CARBON) study estimated greenhouse gas (GHG) emissions in the UK associated with the management of well-controlled versus poorly controlled asthma. METHODS: Patients with current asthma (aged ≥12 years) registered with the Clinical Practice Research Datalink (2008‒2019) were included. GHG emissions, measured as carbon dioxide equivalent (CO2e), were estimated for asthma-related medication use, HCRU and exacerbations during follow-up of patients with asthma classified at baseline as well-controlled (<3 short-acting ß2-agonist (SABA) canisters/year and no exacerbations) or poorly controlled (≥3 SABA canisters/year or ≥1 exacerbation). Excess GHG emissions due to suboptimal asthma control included ≥3 SABA canister prescriptions/year, exacerbations and any general practitioner and outpatient visits within 10 days of hospitalisation or an emergency department visit. RESULTS: Of the 236 506 patients analysed, 47.3% had poorly controlled asthma at baseline. Scaled to the national level, the overall carbon footprint of asthma care in the UK was 750 540 tonnes CO2e/year, with poorly controlled asthma contributing excess GHG emissions of 303 874 tonnes CO2e/year, which is equivalent to emissions from >124 000 houses in the UK. Poorly controlled versus well-controlled asthma generated 3.1-fold higher overall and 8.1-fold higher excess per capita carbon footprint, largely SABA-induced, with smaller contributions from HCRU. CONCLUSIONS: These findings suggest that addressing the high burden of poorly controlled asthma, including curbing high SABA use and its associated risk of exacerbations, may significantly alleviate asthma care-related carbon emissions.

Combination of BAL and Computed Tomography Differentiates Progressive and Non-progressive Fibrotic Lung Diseases.

Rationale: Identifying patients with pulmonary fibrosis (PF) at risk of progression can guide management. Objectives: To explore the utility of combining baseline BAL and computed tomography (CT) in differentiating progressive and nonprogressive PF. Methods: The derivation cohort consisted of incident cases of PF for which BAL was performed as part of a diagnostic workup. A validation cohort was prospectively recruited with identical inclusion criteria. Baseline thoracic CT scans were scored for the extent of fibrosis and usual interstitial pneumonia (UIP) pattern. The BAL lymphocyte proportion was recorded. Annualized FVC decrease of >10% or death within 1 year was used to define disease progression. Multivariable logistic regression identified the determinants of the outcome. The optimum binary thresholds (maximal Wilcoxon rank statistic) at which the extent of fibrosis on CT and the BAL lymphocyte proportion could distinguish disease progression were identified. Measurements and Main Results: BAL lymphocyte proportion, UIP pattern, and fibrosis extent were significantly and independently associated with disease progression in the derivation cohort (n = 240). Binary thresholds for increased BAL lymphocyte proportion and extensive fibrosis were identified as 25% and 20%, respectively. An increased BAL lymphocyte proportion was rare in patients with a UIP pattern (8 of 135; 5.9%) or with extensive fibrosis (7 of 144; 4.9%). In the validation cohort (n = 290), an increased BAL lymphocyte proportion was associated with a significantly lower probability of disease progression in patients with nonextensive fibrosis or a non-UIP pattern. Conclusions: BAL lymphocytosis is rare in patients with extensive fibrosis or a UIP pattern on CT. In patients without a UIP pattern or with limited fibrosis, a BAL lymphocyte proportion of ⩾25% was associated with a lower likelihood of progression.

Factors associated with non-fatal heart failure and atrial fibrillation or flutter within the first 30 days post COPD exacerbation: a nested case-control study.

BACKGROUND: An immediate, temporal risk of heart failure and arrhythmias after a Chronic Obstructive Pulmonary Disease (COPD) exacerbation has been demonstrated, particularly in the first month post-exacerbation. However, the clinical profile of patients who develop heart failure (HF) or atrial fibrillation/flutter (AF) following exacerbation is unclear. Therefore we examined factors associated with people being hospitalized for HF or AF, respectively, following a COPD exacerbation. METHODS: We conducted two nested case-control studies, using primary care electronic healthcare records from the Clinical Practice Research Datalink Aurum linked to Hospital Episode Statistics, Office for National Statistics for mortality, and socioeconomic data (2014-2020). Cases had hospitalization for HF or AF within 30 days of a COPD exacerbation, with controls matched by GP practice (HF 2:1;AF 3:1). We used conditional logistic regression to explore demographic and clinical factors associated with HF and AF hospitalization. RESULTS: Odds of HF hospitalization (1,569 cases, 3,138 controls) increased with age, type II diabetes, obesity, HF and arrhythmia history, exacerbation severity (hospitalization), most cardiovascular medications, GOLD airflow obstruction, MRC dyspnea score, and chronic kidney disease. Strongest associations were for severe exacerbations (adjusted odds ratio (aOR)=6.25, 95%CI 5.10-7.66), prior HF (aOR=2.57, 95%CI 1.73-3.83), age≥80 years (aOR=2.41, 95%CI 1.88-3.09), and prior diuretics prescription (aOR=2.81, 95%CI 2.29-3.45). Odds of AF hospitalization (841 cases, 2,523 controls) increased with age, male sex, severe exacerbation, arrhythmia and pulmonary hypertension history and most cardiovascular medications. Strongest associations were for severe exacerbations (aOR=5.78, 95%CI 4.45-7.50), age≥80 years (aOR=3.15, 95%CI 2.26-4.40), arrhythmia (aOR=3.55, 95%CI 2.53-4.98), pulmonary hypertension (aOR=3.05, 95%CI 1.21-7.68), and prescription of anticoagulants (aOR=3.81, 95%CI 2.57-5.64), positive inotropes (aOR=2.29, 95%CI 1.41-3.74) and anti-arrhythmic drugs (aOR=2.14, 95%CI 1.10-4.15). CONCLUSIONS: Cardiopulmonary factors were associated with hospitalization for HF in the 30 days following a COPD exacerbation, while only cardiovascular-related factors and exacerbation severity were associated with AF hospitalization. Understanding factors will help target people for prevention.

Relationship between asthma and severe COVID-19: a national cohort study.

BACKGROUND: We aimed to determine whether children and adults with poorly controlled or more severe asthma have greater risk of hospitalisation and/or death from COVID-19. METHODS: We used individual-level data from the Office for National Statistics Public Health Data Asset, based on the 2011 census in England, and the General Practice Extraction Service data for pandemic planning and research linked to death registration records and Hospital Episode Statistics admission data. Adults were followed from 1 January 2020 to 30 September 2021 for hospitalisation or death from COVID-19. For children, only hospitalisation was included. RESULTS: Our cohort comprised 35 202 533 adults and 2 996 503 children aged 12-17 years. After controlling for sociodemographic factors, pre-existing health conditions and vaccine status, the risk of death involving COVID-19 for adults with asthma prescribed low dose inhaled corticosteroids (ICS) was not significantly different from those without asthma. Adults with asthma prescribed medium and high dosage ICS had an elevated risk of COVID-19 death; HRs 1.18 (95% CI 1.14 to 1.23) and 1.36 (95% CI 1.28 to 1.44), respectively. A similar pattern was observed for COVID-19 hospitalisation; fully adjusted HRs 1.53 (95% CI 1.50 to 1.56) and 1.52 (95% CI 1.46 to 1.56) for adults with asthma prescribed medium and high-dosage ICS, respectively. Risk of hospitalisation was greater for children with asthma prescribed one (2.58 (95% CI 1.82 to 3.66)) or two or more (3.80 (95% CI 2.41 to 5.95)) courses of oral corticosteroids in the year prior to the pandemic. DISCUSSION: People with mild and/or well-controlled asthma are neither at significantly increased risk of hospitalisation with nor more likely to die from COVID-19 than adults without asthma.

Admission blood eosinophil count, inpatient death and death at 1 year in exacerbating patients with COPD.

BACKGROUND: Blood eosinophil counts have been studied in patients with stable chronic obstructive pulmonary disease (COPD) and are a useful biomarker to guide inhaled corticosteroid use. Less is known about eosinophil counts during severe exacerbation. METHODS: In this retrospective study, 2645 patients admitted consecutively with COPD exacerbation across six UK hospitals were included in the study, and the clinical diagnosis was confirmed by a respiratory specialist. The relationship between admission eosinophil count, inpatient death and 1-year death was assessed. In a backward elimination, Poisson regression analysis using the log-link function with robust estimates, patients' markers of acute illness and stable-state characteristics were assessed in terms of their association with eosinopenia. RESULTS: 1369 of 2645 (52%) patients had eosinopenia at admission. Those with eosinopenia had a 2.5-fold increased risk of inpatient death compared with those without eosinopenia (12.1% vs 4.9%, RR=2.50, 95% CI 1.88 to 3.31, p<0.001). The same mortality risk with eosinopenia was seen among the subgroup with pneumonic exacerbation (n=788, 21.3% vs 8.5%, RR=2.5, 95% CI 1.67 to 2.24, p<0.001). In a regression analysis, eosinopenia was significantly associated with: older age and male sex; a higher pulse rate, temperature, neutrophil count, urea and C reactive protein level; a higher proportion of patients with chest X-ray consolidation and a reduced Glasgow Coma Score; and lower systolic and diastolic blood pressure measurements and lower oxygen saturation, albumin, platelet and previous admission counts. DISCUSSION: During severe COPD exacerbation, eosinopenia is common and associated with inpatient death and several markers of acute illness. Clinicians should be cautious about using eosinophil results obtained during severe exacerbation to guide treatment decisions regarding inhaled corticosteroid use.

Mortality in non-exacerbating COPD: a longitudinal analysis of UK primary care data.

INTRODUCTION: Non-exacerbating patients with chronic obstructive pulmonary disease (COPD) are a less studied phenotype. We investigated clinical characteristics, mortality rates and causes of death among non-exacerbating compared with exacerbating patients with COPD. METHODS: We used data from the Clinical Practice Research Datalink, Hospital Episode Statistics and Office for National Statistics between 1 January 2004 and 31 December 2018. Ever smokers with a COPD diagnosis with minimum 3 years of baseline information were included. We compared overall using Cox regression and cause-specific mortality rates using competing risk analysis, adjusted for age, sex, deprivation, smoking status, body mass index, GOLD stage and comorbidities. Causes of death were identified using International Classification of Diseases-10 codes. RESULTS: Among 67 516 patients, 17.3% did not exacerbate during the 3-year baseline period. Mean follow-up was 4 years. Non-exacerbators were more likely to be male (63.3% vs 52.4%, p<0.001) and less often had a history of asthma (33.9% vs 43.6%, p<0.001) or FEV1<50% predicted (23.7 vs 31.8%) compared with exacerbators. Adjusted HR for overall mortality in non-exacerbators compared with exacerbators was 0.62 (95% CI 0.56 to 0.70) in the first year of follow-up and 0.87 (95% CI 0.83 to 0.91) thereafter. Non-exacerbating patients with COPD died less of respiratory causes than exacerbators (29.2% vs 40.3%) and more of malignancies (29.4% vs 23.4%) and cardiovascular diseases (26.2% vs 22.9%). HRs for malignant and circulatory causes of death were increased after the first year of follow-up. DISCUSSION: In this primary care cohort, non-exacerbators showed distinct clinical characteristics and lower mortality rates. Non-exacerbators were equally likely to die of respiratory, malignant or cardiovascular diseases.

Frequency and severity of respiratory infections prior to COPD diagnosis and risk of subsequent postdiagnosis COPD exacerbations and mortality: EXACOS-UK health care data study.

OBJECTIVE: Little is known about how lower respiratory tract infections (LRTIs) before chronic obstructive pulmonary disease (COPD) are associated with future exacerbations and mortality. We investigated this association in patients with COPD in England. METHODS: Clinical Practice Research Datalink Aurum, Hospital Episode Statistics and Office of National Statistics data were used. Start of follow-up was patient's first ever COPD diagnosis date and a 1-year baseline period prior to start of follow-up was used to find mild LRTIs (general practice (GP) events/no antibiotics), moderate LRTIs (GP events+antibiotics) and severe LRTIs (hospitalised). Patients were categorised as having: none, 1 mild only, 2+ mild only, 1 moderate, 2+ moderate and 1+ severe. Negative binomial regression modelled the association between baseline LRTIs and subsequent COPD exacerbations and Cox proportional hazard regression was used to investigate mortality. RESULTS: In 215 234 patients with COPD, increasing frequency and severity of mild and moderate LRTIs were associated with increased rates of subsequent exacerbations compared with no recorded LRTIs (1 mild adjusted IRR 1.16, 95% CI 1.14 to 1.18, 2+ mild IRR 1.51, 95% CI 1.46 to 1.55, 1 moderate IRR 1.81, 95% CI 1.78 to 1.85, 2+ moderate IRR 2.55, 95% CI 2.48 to 2.63). Patients with 1+ severe LRTI (vs no baseline LRTIs) also showed an increased rate of future exacerbations (adjusted IRR 1.75, 95% CI, 1.70 to 1.80). This pattern of association was similar for risk of all-cause and COPD-related mortality; however, patients with 1+ severe LRTIs had the highest risk of all-cause and COPD mortality. CONCLUSION: Increasing frequency and severity of LRTIs prior to COPD diagnosis were associated with increasing rates of subsequent exacerbations, and increasing risk of all-cause and COPD-related mortality.

Recent trends in asthma diagnosis, preschool wheeze diagnosis and asthma exacerbations in English children and adolescents: a SABINA Jr study.

BACKGROUND: Asthma-related burden remains poorly characterised in children in the UK. We quantified recent trends in asthma prevalence and burden in a UK population-based cohort (1‒17-year-olds). METHODS: The Clinical Practice Research Datalink Aurum database (2008‒2018) was used to assess annual asthma incidence and prevalence in 1‒17-year-olds and preschool wheeze in 1‒5-year-olds, stratified by sex and age. During the same period, annual asthma exacerbation rates were assessed in those with either a diagnosis of preschool wheeze or asthma. RESULTS: Annual asthma incidence rates decreased by 51% from 1403.4 (95% CI 1383.7 to 1423.2) in 2008 to 688.0 (95% CI 676.3 to 699.9) per 105 person-years (PYs) in 2018, with the most pronounced decrease observed in 1‒5-year olds (decreasing by 65%, from 2556.9 (95% CI 2509.8 to 2604.7) to 892.3 (95% CI 866.9 to 918.3) per 105 PYs). The corresponding decreases for the 6‒11- and 12‒17-year-olds were 36% (1139.9 (95% CI 1110.6 to 1169.7) to 739.9 (95% CI 720.5 to 759.8)) and 20% (572.3 (95% CI 550.4 to 594.9) to 459.5 (95% CI 442.9 to 476.4)) per 105 PYs, respectively. The incidence of preschool wheeze decreased over time and was slightly more pronounced in the 1‒3 year-olds than in the 4-year-olds. Prevalence of asthma and preschool wheeze also decreased over time, from 18.0% overall in 2008 to 10.2% in 2018 for asthma. Exacerbation rates increased over time from 1.33 (95% CI 1.31 to 1.35) per 10 PYs in 2008 to 1.81 (95% CI 1.78 to 1.83) per 10 PYs in 2018. CONCLUSION: Paediatric asthma incidence decreased in the UK since 2008, particularly in 1-5-year-olds; this was accompanied by a decline in asthma prevalence. Preschool wheeze incidence also decreased in this age group. However, exacerbation rates have been increasing.

QRISK3 underestimates the risk of cardiovascular events in patients with COPD.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of cardiovascular disease (CVD). The extent to which the excess CVD risk is captured by risk factors in QRISK, a widely used CVD risk scoring tool, is not well studied. METHODS: We created an incidence cohort of diagnosed COPD patients from the United Kingdom (UK) Clinical Practice Research Datalink GOLD database (January 1998-July 2018). The outcome was a composite of fatal or non-fatal CVD events. Sex-specific age-standardised incidence ratios (SIR) were compared with values for the UK primary-care population. The observed 10-year CVD risk was derived using the Kaplan-Meier estimator and was compared with predicted 10-year risk from the QRISK3 tool. RESULTS: 13 208 patients (mean age 64.9 years, 45% women) were included. CVD incidence was 3.53 events per 100 person-years. The SIR of CVD was 1.71 (95% CI 1.61 to 1.75) in women and 1.62 (95%CI 1.54-1.64) in men. SIR was particularly high among patients younger than 65 years (women=2.13 (95% CI 1.94 to 2.19); men=1.86 (95% CI 1.74 to 1.90)). On average, the observed 10-year risk was 52% higher than QRISK predicted score (33.5% vs 22.1%). The difference was higher in patients younger than 65 years (observed risk 82% higher than predicted). CONCLUSION: People living with COPD are at a significantly heightened risk of CVD over and beyond their predicted risk. This is particularly the case for younger people whose 10-year CVD risk can be >80% higher than predicted. Risk scoring tools must be validated and revised to provide accurate CVD predictions in patients with COPD.

Asthma symptoms, spirometry and air pollution exposure in schoolchildren in an informal settlement and an affluent area of Nairobi, Kenya.

BACKGROUND: Although 1 billion people live in informal (slum) settlements, the consequences for respiratory health of living in these settlements remain largely unknown. This study investigated whether children living in an informal settlement in Nairobi, Kenya are at increased risk of asthma symptoms. METHODS: Children attending schools in Mukuru (an informal settlement in Nairobi) and a more affluent area (Buruburu) were compared. Questionnaires quantified respiratory symptoms and environmental exposures; spirometry was performed; personal exposure to particulate matter (PM2.5) was estimated. RESULTS: 2373 children participated, 1277 in Mukuru (median age, IQR 11, 9-13 years, 53% girls), and 1096 in Buruburu (10, 8-12 years, 52% girls). Mukuru schoolchildren were from less affluent homes, had greater exposure to pollution sources and PM2.5. When compared with Buruburu schoolchildren, Mukuru schoolchildren had a greater prevalence of symptoms, 'current wheeze' (9.5% vs 6.4%, p=0.007) and 'trouble breathing' (16.3% vs 12.6%, p=0.01), and these symptoms were more severe and problematic. Diagnosed asthma was more common in Buruburu (2.8% vs 1.2%, p=0.004). Spirometry did not differ between Mukuru and Buruburu. Regardless of community, significant adverse associations were observed with self-reported exposure to 'vapours, dusts, gases, fumes', mosquito coil burning, adult smoker(s) in the home, refuse burning near homes and residential proximity to roads. CONCLUSION: Children living in informal settlements are more likely to develop wheezing symptoms consistent with asthma that are more severe but less likely to be diagnosed as asthma. Self-reported but not objectively measured air pollution exposure was associated with increased risk of asthma symptoms.

Collaboration between explainable artificial intelligence and pulmonologists improves the accuracy of pulmonary function test interpretation.

BACKGROUND: Few studies have investigated the collaborative potential between artificial intelligence (AI) and pulmonologists for diagnosing pulmonary disease. We hypothesised that the collaboration between a pulmonologist and AI with explanations (explainable AI (XAI)) is superior in diagnostic interpretation of pulmonary function tests (PFTs) than the pulmonologist without support. METHODS: The study was conducted in two phases, a monocentre study (phase 1) and a multicentre intervention study (phase 2). Each phase utilised two different sets of 24 PFT reports of patients with a clinically validated gold standard diagnosis. Each PFT was interpreted without (control) and with XAI's suggestions (intervention). Pulmonologists provided a differential diagnosis consisting of a preferential diagnosis and optionally up to three additional diagnoses. The primary end-point compared accuracy of preferential and additional diagnoses between control and intervention. Secondary end-points were the number of diagnoses in differential diagnosis, diagnostic confidence and inter-rater agreement. We also analysed how XAI influenced pulmonologists' decisions. RESULTS: In phase 1 (n=16 pulmonologists), mean preferential and differential diagnostic accuracy significantly increased by 10.4% and 9.4%, respectively, between control and intervention (p<0.001). Improvements were somewhat lower but highly significant (p<0.0001) in phase 2 (5.4% and 8.7%, respectively; n=62 pulmonologists). In both phases, the number of diagnoses in the differential diagnosis did not reduce, but diagnostic confidence and inter-rater agreement significantly increased during intervention. Pulmonologists updated their decisions with XAI's feedback and consistently improved their baseline performance if AI provided correct predictions. CONCLUSION: A collaboration between a pulmonologist and XAI is better at interpreting PFTs than individual pulmonologists reading without XAI support or XAI alone.

Use of hospital services by patients with chronic conditions in sub-Saharan Africa: a systematic review and meta-analysis.

Objective: To estimate the prevalence of individual chronic conditions and multimorbidity among adults admitted to hospital in countries in sub-Saharan Africa. Methods: We systematically searched MEDLINE®, Embase®, Global Index Medicus, Global Health and SciELO for publications reporting on patient cohorts recruited between 1 January 2010 and 12 May 2023. We included articles reporting prevalence of pre-specified chronic diseases within unselected acute care services (emergency departments or medical inpatient settings). No language restrictions were applied. We generated prevalence estimates using random-effects meta-analysis alongside 95% confidence intervals, 95% prediction intervals and I2 statistics for heterogeneity. To explore associations with age, sex, country-level income status, geographical region and risk of bias, we conducted pre-specified meta-regression, sub-group and sensitivity analyses. Findings: Of 6976 identified studies, 61 met the inclusion criteria, comprising data from 20 countries and 376 676 people. None directly reported multimorbidity, but instead reported prevalence for individual conditions. Among medical admissions, the highest prevalence was human immunodeficiency virus infection (36.4%; 95% CI: 31.3-41.8); hypertension (24.4%; 95% CI: 16.7-34.2); diabetes (11.9%; 95% CI: 9.9-14.3); heart failure (8.2%; 95% CI: 5.6-11.9); chronic kidney disease (7.7%; 95% CI: 3.9-14.7); and stroke (6.8%; 95% CI: 4.7-9.6). Conclusion: Among patients seeking hospital care in sub-Saharan Africa, multimorbidity remains poorly described despite high burdens of individual chronic diseases. Prospective public health studies of multimorbidity burden are needed to generate integrated and context-specific health system interventions that act to maximize patient survival and well-being.

Validation of the recording of idiopathic pulmonary fibrosis in routinely collected electronic healthcare records in England.

BACKGROUND: Routinely-collected healthcare data provide a valuable resource for epidemiological research. Validation studies have shown that for most conditions, simple lists of clinical codes can reliably be used for case finding in primary care, however, studies exploring the robustness of this approach are lacking for diseases such as idiopathic pulmonary fibrosis (IPF) which are largely managed in secondary care. METHOD: Using the UK's Clinical Practice Research Datalink (CPRD) Aurum dataset, which comprises patient-level primary care records linked to national hospital admissions and cause-of-death data, we compared the positive predictive value (PPV) of eight diagnostic algorithms. Algorithms were developed based on the literature and IPF diagnostic guidelines using combinations of clinical codes in primary and secondary care (SNOMED-CT or ICD-10) with/without additional information. The positive predictive value (PPV) was estimated for each algorithm using the death record as the gold standard. Utilization of the reviewed codes across the study period was observed to evaluate any change in coding practices over time. RESULT: A total of 17,559 individuals had a least one record indicative of IPF in one or more of our three linked datasets between 2008 and 2018. The PPV of case-finding algorithms based on clinical codes alone ranged from 64.4% (95%CI:63.3-65.3) for a "broad" codeset to 74.9% (95%CI:72.8-76.9) for a "narrow" codeset comprising highly-specific codes. Adding confirmatory evidence, such as a CT scan, increased the PPV of our narrow code-based algorithm to 79.2% (95%CI:76.4-81.8) but reduced the sensitivity to under 10%. Adding evidence of hospitalisation to the standalone code-based algorithms also improved PPV, (PPV = 78.4 vs. 64.4%; sensitivity = 53.5% vs. 38.1%). IPF coding practices changed over time, with the increased use of specific IPF codes. CONCLUSION: High diagnostic validity was achieved by using a restricted set of IPF codes. While adding confirmatory evidence increased diagnostic accuracy, the benefits of this approach need to be weighed against the inevitable loss of sample size and convenience. We would recommend use of an algorithm based on a broader IPF code set coupled with evidence of hospitalisation.

Investigating the impact of London's ultra low emission zone on children's health: children's health in London and Luton (CHILL) protocol for a prospective parallel cohort study.

BACKGROUND: Air pollution harms health across the life course. Children are at particular risk of adverse effects during development, which may impact on health in later life. Interventions that improve air quality are urgently needed both to improve public health now, and prevent longer-term increased vulnerability to chronic disease. Low Emission Zones are a public health policy intervention aimed at reducing traffic-derived contributions to urban air pollution, but evidence that they deliver health benefits is lacking. We describe a natural experiment study (CHILL: Children's Health in London and Luton) to evaluate the impacts of the introduction of London's Ultra Low Emission Zone (ULEZ) on children's health. METHODS: CHILL is a prospective two-arm parallel longitudinal cohort study recruiting children at age 6-9 years from primary schools in Central London (the focus of the first phase of the ULEZ) and Luton (a comparator site), with the primary outcome being the impact of changes in annual air pollutant exposures (nitrogen oxides [NOx], nitrogen dioxide [NO2], particulate matter with a diameter of less than 2.5micrograms [PM2.5], and less than 10 micrograms [PM10]) across the two sites on lung function growth, measured as post-bronchodilator forced expiratory volume in one second (FEV1) over five years. Secondary outcomes include physical activity, cognitive development, mental health, quality of life, health inequalities, and a range of respiratory and health economic data. DISCUSSION: CHILL's prospective parallel cohort design will enable robust conclusions to be drawn on the effectiveness of the ULEZ at improving air quality and delivering improvements in children's respiratory health. With increasing proportions of the world's population now living in large urban areas exceeding World Health Organisation air pollution limit guidelines, our study findings will have important implications for the design and implementation of Low Emission and Clean Air Zones in the UK, and worldwide. CLINICALTRIALS: GOV: NCT04695093 (05/01/2021).