Overdiagnosis of COPD in Subjects With Unobstructed Spirometry: A BOLD Analysis

Using Machine Learning with Impulse Oscillometry Data to Develop a Predictive Model for Chronic Obstructive Pulmonary Disease and Asthma

We aimed to develop and validate a machine learning model using impulse oscillometry system (IOS) profiles for accurately classifying patients into three assessment-based categories: no airflow obstruction, asthma, and chronic obstructive pulmonary disease (COPD). Our research questions were as follows: (1) Can machine learning methods accurately classify obstructive disease states based solely on multidimensional IOS data? (2) Which IOS parameters and modeling algorithms provide the best discrimination? We used data for 480 patients (240 with COPD and 240 with asthma) and 84 healthy individuals for training. Physiological and IOS parameters were combined into six feature combinations. The classification algorithms tested were logistic regression, random forest, neural network, k-nearest neighbor, and support vector machine. The optimal feature combination for identifying individuals without pulmonary obstruction, with asthma, or with COPD included 15 IOS and physiological features. The neural network classifier achieved the highest accuracy (0.786). For discriminating between healthy and unhealthy individuals, two combinations of twenty-three features performed best in the neural network algorithm (accuracy of 0.929). When distinguishing COPD from asthma, the best combination included 15 features and the neural network algorithm achieved an accuracy of 0.854. This study provides compelling technical evidence and clinical justifications for advancing IOS data-driven models to aid in COPD and asthma management.

Exploring the causes of COPD misdiagnosis in primary care: A mixed methods study

BACKGROUND

Within primary care there exists a cohort of patients misdiagnosed with Chronic Obstructive Pulmonary Disease (COPD). Misdiagnosis can have a detrimental impact on healthcare finances and patient health and so understanding the factors leading to misdiagnosis is crucial in order to reduce misdiagnosis in the future. The objective of this study is to understand and explore the perceived causes of COPD misdiagnosis in primary care.

METHODS

A sequential mixed methods study, quantifying prevalence and features of patients misdiagnosed with COPD in primary care followed by a qualitative analysis to explore perceived causes of misdiagnosis. Quantitative data was collected for 206 patients identified as misdiagnosed with COPD within the INTEGR COPD study (NCT03482700). Qualitative data collected from 21 healthcare professionals involved in providing COPD care and 8 misdiagnosed patients who were recruited using a maximum variation purposive sampling.

RESULTS

Misinterpretation of spirometry results was the prevailing factor leading to patients initially being misdiagnosed with COPD, affecting 59% of misdiagnosed patients in this cohort. Of the 99 patients who were investigated for their underlying diagnosis; 41% had normal spirometry and 40% had asthma. Further investigation through qualitative methodology uncovered reluctance to challenge historical misdiagnoses and challenges in differential diagnosis as the underlying explanations for COPD misdiagnosis in this cohort.

CONCLUSIONS

Patients historically diagnosed with COPD without spirometric evidence are at risk of remaining labelled and treated for COPD despite non-obstructive respiratory physiology, leading to a persistent cohort of patients misdiagnosed with COPD in primary care. The lack of spirometry services during and after the COVID19 pandemic in primary care risks adding to the cohort of misdiagnosed patients. Support from respiratory specialists can potentially help to reduce the prevalence of COPD misdiagnosis in primary care.

TRIAL REGISTRATION

NCT03482700.

Evidence for overdiagnosis in noncancer conditions was assessed: a metaepidemiological study using the 'Fair Umpire' framework

OBJECTIVES

To evaluate the strength of the evidence for, and the extent of, overdiagnosis in noncancer conditions.

STUDY DESIGN AND SETTING

We systematically searched for studies investigating overdiagnosis in noncancer conditions. Using the 'Fair Umpire' framework to assess the evidence that cases diagnosed by one diagnostic strategy but not by another may be overdiagnosed, two reviewers independently identified whether a Fair Umpire-a disease-specific clinical outcome, a test result or risk factor that can determine whether an additional case does or does not have disease-was present. Disease-specific clinical outcomes provide the strongest evidence for overdiagnosis, follow-up or concurrent tests provide weaker evidence, and risk factors provide only weak evidence. Studies without a Fair Umpire provide the weakest evidence of overdiagnosis.

RESULTS

Of 132 studies, 47 (36%) did not include a Fair Umpire to adjudicate additional diagnoses. When present, the most common Umpire was a single test or risk factor (32% of studies), with disease-specific clinical outcome Umpires used in only 21% of studies. Estimates of overdiagnosis included 43-45% of screen-detected acute abdominal aneurysms, 54% of cases of acute kidney injury, and 77% of cases of oligohydramnios in pregnancy.

CONCLUSION

Much of the current evidence for overdiagnosis in noncancer conditions is weak. Application of the framework can guide development of robust studies to detect and estimate overdiagnosis in noncancer conditions, ultimately informing evidence-based policies to reduce it.

All-cause and cause-specific mortality by spirometric pattern and sex - a population-based cohort study

BACKGROUND

Chronic airway obstruction (CAO) and restrictive spirometry pattern (RSP) are associated with mortality, but sex-specific patterns of all-cause and specific causes of death have hardly been evaluated.

OBJECTIVES

To study the possible sex-dependent differences of all-cause mortality and patterns of cause-specific mortality among men and women with CAO and RSP, respectively, to that of normal lung function (NLF).

DESIGN

Population-based prospective cohort study.

METHODS

Individuals with CAO [FEV1/vital capacity (VC) < 0.70], RSP [FEV1/VC ⩾ 0.70 and forced vital capacity (FVC) < 80% predicted] and NLF (FEV1/VC ⩾ 0.70 and FVC ⩾ 80% predicted) were identified within the Obstructive Lung Disease in Northern Sweden (OLIN) studies in 2002-2004. Mortality data were collected through April 2016, totally covering 19,000 patient-years. Cox regression and Fine-Gray regression accounting for competing risks were utilized to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for age, body mass index, sex, smoking habits and pack-years.

RESULTS

The adjusted hazard for all-cause mortality was higher in CAO and RSP than in NLF (HR, 95% CI; 1.69, 1.31-2.02 and 1.24, 1.06-1.71), and the higher hazards were driven by males. CAO had a higher hazard of respiratory and cardiovascular death than NLF (2.68, 1.05-6.82 and 1.40, 1.04-1.90). The hazard of respiratory death was significant in women (3.41, 1.05-11.07) while the hazard of cardiovascular death was significant in men (1.49, 1.01-2.22). In RSP, the higher hazard for respiratory death remained after adjustment (2.68, 1.05-6.82) but not for cardiovascular death (1.11, 0.74-1.66), with a similar pattern in both sexes.

CONCLUSION

The higher hazard for all-cause mortality in CAO and RSP than in NLF was male driven. CAO was associated with respiratory death in women and cardiovascular death in men, while RSP is associated with respiratory death, similarly in both sexes.

Chronic Obstructive Pulmonary Disease Overdiagnosis and Overtreatment: A Meta-Analysis

This meta-analysis of observational studies aimed at estimating the overall prevalence of overdiagnosis and overtreatment in subjects with a clinical diagnosis of Chronic Obstructive Pulmonary Disease (COPD). MedLine, Scopus, Embase and Cochrane databases were searched, and random-effect meta-analyses of proportions were stratified by spirometry criteria (Global Initiative for COPD (GOLD) or Lower Limit of Normal (LLN)), and setting (hospital or primary care). Forty-two studies were included. Combining the data from 39 datasets, including a total of 23,765 subjects, the pooled prevalence of COPD overdiagnosis, according to the GOLD definition, was 42.0% (95% Confidence Interval (CI): 37.3-46.8%). The pooled prevalence according to the LLN definition was 48.2% (40.6-55.9%). The overdiagnosis rate was higher in primary care than in hospital settings. Fourteen studies, including a total of 8183 individuals, were included in the meta-analysis estimating the prevalence of COPD overtreatment. The pooled rates of overtreatment according to GOLD and LLN definitions were 57.1% (40.9-72.6%) and 36.3% (17.8-57.2%), respectively. When spirometry is not used, a large proportion of patients are erroneously diagnosed with COPD. Approximately half of them are also incorrectly treated, with potential adverse effects and a massive inefficiency of resources allocation. Strategies to increase the compliance to current guidelines on COPD diagnosis are urgently needed.

Underdiagnosis and misclassification of COPD in Sweden - A Nordic Epilung study

INTRODUCTION

The prevalence of COPD tends to level off in populations with decreasing prevalence of smoking but the extent of underdiagnosis in such populations needs further investigation.

AIM

To investigate underdiagnosis and misclassification of COPD with a focus on socio-economy, lifestyle determinants and healthcare utilization.

METHOD

The 1839 participants were selected from two ongoing large-scale epidemiological research programs: The Obstructive Lung Disease in Northern Sweden Studies and the West Sweden Asthma Study. COPDGOLD was defined according to the fixed post-bronchodilator spirometric criteria FEV1/FVC<0.70 in combination with respiratory symptoms.

RESULTS

Among the 128 participants who fulfilled the criteria for COPDGOLD, the underdiagnosis was 83.6% (n = 107) of which 57.9% were men. The undiagnosed participants were younger, had higher FEV1% of predicted and less frequently a family history of bronchitis. One in four of the undiagnosed had utilized healthcare and had more frequently utilized healthcare due to a burden of respiratory symptoms than the general population without COPD. Underdiagnosis was not related to educational level. Misclassification of COPD was characterized by being a woman with low education, ever smoker, having respiratory symptoms and having a previous asthma diagnosis.

CONCLUSION

In the high income country Sweden, the underdiagnosis of COPD was highly prevalent. Reduced underdiagnosis can contribute to risk factor modification, medical treatment and self-management strategies in early stages of the disease, which may prevent disease progression and improve the quality of life among those affected. Therefore, there is a need to increase the use of spirometry in primary care to improve the diagnostic accuracy.

[The FEV1/VC ratio to define bronchial obstruction: Should we use a fixed ratio or the lower limit of normal?]

INTRODUCTION

While the screening of chronic obstructive lung diseases (COPD, asthma, etc.) constitutes a major public health issue in France and worldwide, simple spirometry appears currently as the key to meeting the challenge. Since description of the forced expiratory maneuver by Robert Tiffeneau in 1947, it has been admitted that the FEV1/VC ratio permits diagnosis obstructive pulmonary diseases. However, the diagnostic criteria for this ratio remain uncertain. The long-lasting debate between advocates of a 0.7 "fixed ratio" (FR) of 0.7 and advocates of the "lower limit of normal" (LLN) remains relevant.

STATE OF THE ARTS

In this general review, we describe the respective advantages of the FR and LLN criteria according to the most recently published studies, and characterize the conditions associated with discrepancies between these criteria.

PERSPECTIVES AND CONCLUSIONS

FR and LLN appear not to share similar diagnosis values and the use of both criteria facilitates proposal of an up-to-date interpretation and diagnosis strategy in the context of first-line spirometry, particularly for patients with FEV1/VC ratio in the "grey zone".

Measuring spirometry in a lung cancer screening cohort highlights possible underdiagnosis and misdiagnosis of COPD

Introduction

COPD is underdiagnosed, and measurement of spirometry alongside low-dose computed tomography (LDCT) screening for lung cancer is one strategy to increase earlier diagnosis of this disease.

Methods

Ever-smokers at high risk of lung cancer were invited to the Yorkshire Lung Screening Trial for a lung health check (LHC) comprising LDCT screening, pre-bronchodilator spirometry and a smoking cessation service. In this cross-sectional study we present data on participant demographics, respiratory symptoms, lung function, emphysema on imaging and both self-reported and primary care diagnoses of COPD. Multivariable logistic regression analysis identified factors associated with possible underdiagnosis and misdiagnosis of COPD in this population, with airflow obstruction defined as forced expiratory volume in 1 s/forced vital capacity ratio <0.70.

Results

Out of 3920 LHC attendees undergoing spirometry, 17% had undiagnosed airflow obstruction with respiratory symptoms, representing potentially undiagnosed COPD. Compared to those with a primary care COPD code, this population had milder symptoms, better lung function and were more likely to be current smokers (p≤0.001 for all comparisons). Out of 836 attendees with a primary care COPD code who underwent spirometry, 19% did not have airflow obstruction, potentially representing misdiagnosed COPD, although symptom burden was high.

Discussion

Spirometry offered alongside LDCT screening can potentially identify cases of undiagnosed and misdiagnosed COPD. Future research should assess the downstream impact of these findings to determine whether any meaningful changes to treatment and outcomes occur, and to assess the impact on co-delivering spirometry on other parameters of LDCT screening performance such as participation and adherence. Additionally, work is needed to better understand the aetiology of respiratory symptoms in those with misdiagnosed COPD, to ensure that this highly symptomatic group receive evidence-based interventions.

Diagnostic spirometry in COPD is increasing, a comparison of two Swedish cohorts

Spirometry should be used to confirm a diagnosis of chronic obstructive pulmonary disease (COPD). This test is not always performed, leading to possible misdiagnosis. We investigated whether the proportion of patients with diagnostic spirometry has increased over time as well as factors associated with omitted or incorrectly interpreted spirometry. Data from medical reviews and a questionnaire from primary and secondary care patients with a doctors' diagnosis of COPD between 2004 and 2010 were collected. Data were compared with a COPD cohort diagnosed between 2000 and 2003. Among 703 patients with a first diagnosis of COPD between 2004 and 2010, 88% had a diagnostic spirometry, compared with 59% (p < 0.001) in the previous cohort. Factors associated with not having diagnostic spirometry were current smoking (OR 2.21; 95% CI 1.36-3.60), low educational level (OR 1.81; 1.09-3.02) and management in primary care (OR 2.28; 1.02-5.14). The correct interpretation of spirometry results increased (75% vs 82%; p = 0.010). Among patients with a repeated spirometry, 94% had a persistent FEV₁/FVC or FEV₁/VC ratio <0.70.

Identifying airway obstruction in primary care: is there a role for physiotherapists?

Aims

To examine the implementation of a physiotherapist-driven spirometry case finding service in primary care to identify new cases of COPD and confirm diagnosis of existing cases of COPD.

Methods

Four general practices were recruited. ‘At risk’ participants (aged ≥ 40 years, current/ex-smoker) and people with ‘existing’ COPD were identified from practice databases and invited to attend an assessment with a cardiorespiratory physiotherapist in each general practice. The physiotherapist performed pre/post-bronchodilator spirometry to identify or confirm a diagnosis of COPD (FEV1/FVC < 0.7). Outcome measures included number (%) of new cases of COPD, number (%) confirmed diagnosis of COPD and number (%) of high quality spirometry assessments with accurate interpretation.

Results

One hundred forty eight participants (mean age 70 years (SD 11.1), 57% female) attended a baseline assessment (117 ‘at risk’, 31’existing’ COPD) from 748 people invited. Physiotherapists performed 145 pre/post bronchodilator spirometry assessments. Obstruction on post-bronchodilator spirometry was confirmed in 17% (19/114) of ‘at risk’ and 77% (24/31) of ‘existing’ COPD. Majority of cases were classified as GOLD Stage II (63%, n = 27). Quality of pre/post bronchodilator spirometries for FEV1 were classified as A (68%), B (19%) and C (5%).

Conclusion

Physiotherapists integrated into primary care performed high quality spirometry testing, successfully case finding ‘at risk’ patients and identifying potential misdiagnosis of obstruction in some ‘existing’ COPD cases.

Trial registration

ANZCTR, ACTRN12619001127190. Registered 12 August 2019 – Retrospectively registered, http://www.ANZCTR.org.au/ACTRN12619001127190.aspx

A population-based cohort study on the risk of obstructive lung disease after bilateral oophorectomy

There is increasing evidence that sex hormones may impact the development of obstructive lung disease (OLD). Therefore, we studied the effect of bilateral oophorectomy (oophorectomy) on the development of OLD. Women were identified from the Mayo Clinic Cohort Study of Oophorectomy and Aging-2. Data were collected using the Rochester Epidemiology Project records-linkage system. A total of 1653 women who underwent oophorectomy and 1653 referent women of similar age were assessed for OLD using diagnostic codes and medical record abstraction. Women who underwent oophorectomy had an overall higher risk of all OLD, all chronic obstructive pulmonary disease (COPD), emphysema, and chronic bronchitis but not of all asthma, confirmed asthma, or confirmed COPD. The association with all OLD was stronger in women who were age ≤45 years at oophorectomy, never smokers, non-obese, and in women with benign indications; however, the interactions were not statistically significant. There was an increased risk of all asthma in women age ≤45 years at oophorectomy who took estrogen therapy. Never smokers of all ages had a stronger association of oophorectomy with all asthma and all COPD, whereas smokers had a stronger association of oophorectomy with emphysema and chronic bronchitis. Non-obese women of all ages had a stronger association of oophorectomy with all COPD, emphysema, and chronic bronchitis. The results of this study combined with the increased risk of several chronic diseases reported in previous studies suggest that oophorectomy in premenopausal women should be avoided unless there is clear evidence of a high genetic risk of ovarian cancer.

Long-term mortality in ischemic stroke patients with concomitant chronic obstructive pulmonary disease

BACKGROUND

Long-term mortality in ischemic stroke patients with concomitant COPD has been largely unexplored. This study aimed to compare long-term all-cause mortality in ischemic stroke patients with and without COPD.

METHODS

This was a retrospective cohort study of ischemic stroke patients with and without COPD in the Geisinger Neuroscience Ischemic Stroke database to examine all-cause mortality up to 3 years using Kaplan-Meier estimator and Cox proportional hazards model.

RESULTS

Of the 6,589 ischemic stroke patients included in this study, 5,525 (83.9%) did not have COPD (group A). Group B (n=1,006) consisted of patients with COPD diagnosis by ICD-9/10-CM codes. COPD patients in Group C (n=233) were diagnosed by spirometry, and in Group D (n=175) by both ICD-9/10-CM codes and spirometry confirmation. The survival probabilities at three years in Group B, C, and D were significantly lower than in Group A. Group B (HR=1.262, 95% CI 1.122-1.42, p<0.001) and group C (HR=1.251, 95% CI 1.01-1.55, p=0.041) had significantly lower hazard of mortality compared to group A. There was no significant difference in survival between COPD subtypes of chronic bronchitis and emphysema. Patients in Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2 stage had an increased mortality hazard compared to the GOLD 1 stage.

CONCLUSIONS

While ischemic stroke patients with preexisting COPD have worse long-term survival than those without COPD, the results largely depended on the definition of COPD used. These results suggest that ischemic stroke patients with COPD need more personalized medical care to decrease long-term mortality.

Chronic Bronchitis Affects Outcomes in Smokers without Chronic Obstructive Pulmonary Disease (COPD)

Background. Chronic bronchitis (CB) importantly affects outcomes in smokers with COPD, but the effects on smokers without COPD are less well known and less emphasized. The aim of our study was to investigate the possible effects of CB on clinical outcomes in smokers without COPD (noCOPD) and compare them with the effects in smokers with COPD (COPD). Methods. For that purpose, we studied 511 smokers, 302 with and 209 without COPD, followed for 10 years in an academic COPD ambulatory setting. Chronic bronchitis was defined as the presence of cough and sputum production for at least 3 months in each of two consecutive years. All subjects underwent clinical and functional examination with spirometry, diffusion capacity (DLco), 6-min walking test (6MWT), mMRC Dyspnoea Scale, COPD Assessment Test (CAT), and recording of annual frequency of exacerbations. All-cause mortality during follow-up was recorded. Results. 27% of noCOPD and 45% of COPD had CB. noCOPD with CB had lower FEV₁ and DLco, worse 6MWT, more dyspnoea, a higher number of exacerbations and lower survival than noCOPD without CB. CB did not affect FEV₁ decline in noCOPD but it significantly did in COPD. Conclusions. The presence of chronic bronchitis in smokers without COPD will significantly affect symptoms, quality of life, and survival, underlining the importance of recognizing the condition and managing it accordingly.

Erroneous data: The Achilles' heel of AI and personalized medicine

This paper reviews dilemmas and implications of erroneous data for clinical implementation of AI. It is well-known that if erroneous and biased data are used to train AI, there is a risk of systematic error. However, even perfectly trained AI applications can produce faulty outputs if fed with erroneous inputs. To counter such problems, we suggest 3 steps: (1) AI should focus on data of the highest quality, in essence paraclinical data and digital images, (2) patients should be granted simple access to the input data that feed the AI, and granted a right to request changes to erroneous data, and (3) automated high-throughput methods for error-correction should be implemented in domains with faulty data when possible. Also, we conclude that erroneous data is a reality even for highly reputable Danish data sources, and thus, legal framework for the correction of errors is universally needed.

A novel methodological framework was described for detecting and quantifying overdiagnosis

OBJECTIVES

Methods to quantify overdiagnosis of screen detected cancer have been developed, but methods for quantifying overdiagnosis of non-cancer conditions (whether symptomatic or asymptomatic) have been lacking. We aimed to develop a methodological framework for quantifying overdiagnosis that may be used for asymptomatic or symptomatic conditions, and used Gestational Diabetes Mellitus as an example of how it may be applied.

STUDY DESIGN AND SETTING

We identify two earlier definitions for overdiagnosis, a narrower prognosis-based definition, and a wider utility-based definition. Building on the central importance of the concepts of prognostic information and clinical utility of a diagnosis, we consider the following questions: within a target population, do people found to have a disease using one diagnostic strategy but found not to have the disease using another diagnostic strategy (so called 'additional diagnoses'), have an increased risk of adverse clinical outcomes without treatment (prognosis evidence), and/or a decreased risk of adverse outcomes with treatment (utility evidence)?

RESULTS

Using Causal Directed Acyclic Graphs and Fair Umpires, we illuminate the relationships between diagnostics strategies and the frequency of overdiagnosis. We then use the example of Gestational Diabetes Mellitus to demonstrate how the Fair Umpire framework may be applied to estimate overdiagnosis.

CONCLUSION

Our framework may be used to quantify overdiagnosis in non-cancer conditions (and in cancer conditions), as well as to guide further studies on this topic.

Effect of doxofylline on pulmonary inflammatory response and oxidative stress during mechanical ventilation in rats with COPD

OBJECTIVE

To evaluate the effects of doxofylline on inflammatory responses and oxidative stress during mechanical ventilation in rats with chronic obstructive pulmonary disease (COPD).

METHODS

Eight-week-old male Sprague Dawley rats were selected, and the COPD rat model was constructed. The rats were randomly divided into a model group (group M), a model + normal saline group (group N), a doxofylline group (group D), and a control group fed with conventional chow and given normal oxygen supply (group C) (n = 12 in each group). Tracheal intubation and mechanical ventilation were conducted in the rats in each group after anesthesia. A real-time intravenous infusion with 50 mg/kg of doxofylline was conducted in group D, and there was no drug intervention in groups C, N and M. Pathological manifestations of the pulmonary tissues were observed and compared among the groups. And some indicators were evaluated.

RESULTS

(1) The pulmonary tissues of the rats in groups M, N, and D exhibited typical pathological histological changes of COPD. (2) Groups M, N, and D showed increased Ppeak, PaCO2, total white blood cell count in BALF, and IL-8, TNF-α, and MDA levels in the pulmonary tissue and BALF, and decreased PaO2 and IL-10 and SOD levels, compared with group C. (3). Group D showed decreased Ppeak, PaCO2, total white blood cell count in BALF, and IL-8, TNF-α, and MDA levels in the pulmonary tissue, and increased PaO2 and IL-10 and SOD levels, compared with group N or M.

CONCLUSION

Doxofylline was shown to improve ventilation and air exchange during mechanical ventilation in rats with COPD, reduce the inflammatory response and oxidative stress, and mitigate the degree of pulmonary tissue injury.

The Impact of an Electronic Health Record Intervention on Spirometry Completion in Patients with Chronic Obstructive Pulmonary Disease

Spirometry is necessary to diagnose chronic obstructive pulmonary disease (COPD), yet a large proportion of patients are diagnosed and treated without having received testing. This study explored whether the effects of interventions using the electronic health record (EHR) to target patients diagnosed with COPD without confirmatory spirometry impacted the incidence rates of spirometry referrals and completions. This retrospective before and after study assessed the impact of provider-facing clinical decision support that identified patients who had a diagnosis of COPD but had not received spirometry. Spirometry referrals, completions, and results were ascertained 1.5 years prior to and 1.5 years after the interventions were initiated. Inhaler prescriptions by class were also tallied. There were 10,949 unique patients with a diagnosis of COPD who were eligible for inclusion. 4,895 patients (44.7%) were excluded because they had completed spirometry prior to the cohort start dates. The pre-intervention cohort consisted of 2,622 patients, while the post-intervention cohort had 3,392. Spirometry referral rates pre-intervention were 20.2% compared to 31.6% post-intervention (p < 0.001). Spirometry completion rates rose from 13.2% pre-intervention to 19.3% afterwards (p < 0.001). 61.7% (585 of 948) had no evidence of airflow obstruction. After excluding patients with a diagnosis of asthma, 25.8% (126 of 488) patients who had no evidence of airflow obstruction had prescriptions for long-acting bronchodilators or inhaled steroids. A concerted EHR intervention modestly increased spirometry referral and completion rates in patients with a diagnosis of COPD without prior spirometry and decreased misclassification of disease.

Missed diagnosis or misdiagnosis: How often do hospitalised patients with a diagnosis of chronic obstructive pulmonary disease (COPD) have spirometry that supports the diagnosis?

BACKGROUND

Chronic obstructive pulmonary disease is one of the most common clinical diagnoses among hospital inpatients. Diagnosis requires the demonstration of post-bronchodilator airflow obstruction. However, it is uncertain how often spirometry results are available at the time a diagnostic label of COPD is applied.

AIM

To identify how frequently spirometry results were available following an inpatient admission with a clinical diagnosis of COPD, and to determine how often the available spirometry results supported a clinical diagnosis of COPD. Inhaler prescription, at discharge, was also evaluated to determine one of the potential implications of diagnostic inaccuracy.

METHODS

A single centre retrospective observational study was undertaken at a 400-bed metropolitan health service between October 2016 and March 2018.

RESULTS

A total of 2239 inpatient separations occurred in 1469 individuals who had a clinical diagnosis of COPD during the study. Spirometry results were not available in 43.6% (n = 641) of those with a diagnosis of COPD. A further 19.7% (n = 289) had spirometry results available at the time of admission, that did not demonstrate fixed airflow obstruction. The available prescribing data (n = 443) demonstrated that inhaled medications were prescribed in a similar pattern, regardless of the availability of spirometry, or whether the results supported a clinical diagnosis of COPD.

CONCLUSIONS

Inpatients with a clinical diagnosis of COPD frequently did not have supportive spirometry results that confirmed the diagnosis or had results inconsistent with COPD. Misdiagnosis and inappropriate prescribing require further attention to improve the quality of care in this setting. This article is protected by copyright. All rights reserved.

A cross-sectional analysis of diagnosis and management of chronic obstructive pulmonary disease in people living with HIV: Opportunities for improvement

Chronic obstructive pulmonary disease (COPD) is common in people living with HIV (PLWH). We sought to evaluate the appropriateness of COPD diagnosis and management in PLWH, comparing results to HIV-uninfected persons.We conducted a cross-sectional analysis of Veterans enrolled in the Examinations of HIV-Associated Lung Emphysema study, in which all participants underwent spirometry at enrollment and reported respiratory symptoms on self-completed surveys. Primary outcomes were misdiagnosis and under-diagnosis of COPD, and the frequency and appropriateness of inhaler prescriptions. Misdiagnosis was defined as having an International Classification of Diseases (ICD)-9 diagnosis of COPD without spirometric airflow limitation (post-bronchodilator forced expiratory volume in 1-second [FEV1]/Forced vital capacity [FVC] < 0.7). Under-diagnosis was defined as having spirometry-defined COPD without a prior ICD-9 diagnosis.The analytic cohort included 183 PLWH and 152 HIV-uninfected participants. Of 25 PLWH with an ICD-9 diagnosis of COPD, 56% were misdiagnosed. Of 38 PLWH with spirometry-defined COPD, 71% were under-diagnosed. In PLWH under-diagnosed with COPD, 85% reported respiratory symptoms. Among PLWH with an ICD-9 COPD diagnosis as well as in those with spirometry-defined COPD, long-acting inhalers, particularly long-acting bronchodilators (both beta-agonists and muscarinic antagonists) were prescribed infrequently even in symptomatic individuals. Inhaled corticosteroids were the most frequently prescribed long-acting inhaler in PLWH (28%). Results were overall similar amongst the HIV-uninfected.COPD was frequently misdiagnosed and under-diagnosed in PLWH, similar to uninfected-veterans. Among PLWH with COPD and a likely indication for therapy, long-acting inhalers were prescribed infrequently, particularly guideline-concordant, first-line long-acting bronchodilators. Although not a first-line controller therapy for COPD, inhaled corticosteroids were prescribed more often.

Heterogeneity within and between physician-diagnosed asthma and/or COPD: NOVELTY cohort

BACKGROUND

Studies of asthma and chronic obstructive pulmonary disease (COPD) typically focus on these diagnoses separately, limiting understanding of disease mechanisms and treatment options. NOVELTY is a global, 3-year, prospective observational study of patients with asthma and/or COPD from real-world clinical practice. We investigated heterogeneity and overlap by diagnosis and severity in this cohort.

METHODS

Patients with physician-assigned asthma, COPD or both (asthma+COPD) were enrolled, and stratified by diagnosis and severity. Baseline characteristics were reported descriptively by physician-assigned diagnosis and/or severity. Factors associated with physician-assessed severity were evaluated using ordinal logistic regression analysis.

RESULTS

Of 11 243 patients, 5940 (52.8%) had physician-assigned asthma, 1396 (12.4%) had asthma+COPD and 3907 (34.8%) had COPD; almost half were from primary care. Symptoms, health-related quality of life and spirometry showed substantial heterogeneity and overlap between asthma, asthma+COPD and COPD, with 23%, 62% and 64% of patients, respectively, having a ratio of post-bronchodilator forced expiratory volume in 1 s to forced vital capacity below the lower limit of normal. Symptoms and exacerbations increased with greater physician-assessed severity and were higher in asthma+COPD. However, 24.3% with mild asthma and 20.4% with mild COPD had experienced ≥1 exacerbation in the past 12 months. Medication records suggested both under-treatment and over-treatment relative to severity. Blood eosinophil counts varied little across diagnosis and severity groups, but blood neutrophil counts increased with severity across all diagnoses.

CONCLUSION

This analysis demonstrates marked heterogeneity within, and overlap between, physician-assigned diagnosis and severity groups in patients with asthma and/or COPD. Current diagnostic and severity classifications in clinical practice poorly differentiate between clinical phenotypes that may have specific risks and treatment implications.

Prevalence and characteristics of chronic obstructive pulmonary disease in China with a diagnostic criterion of FEV1/FVC less than the lower limit of normal-a reanalysis of Chinese epidemiological survey of COPD (CESCOPD) study

Background

To reappraise the prevalence and characteristics of chronic obstructive pulmonary disease (COPD) in China with a criterion of FEV₁/FVC < the lower limit of normal (LLN).

Methods

We assessed the incidence and characteristics of airflow limitation using data from the Chinese Epidemiological Survey of COPD study-a multicenter, randomized trial, with an age-dependent LLN reference equation [established by the Guangzhou Institute of Respiratory Health (GIRH)]. Questionnaire and spirometry data were collected for all eligible subjects. COPD prevalence, risk factors, severity distribution, as well as comparisons of characteristics between the LLN and 0.7 were analyzed.

Results

COPD prevalence was 9.0% among participants aged 40-80 years in China with the criterion of LLN. Greater prevalence was observed in female sex, rural areas and never smokers than with the GOLD 0.7 fixed ratio. Age distribution showed a higher incidence of COPD in people under 60 years but lower in participants over 60 years of age. With the LLN FEV₁ reference equation, patients in stage I were decreased (15.8% vs. 24.6%, P<0.001), while the proportion of patients in stage III and IV were increased when compared with the China 2002 revised equation (27.7% vs. 21.1%, for stage III, P<0.001; 8.7% vs. 5.6% for stage IV, P=0.001). Only 30.8% of patients with COPD had ever been "diagnosed" with COPD and 60.6% of the patients had respiratory symptoms, both lower than that under the GOLD 0.7 fixed-ratio criterion (35.5%, P=0.004; 64.8% for symptoms, P=0.014).

Conclusions

With the GIRH-LLN criterion, COPD prevalence was slightly higher, and a large number of women, rural patients and nonsmokers with young age and little symptoms were diagnosed when compared with GOLD 0.7 fixed ratio. These subjects may, therefore, deserve further attention and may warrant regular follow-up.

Trial Registration

Registration number: ChiCTR-ECS-13004110.

Large underreporting of COPD as cause of death-results from a population-based cohort study

BACKGROUND

In 2019, WHO estimated COPD to be the third leading cause of death in the world. However, COPD is probably underestimated as cause of death due to the well-known under-diagnosis.

AIM

To evaluate the proportion of and factors associated with COPD recorded as cause of death in a long-term follow-up of a population-based COPD cohort.

METHODS

The study population includes all individuals (n = 551) with COPD defined as chronic airway obstruction (post-bronchodilator FEV₁/FVC<0.70) + respiratory symptoms identified after re-examinations of four population-based cohorts. Mortality and underlying or contributing cause of death following ICD-10 classification were collected from the Swedish National Board of Health and Welfares register from date of examination in 2002-04 until 2016.

RESULTS

The study sample consisted of 32.3% GOLD 1, 55.9% GOLD 2, and 11.8% GOLD 3-4. The mean follow-up time was 10.3 (SD3.77) years and the cumulative mortality 45.0%. COPD (ICD-10 J43-J44) was recorded on 28.2% (n = 70) of the death certificates (11.1%, 25.7% and 57.1% by GOLD stage), whereof n = 35 had COPD recorded as underlying and n = 35 as contributing cause of death. To have COPD recorded as cause of death was independently associated with ex- and current smoking and a self-reported physician diagnosis of COPD, while male sex, overweight/obesity and higher FEV₁% of predicted associated with the absence.

CONCLUSIONS

COPD was largely underreported cause of death. Even among those with severe/very severe disease, COPD was only mentioned on 57.1% of the death certificates.

Chronic obstructive pulmonary disease exacerbation fundamentals: Diagnosis, treatment, prevention and disease impact

In chronic obstructive pulmonary disease (COPD), exacerbations (ECOPD), characterized by an acute deterioration in respiratory symptoms, are fundamental events impacting negatively upon disease progression, comorbidities, wellbeing and mortality. ECOPD also represent the largest component of the socioeconomic burden of COPD. ECOPDs are currently defined as acute worsening of respiratory symptoms that require additional therapy. Definitions that require worsening of dyspnoea and sputum volume/purulence assume that acute infections, especially respiratory viral infections, and/or exposure to pollutants are the main cause of ECOPD. But other factors may contribute to ECOPD, such as the exacerbation of other respiratory diseases and non-respiratory diseases (e.g., heart failure, thromboembolism). The complexity of worsening dyspnoea has suggested a need to improve the definition of ECOPD using objective measurements such as blood counts and C-reactive protein to improve accuracy of diagnosis and a personalized approach to management. There are three time points when we can intervene to improve outcomes: acutely, to attenuate the length and severity of an established exacerbation; in the aftermath, to prevent early recurrence and readmission, which are common, and in the long-term, establishing preventative measures that reduce the risk of future events. Acute management includes interventions such as corticosteroids or antibiotics and measures to support the respiratory system, including non-invasive ventilation (NIV). Current therapies are broad and better understanding of clinical phenotypes and biomarkers may help to establish a more tailored approach, for example in relation to antibiotic prescription. Other unmet needs include effective treatment for viruses, which commonly cause exacerbations. Preventing early recurrence and readmission to hospital is important and the benefits of interventions such as antibiotics or anti-inflammatories in this period are not established. Domiciliary NIV in those patients who are persistently hypercapnic following discharge and pulmonary rehabilitation can have a positive impact. For long-term prevention, inhaled therapy is key. Dual bronchodilators reduce exacerbation frequency but in patients with continuing exacerbations, triple therapy should be considered, especially if blood eosinophils are elevated. Other options include phosphodiesterase inhibitors and macrolide antibiotics. ECOPD are a key component of the assessment of COPD severity and future outcomes (quality of life, hospitalisations, health care resource utilization, mortality) and are a central component in pharmacological management decisions. Targeted therapies directed towards specific pathways of inflammation are being explored in exacerbation prevention, and this is a promising avenue for future research.

Artificial Intelligence/Machine Learning in Respiratory Medicine and Potential Role in Asthma and COPD Diagnosis

Artificial intelligence (AI) and machine learning, a subset of AI, are increasingly used in medicine. AI excels at performing well-defined tasks, such as image recognition; for example, classifying skin biopsy lesions, determining diabetic retinopathy severity, and detecting brain tumors. This article provides an overview of the use of AI in medicine and particularly in respiratory medicine, where it is used to evaluate lung cancer images, diagnose fibrotic lung disease, and more recently is being developed to aid the interpretation of pulmonary function tests and the diagnosis of a range of obstructive and restrictive lung diseases. The development and validation of AI algorithms requires large volumes of well-structured data, and the algorithms must work with variable levels of data quality. It is important that clinicians understand how AI can function in the context of heterogeneous conditions such as asthma and chronic obstructive pulmonary disease where diagnostic criteria overlap, how AI use fits into everyday clinical practice, and how issues of patient safety should be addressed. AI has a clear role in providing support for doctors in the clinical workplace, but its relatively recent introduction means that confidence in its use still has to be fully established. Overall, AI is expected to play a key role in aiding clinicians in the diagnosis and management of respiratory diseases in the future, and it will be exciting to see the benefits that arise for patients and doctors from its use in everyday clinical practice.

Time-ordered comorbidity correlations identify patients at risk of mis- and overdiagnosis

Diagnostic errors are common and can lead to harmful treatments. We present a data-driven, generic approach for identifying patients at risk of being mis- or overdiagnosed, here exemplified by chronic obstructive pulmonary disease (COPD). It has been estimated that 5-60% of all COPD cases are misdiagnosed. High-throughput methods are therefore needed in this domain. We have used a national patient registry, which contains hospital diagnoses for 6.9 million patients across the entire Danish population for 21 years and identified statistically significant disease trajectories for COPD patients. Using 284,154 patients diagnosed with COPD, we identified frequent disease trajectories comprising time-ordered comorbidities. Interestingly, as many as 42,459 patients did not present with these time-ordered, common comorbidities. Comparison of the individual disease history for each non-follower to the COPD trajectories, demonstrated that 9597 patients were unusual. Survival analysis showed that this group died significantly earlier than COPD patients following a trajectory. Out of the 9597 patients, we identified one subgroup comprising 2185 patients at risk of misdiagnosed COPD without the typical events of COPD patients. In all, 10% of these patients were diagnosed with lung cancer, and it seems likely that they are underdiagnosed for lung cancer as their laboratory test values and survival pattern are similar to such patients. Furthermore, only 4% had a lung function test to confirm the COPD diagnosis. Another subgroup with 2368 patients were found to be at risk of "classically" overdiagnosed COPD that survive >5.5 years after the COPD diagnosis, but without the typical complications of COPD.

COPD Comorbidity Profiles and 2-Year Trajectory of Acute and Postacute Care Use

BACKGROUND

Multiple morbidity is the norm in advanced COPD and contributes to high symptom burden and worse outcomes.

RESEARCH QUESTION

Can distinct comorbidity profiles be identified and validated in a community-based sample of patients with COPD from a large integrated health care system using a standard, commonly used diagnostic code-based comorbidity index and downstream 2-year health care use data?

STUDY DESIGN AND METHODS

In this retrospective cohort study, we used latent class analysis (LCA) to identify comorbidity profiles in a population-based sample of 91,453 patients with a COPD diagnosis between 2011 and 2015. We included specific comorbid conditions from the Charlson Comorbidity Index (CCI) and accounted for variation in underlying prevalence of different comorbidities across the three study sites. Sociodemographic, clinical, and health-care use data were obtained from electronic health records (EHRs). Multivariate logistic regression analysis was used to compare rates of acute and postacute care use by class.

RESULTS

The mean age was 71 ± 11 years, 55% of patients were women, 23% of patients were people of color, and 80% of patients were former or current smokers. LCA identified four distinct comorbidity profiles with progressively higher CCI scores: low morbidity (61%; 1.9 ± 1.4), metabolic renal (21%; 4.7 ± 1.8), cardiovascular (12%; 4.6 ± 1.9), and multimorbidity (7%; 7.5 ± 1.7). In multivariate models, during 2 years of follow-up, a significant, nonoverlapping increase was found in the odds of having any all-cause acute (hospitalizations, observation stays, and ED visits) and postacute care use across the comorbidity profiles.

INTERPRETATION

Distinct comorbidity profiles can be identified in patients with COPD using standard EHR-based diagnostic codes, and these profiles are associated with subsequent acute and postacute care use. Population-based risk stratification schemes for end-to-end, comprehensive COPD management should consider integrating comorbidity profiles such as those found in this study.

Normal Routine Spirometry Can Mask COPD/Emphysema in Symptomatic Smokers

Background

Recent studies have emphasized the difficulty of early detection of chronic obstructive pulmonary disease (COPD) in symptomatic smokers with normal routine spirometry. This includes post-bronchodilator normal forced expiratory volume in 1 second (FEV₁)(L)≥80% predicted, forced vital capacity (FVC)(L)≥80% predicted, and FEV₁/FVC ≥70% or greater than age corrected lower limit of normal (LLN). However, in COPD the pathologic site of small airway obstruction and emphysema begins in the small peripheral airways ≤2 mm id which normally contribute <20% of total airway resistance.

Methods

Expiratory airflow at high and low lung volumes post-bronchodilator were measured and correlated with lung computed tomography (CT) and lung pathology (6 patients) in 16 symptomatic, treated smokers, and all with normal routine spirometry.

Results

Despite normal routine spirometry, all16 patients had isolated, abnormal forced expiratory flow at 75% of FVC (FEF₇₅) using data from Knudson et al, Hankinson et al NHAMES III, and Quanjer et al and the Global Lung Function Initiative. This reflects isolated detection of small airways obstruction and/or emphysema. Measuring airflow at FEF₅₀ detected only 8 of 16 patients, maximal expiratory flow at 25%-75% of FVC (MEF_25-75) only 4 of 16, residual volume (RV) 4 of 16, and RV to total lung capacity ratio only 2 of 16. There was excellent correlation between limited lung pathology and lung CT for absence of emphysema.

Conclusion

This study confirms our earlier observations that detection of small airways obstruction and/or emphysema, in symptomatic smokers with normal routine spirometry, requires analysis of expiratory airflow at low lung volumes, including FEF₇₅. Dependence upon normal routine spirometry may result in clinical and physiologic delay in the diagnosis and treatment in symptomatic smokers with emphysema and small airways obstruction.

Development and Validation of a Method to Estimate COPD Severity in Multiple Datasets: A Retrospective Study

Introduction

Outcomes in chronic obstructive pulmonary disease (COPD) such as symptoms, hospitalisations and mortality rise with increasing disease severity. However, the heterogeneity of electronic medical records presents a significant challenge in measuring severity across geographies. We aimed to develop and validate a method to approximate COPD severity using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 classification scheme, which categorises patients based on forced expiratory volume in 1 s, hospitalisations and the modified Medical Research Council dyspnoea scale or COPD Assessment Test.

Methods

This analysis was part of a comprehensive retrospective study, including patients sourced from the IQVIA Medical Research Data [IMRD; incorporating data from The Health Improvement Network (THIN), a Cegedim database] and the Clinical Practice Research Datalink (CPRD) in the UK, the Disease Analyzer in Germany and the Longitudinal Patient Data in Italy, France and Australia. Patients in the CPRD with the complete set of information required to calculate GOLD 2011 groups were used to develop the method. Ordinal logistic models at COPD diagnosis and at index (first episode of triple therapy) were then used to validate the method to estimate COPD severity, and this was applied to the full study population to estimate GOLD 2011 categories.

Results

Overall, 4579 and 12,539 patients were included in the model at COPD diagnosis and at index, respectively. Models correctly classified 74.4% and 75.9% of patients into severe and non-severe categories at COPD diagnosis and at index, respectively. Age, gender, time between diagnosis and start of triple therapy, healthcare resource use, comorbid conditions and prescriptions were included as covariates.

Conclusion

This study developed and validated a method to approximate disease severity based on GOLD 2011 categories that can potentially be used in patients without all the key parameters needed for this calculation.

Spirometry in chronic obstructive pulmonary disease in Norwegian general practice

Background

General practitioners (GPs) in Norway increasingly use spirometry diagnostically as well as in follow up of patients with respiratory complaints, but little is known about their skills and knowledge in this area. The aim of the present study was to investigate how GPs interpret a case history and spirometry recordings of a patient with chronic obstructive pulmonary disease (COPD), and their knowledge about their own spirometer.

Methods

A web-based survey, consisting of a case history and spirometry recordings of a patient with COPD, was distributed to the 4700 members of the Norwegian GP Association. In addition to background information about themselves and their spirometer, topics included whether they requested, and how they interpreted, a spirometry reversibility-test, identification of the of most likely diagnosis, and recognition of the spirometry parameters used to diagnose COPD and grade airway obstruction. Immediate feedback was provided for educational purposes.

Results

Six hundred thirty GPs responded. Twenty six percent would not request a reversibility test, but 81% identified COPD as the most likely diagnosis. Less than 50% correctly identified the spirometry parameters used for diagnosis of COPD and grading the airway obstruction. One in five (21%) did not know which spirometer was used in their own practice, and 49 and 61% did not know which reference values were used for adults and children, respectively. Participants evaluated the survey as useful (average 74 points on a 0–100 scale) and would like more case-based surveys concerning use of spirometry in the future (average 91 points).

Conclusion

In this cohort of self-selected GPs, probably more interested in respiratory medicine than the average GP, we identified several problem areas and gaps in knowledge regarding the use of spirometry.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-020-01310-x.

CoughMatch - Subject Verification Using Cough for Personal Passive Health Monitoring

Automatic cough detection using audio has advanced passive health monitoring on devices such as smart phones and wearables; it enables capturing longitudinal health data by eliminating user interaction and effort. One major issue arises when coughs from surrounding people are also detected; capturing false coughs leads to significant false alarms, excessive cough frequency, and thereby misdiagnosis of user condition. To address this limitation, in this paper, a method is proposed that creates a personal cough model of the primary subject using limited number of cough samples; the model is used by the automatic cough detection to verify whether the identified coughs match the personal pattern and belong to the primary subject. A Gaussian mixture model is trained using audio features from cough to implement the subject verification method; novel cough embeddings are learned using neural networks and integrated into the model to further improve the prediction accuracy. We analyze the performance of the method using our cough dataset collected by a smart phone in a clinical study. Population in the dataset involves subjects categorized of healthy or patients with COPD or Asthma, with the purpose of covering a wider range of pulmonary conditions. Cross-subject validation on a diverse dataset shows that the method achieves an average error rate of less than 10%, using a personal cough model generated by only 5 coughs from the primary subject.

Overdiagnosis and overtreatment; how to deal with too much medicine

The past few decades have seen medical science making rapid strides in the field of diagnostic technologies, thus making it possible to detect some conditions at a very early stage. An unwanted effect of these developments is overdiagnosis which occurs when a true abnormality is discovered, but detection of that abnormality and its treatment does not benefit the patient. Overdiagnosis is encountered as a result cancer screening, in genetic diseases and in some chronic conditions when disease definition is broadened. There is urgent need of development of evidence based decision-making tools for clinicians which will help patients understand the benefits and harms of different screening and treatment methods. And the treating physician has to play a important role to convince the patient that watchful waiting, for some of the lesions may be the best option available in some circumstances.

Geographical and sociodemographic differences in discontinuation of medication for Chronic Obstructive Pulmonary Disease - A Cross-Classified Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA)

BACKGROUND

While discontinuation of COPD maintenance medication is a known problem, the proportion of patients with discontinuation and its geographical and sociodemographic distribution are so far unknown in Sweden. Therefore, we analyse this question by applying an innovative approach called multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA).

PATIENTS AND METHODS

We analysed 49,019 patients categorized into 18 sociodemographic contexts and 21 counties of residence. All patients had a hospital COPD diagnosis and had been on inhaled maintenance medication during the 5 years before the study baseline in 2010. We defined "discontinuation" as the absolute lack of retrieval from a pharmacy of any inhaled maintenance medication during 2011. We performed a cross-classified MAIHDA and obtained the average proportion of discontinuation, as well as county and sociodemographic absolute risks, and compared them with a proposed benchmark value of 10%. We calculated the variance partition coefficient (VPC) and the area under the receiver operating characteristics curve (AUC) to quantify county and sociodemographic differences. To summarize the results, we used a framework with 15 scenarios defined by the size of the differences and the level of achievement in relation to the benchmark value.

RESULTS

Around 18% of COPD patients in Sweden discontinued maintenance medication, so the benchmark value was not achieved. There were very small county differences (VPC=0.35%, AUC=0.54). The sociodemographic differences were small (VPC=4.98%, AUC=0.57).

CONCLUSION

Continuity of maintenance medication among COPD patients in Sweden could be improved by reducing the unjustifiably high prevalence of discontinuation. The very small county and small sociodemographic differences should motivate universal interventions across all counties and sociodemographic groups. Geographical analyses should be combined with sociodemographic analyses, and the cross-classified MAIHDA is an appropriate tool to assess health-care quality.

Assessment of comorbidities and prognosis in patients with COPD diagnosed with the fixed ratio and the lower limit of normal: a systematic review and meta-analysis

BACKGROUND

Currently, the diagnosis of chronic obstructive pulmonary disease (COPD) is not uniform, COPD guidelines recommend fixed ratio (FR), whereas ATS and ERS define airflow obstruction based on lower limit of normal (LLN). We aim to determine if there is difference between the two diagnostic criteria for morbidity, mortality, exacerbation.

METHODS

Four databases and all relevant studies from the references were searched from inception to June 25, 2019, to find studies that described the rate of comorbidity, the exacerbation rates, mortality in COPD patients. Data analysis was performed using STATA/SE 14.0 and followed the standard of Cochrane Collaboration. A sensitivity analysis was performed to find the source of heterogeneity.

RESULTS

Thirteen studies and 154,447 participants were finally included in this meta-analysis. The 11 cohort studies and 2 cross-sectional studies were all high-quality. Patients with airflow limitation according to either FR or LLN had higher mortality (HR_FR+/LLN- = 1.27, 95% CI = 1.14-1.42; HR_FR-/LLN+ = 1.83, 95% CI = 1.17-2.86) than those who met neither criteria. When compared with the FR-/LLN- criteria, those who met the FR criteria were more likely to exacerbate (HR _FR+/LLN- = 1.64, 95% CI = 1.09-2.46; HR _FR-/LLN+ = 1.58, 95% CI = 0.70-3.55). The meta-analysis for comorbidities showed no significant difference between patients who met neither criteria and those who met LLN or FR criteria.

CONCLUSION

The patients with airflow limitations according to FR were more likely to exacerbate than those with LLN only. Patients that met either FR or LLN were more likely to have higher mortality than FR-/LLN-. There was no difference between the FR+/LLN- and FR-/LLN+ groups for the occurrence of comorbidities.

Quality of Life and Limitations in Daily Life of Stable COPD Outpatients in a Real-World Setting in Austria - Results from the CLARA Project

Background

COPD patients suffer from respiratory symptoms and limitations in daily life. We aimed to characterize the impact of disease on overall health, daily life, and perceived well-being in COPD outpatients.

Methods

We conducted a national, cross-sectional study among pulmonologists and general practitioners (GPs). The St. George’s Respiratory Questionnaire for COPD patients (SGRQ-C) was used. Inclusion criteria were a physician’s diagnosis of COPD and age ≥40 years. Subjects with a history of lung surgery, lung cancer or COPD exacerbation within the last four weeks were excluded.

Results

Sixty-seven pulmonologists and 6 GPs enrolled 1175 COPD patients. Two hundred forty-eight of those did not fulfill GOLD criteria for COPD (FEV₁/FVC <0.7) and 77 were excluded due to missing data. Finally, 850 patients (62.8% men; mean age 66.2 ± 0.3 (SE) years; mean FEV₁%pred. 51.5 ± 0.6 (SE)) were analyzed. Last year, 55.4% reported at least one exacerbation, and 12.7% were hospitalized for COPD exacerbation. Mean SGRQ-C total score was 43.1 ± 0.83 (SE) and mean component scores for symptoms, activity and impacts were 55.6, 55.4 and 30.5, respectively. Half of the patients (50.3%) reported not being able to do any sports and 78.7% stated that their respiratory symptoms did not allow them doing anything they would like to do. In patients with less severe COPD (FEV₁pred ≥50% and non-frequent exacerbations), global health status was overrated, ie, estimated as better by the physician than by the patient, while it was underrated in more severe COPD.

Conclusion

In Austria, the burden of disease in COPD outpatients tends to be underestimated in patients with milder airway obstruction and less exacerbations and overestimated in patients with more severe airway obstruction and frequent exacerbations. Our finding suggests that validated assessment of global health status might decrease these differences of perception.

Differences in diagnostic patterns of obstructive airway disease between areas and sex in Sweden and Finland - the Nordic EpiLung study

OBJECTIVE

To investigate the current prevalence of physician-diagnosed obstructive airway diseases by respiratory symptoms and by sex in Sweden and Finland.

METHOD

In 2016, a postal questionnaire was answered by 34,072 randomly selected adults in four study areas: Västra Götaland and Norrbotten in Sweden, and Seinäjoki-Vaasa and Helsinki in Finland.

RESULTS

The prevalence of asthma symptoms was higher in Norrbotten (13.2%), Seinäjoki-Vaasa (14.8%) and Helsinki (14.4%) than in Västra Götaland (10.7%), and physician-diagnosed asthma was highest in Norrbotten (13.0%) and least in Västra Götaland (10.1%). Chronic productive cough was most common in the Finnish areas (7.7-8.2% versus 6.3-6.7%) while the prevalence of physician-diagnosed chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) varied between 1.7 and 2.7% in the four areas. Among individuals with respiratory symptoms, the prevalence of asthma was most common in Norrbotten, while a diagnosis of COPD or CB was most common in Västra Götaland and Seinäjoki-Vaasa. More women than men with respiratory symptoms reported a diagnosis of asthma in Sweden and Seinäjoki-Vaasa but there were no sex differences in Helsinki. In Sweden, more women than men with symptoms of cough or phlegm reported a diagnosis of CB or COPD, while in Finland the opposite was found.

CONCLUSION

The prevalence of respiratory symptoms and corresponding diagnoses varied between and within the countries. The proportion reporting a diagnosis of obstructive airway disease among individuals with respiratory symptoms varied, indicating differences in diagnostic patterns both between areas and by sex.

Treatment with inhaled corticosteroids in chronic obstructive pulmonary disease

In chronic obstructive pulmonary disease (COPD), treatment with inhaled corticosteroids (ICSs) in combination with long acting beta-2-agonists (LABA) or LABA/long-acting muscarinic antagonists (LAMA) is used in order to reduce exacerbations. Treatment with ICS is, however, associated with side effects such as oropharyngeal candidiasis, skin thinning or easy bruising and pneumonia. The aim of this review was to investigate when to use ICS in COPD and to compare the effectiveness and safety of different ICSs. Studies comparing the effect of ICS/LABA and LABA/LAMA on exacerbations have shown divergent results, whereas most studies comparing ICS/LABA/LAMA (triple therapy) with LABA/LAMA have reported fewer exacerbations with triple therapy. Several investigations have shown that the number of eosinophils in blood predicts whether a patient will benefit from treatment with ICS. There is also data indicating that ICS has a small but significant positive effect on lung function decline and decrease mortality. There are four observational studies showing a better effect on exacerbations with budesonide/formoterol than fluticasone propionate/salmeterol and three observational studies showing less risk of pneumonia with budesonide than fluticasone propionate. Studies comparing the effect and safety of other ICSs such as fluticasone furoate and beclomethasone are too few to draw firm conclusions from. In conclusion, ICS together with LABA or LABA/LAMA reduces the risk of exacerbations in COPD. The indication of using ICS in COPD is stronger if the patient has increased blood eosinophils levels. There are data indicating that the choice of ICS matters, with studies showing a better effect-safety profile with budesonide compared to fluticasone propionate whereas it is not possible to make benefit-risk comparisons between the other licensed ICSs.

Prevalence of Airflow Obstruction as Measured by Spirometry, in Rural Southern Indian Adults

Rural population-based estimates of airflow obstruction based on spirometry are unavailable from southern India. This study assessed the prevalence of spirometry-defined airflow obstruction in Vellore, Tamil Nadu.A cross sectional survey was done in nine villages, among adults aged ≥30 years, where previous cardiovascular surveys had been conducted (1994, 2011). Population proportional to size sampling was used to select 20 clusters, with sampling from all streets proportional to the number of households. One person randomly selected per household was interviewed for symptoms and risk factors. A respiratory therapist performed pre and post bronchodilator spirometry on all, following American Thoracic Society criteria. Airflow obstruction was defined as pre-bronchodilator Forced Expiratory Volume 1 s/Forced Vital Capacity (FEV1/FVC) < Lower Limit of Normal (LLN, derived from local prediction equations) and compared to other criteria.Of 1015 participants, 787 completed technically acceptable spirometry. The prevalence of airflow obstruction was 9.0% (95% CI: 5.8%-9.6%, 71). Fixed obstruction (post bronchodilator FEV1/FVC < LLN) was 4.6% (95% CI: 3.1%-6.1%, 36), and 4.1% (95% CI: 2.7%-5.5%, 32) using post bronchodilator FEV1/FVC < 70%. The GOLD criteria missed 56% (40) of those with airflow obstruction, of which 87.5% were females. Although 63.4% with airflow obstruction had moderate to severe disease, 82.2% were not on treatment and only 48.9% reported symptoms in the previous year.This study estimates prevalence of airflow obstruction based on spirometry in rural southern India. Despite significant impairment on spirometry, majority were undiagnosed, and half did not report symptoms.

Lifetime Occupational History, Respiratory Symptoms and Chronic Obstructive Pulmonary Disease: Results from a Population-Based Study

Purpose

To ascertain the effect of lifelong occupational history, ambient air pollution, and biochemically verified smoking status on chronic obstructive pulmonary disease (COPD) in a general population of one the largest cities in Central Asia, Almaty.

Patients and methods

1500 adults (median age 49, interquartile range (IQR) 28 years), 50% females, were randomly selected from a registry of enlisted population of a primary care facility in Almaty, Kazakhstan and they filled in the questionnaire on demographics, respiratory symptoms (CAT and mMRC), smoking status, verified by exhaled carbon monoxide, and detailed lifetime occupational history. COPD was defined as postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) below lower limit of normal (LLN) using Belintelmed MAS-2 spirometer (Belarus).

Results

230 (15%) subjects had CAT≥10; 136 (9%) participants had mMRC score ≥2. Greater CAT score was associated with age, smaller income, and less exercise, but not with smoking or living closer to a major road. 26% of the population was ever exposed to vapors, gases, dusts, and fumes (VGDF). In age group 40 years and above (N=1024), COPD was found in 57 participants (prevalence 5.6%), more in men (8.7% vs 3.4%). In the multivariate model adjusted for age, sex, ever-smoking, income, and exercise, any exposure to VGDF increased the odds of COPD (odds ratio (OR) 1.71; 95% confidence interval (CI) 1.03; 2.84), more in the highest exposure category (OR 2.36 (95% CI 1.20; 4.66)).

Conclusion

Lifetime exposure to VGDF, found in ¼ of the general population, increased the odds of COPD independent of smoking by 71%.

COPD overdiagnosis in primary care: a UK observational study of consistency of airflow obstruction

Chronic obstructive pulmonary disease (COPD) is heterogeneous, but persistent airflow obstruction (AFO) is fundamental to diagnosis. We studied AFO consistency from initial diagnosis and explored factors associated with absent or inconsistent AFO. This was a retrospective observational study using patient-anonymised routine individual data in Care and Health Information Analytics (CHIA) database. Identifying a prevalent COPD cohort based on diagnostic codes in primary care records, we used serial ratios of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC%) from time of initial COPD diagnosis to assign patients to one of three AFO categories, according to whether all (persistent), some (variable) or none (absent) were <70%. We described respiratory prescriptions over 3 years (2011-2013) and used multivariable logistic regression to estimate odds of absent or variable AFO and potential predictors. We identified 14,378 patients with diagnosed COPD (mean ± SD age 68.8 ± 10.7 years), median (IQR) COPD duration of 60 (25,103) months. FEV1/FVC% was recorded in 12,491 (86.9%) patients: median (IQR) 5 (3, 7) measurements. Six thousand five hundred and fifty (52.4%) had persistent AFO, 4507 (36.1%) variable AFO and 1434 (11.5%) absent AFO. Being female, never smoking, having higher BMI or more comorbidities significantly predicted absent and variable AFO. Despite absent AFO, 57% received long-acting bronchodilators and 60% inhaled corticosteroids (50% and 49%, respectively, in those without asthma). In all, 13.1% of patients diagnosed with COPD had unrecorded FEV1/FVC%; 11.5% had absent AFO on repeated measurements, yet many received inhalers likely to be ineffective. Such prescribing is not evidence based and the true cause of symptoms may have been missed.