Diagnostic accuracy of screening tests for COPD: a systematic review and meta-analysis

Development and application of a deep learning-based comprehensive early diagnostic model for chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a frequently diagnosed yet treatable condition, provided it is identified early and managed effectively. This study aims to develop an advanced COPD diagnostic model by integrating deep learning and radiomics features.

METHODS

We utilized a dataset comprising CT images from 2,983 participants, of which 2,317 participants also provided epidemiological data through questionnaires. Deep learning features were extracted using a Variational Autoencoder, and radiomics features were obtained using the PyRadiomics package. Multi-Layer Perceptrons were used to construct models based on deep learning and radiomics features independently, as well as a fusion model integrating both. Subsequently, epidemiological questionnaire data were incorporated to establish a more comprehensive model. The diagnostic performance of standalone models, the fusion model and the comprehensive model was evaluated and compared using metrics including accuracy, precision, recall, F1-score, Brier score, receiver operating characteristic curves, and area under the curve (AUC).

RESULTS

The fusion model exhibited outstanding performance with an AUC of 0.952, surpassing the standalone models based solely on deep learning features (AUC = 0.844) or radiomics features (AUC = 0.944). Notably, the comprehensive model, incorporating deep learning features, radiomics features, and questionnaire variables demonstrated the highest diagnostic performance among all models, yielding an AUC of 0.971.

CONCLUSION

We developed and implemented a data fusion strategy to construct a state-of-the-art COPD diagnostic model integrating deep learning features, radiomics features, and questionnaire variables. Our data fusion strategy proved effective, and the model can be easily deployed in clinical settings.

TRIAL REGISTRATION

Not applicable. This study is NOT a clinical trial, it does not report the results of a health care intervention on human participants.

Budget impact analysis of adopting primary care-based case detection of chronic obstructive pulmonary disease in the Canadian general population

BACKGROUND

An estimated 70% of Canadians with chronic obstructive pulmonary disease (COPD) have not received a diagnosis, creating a barrier to early intervention, and there is growing interest in the value of primary care-based opportunistic case detection for COPD. We sought to build on a previous cost-effectiveness analysis by evaluating the budget impact of adopting COPD case detection in the Canadian general population.

METHODS

We used a validated discrete-event microsimulation model of COPD in the Canadian general population aged 40 years and older to assess the costs of implementing 8 primary care-based case detection strategies over 5 years (2022-2026) from the health care payer perspective. Strategies varied in eligibility criteria (based on age, symptoms or smoking history) and testing technology (COPD Diagnostic Questionnaire [CDQ] or screening spirometry). Costs were determined from Canadian studies and converted to 2021 Canadian dollars. Key parameters were varied in one-way sensitivity analysis.

RESULTS

All strategies resulted in higher total costs compared with routine diagnosis. The most cost-effective scenario (the CDQ for all patients) had an associated total budget expansion of $423 million, with administering case detection and subsequent diagnostic spirometry accounting for 86% of costs. This strategy increased the proportion of individuals diagnosed with COPD from 30.4% to 37.8%, and resulted in 4.6 million referrals to diagnostic spirometry. Results were most sensitive to uptake in primary care.

INTERPRETATION

Adopting a national COPD case detection program would be an effective method for increasing diagnosis of COPD, dependent on successful uptake. However, it will require prioritisation by budget holders and substantial additional investment to improve access to diagnostic spirometry.

Impact of a Computerized Clinical Decision Support System to Improve Chronic Obstructive Pulmonary Disease Diagnosis and Testing for Alpha-1 Antitrypsin Deficiency

Rationale: Chronic obstructive pulmonary disease (COPD) and alpha-1 antitrypsin deficiency (AATD) are underrecognized diseases. This is in part due to the underdiagnosis and lack of confirmation of COPD but also from poor adherence to AATD screening recommendations. Objectives: A clinical decision support system (CDSS) to guide primary care providers improves spirometry testing and confirmation of COPD diagnosis in subjects at risk and improves AATD screening in patients with confirmed COPD. Methods: A CDSS was created to be applied to all Veterans attending single-center Veterans Affairs primary care clinics. The CDSS had an algorithmic dialogue with components executed in phases during different clinic visits: screening for COPD risk using the COPD population screening (COPD-PS) questionnaire, spirometry recommendation, and ordering tool for subjects with a prior diagnosis of COPD or subjects considered high risk by the COPD-PS, dialogue to confirm or discard the diagnosis of COPD, and recommendations for AATD screening in subjects with confirmed COPD. The latter was performed by ordering alpha-1 antitrypsin (AAT) serum levels. Each step of the CDSS algorithm approach was recorded and available to be retrieved at a later date for analysis. Results: Over 6 years, a total of 6,235 Veterans >40 years of age completed the CDSS. According to the COPD-PS questionnaire, 962 (18.5%) subjects were identified as high risk for COPD. An additional 579 subjects with a prior diagnosis of COPD also entered the subsequent steps of the CDSS algorithm. Of the high-risk cohort, the CDSS led to an increase in spirometry testing from 24% to 83% and led to a new diagnosis of COPD in 342 (43%). In the prior COPD diagnosis group, spirometry testing increased from 58% to 84%, leading to COPD reconfirmation in only 326 (67%). A total of 489 (68%) subjects with confirmed COPD completed AAT testing prompted by the CDSS, with 23 subjects identified with AATD and one with severe AATD. Conclusions: In the Veterans Affairs system, the use of a clinical decision support system algorithm that incorporates screening for COPD and AATD improves COPD over- and underdiagnosis and screening rates of AATD in a primary care setting.

Implementation of a screening and management pathway for chronic obstructive pulmonary disease in patients with atrial fibrillation

AIMS

Chronic obstructive pulmonary disease (COPD) negatively impacts the efficacy of heart rhythm control treatments in patients with atrial fibrillation (AF). Although COPD is recognized as a risk factor for AF, practical guidance about how and when to screen for COPD is not available. Herein, we describe the implementation of an integrated screening and management pathway for COPD into the existing pre-ablation work-up in an AF outpatient clinic infrastructure.

METHODS AND RESULTS

Consecutive unselected patients accepted for AF catheter ablation in the Maastricht University Medical Center+ were prospectively screened for airflow limitation using handheld (micro)spirometry at the pre-ablation outpatient clinic supervised by an AF nurse. Patients with results suggestive of airflow limitation were offered referral to the pulmonologist. Handheld (micro)spirometry was performed in 232 AF patients, which provided interpretable results in 206 (88.8%) patients. Airflow limitation was observed in 47 patients (20.3%). Out of these 47 patients, 29 (62%) opted for referral to the pulmonologist. The primary reason for non-referral was low perceived symptom burden. Using this screening strategy 17 (out of 232; 7.3%) ultimately received a diagnosis of chronic respiratory disease, either COPD or asthma.

CONCLUSION

A COPD care pathway can successfully be embedded in an existing AF outpatient clinic infrastructure, using (micro)spirometry and remote analysis of results. Although one out of five patients had results suggestive of an underlying chronic respiratory disease, only 62% of these patients opted for a referral. Pre-selection of patients as well as patient education might increase the diagnostic yield and requires further research.

Spirometry in atrial fibrillation: what's the catch?

INTRODUCTION

People with COPD rarely have COPD alone, and the commonest co-morbidities occurring with COPD are cardiovascular. Whilst multiple studies have explored the association between major cardiovascular events and COPD, less attention has been paid to arrhythmias, specifically atrial fibrillation (AF). AF and COPD frequently occur together, posing challenges in diagnosis and management. In this review, we describe the relationship between AF and COPD epidemiologically and physiologically, demonstrating the role of spirometry as a diagnostic and disease management tool.

AREAS COVERED

We provide epidemiological evidence that COPD and AF are independent risk factors for one another, that either disease is highly prevalent amongst people with the other, and that they have shared risk factors; all of which contribute to adverse prognostic. We elucidated common pathophysiological mechanisms implicated in AF-COPD. We ultimately present the epidemiological and physiological evidence with a view to highlight specific areas where we feel spirometry is of value in the management of AF-COPD.

EXPERT OPINION

AF and COPD commonly co-occur, there is often diagnostic delay, increased risk of reduced cardioversion success, and missed opportunity to intervene to reduce stroke risk. Greater awareness and timelier diagnosis and guideline directed management may improve outcomes for people with both diseases.

Undiagnosed chronic respiratory disorders in symptomatic patients with initially suspected and excluded coronary artery disease: insights from a prospective pilot study

Background

Chronic respiratory diseases represent the third-leading cause of death on a global scale. Due to mutual symptoms with cardiovascular diseases and potential inappropriate attribution of symptoms, pulmonary diseases often remain undiagnosed. Therefore, we aimed to evaluate the prevalence of chronic respiratory disorders among symptomatic patients in whom suspected coronary artery disease (CAD) was ruled out.

Methods

After CAD was excluded by invasive coronary angiography (ICA), 50 patients with chest pain or dyspnea were prospectively enrolled in this study. All patients underwent lung function testing, including spirometry and diffusion measurements. At baseline and the 3-month follow-up, standardized assessments of symptoms (CCS chest pain, mMRC score, CAT score) were performed.

Results

Chronic respiratory disease was diagnosed in 14% of patients, with a prevalence of 6% for chronic obstructive ventilation disorders. At 3-month follow-up, patients with normal lung function tests revealed a substantial improvement in symptoms (mean mMRC 0.70 to 0.33, p = 0.06; median CAT 8 to 2, p = 0.01), while those with pulmonary findings showed non-significant alterations or unchanged symptoms (mean mMRC 1.14 to 0.71, p = 0.53; median CAT 6 to 6, p = 0.52).

Conclusion

A substantial proportion of patients with an initial suspicion of coronary artery disease was diagnosed with underlying chronic respiratory diseases and exhibited persistent symptoms.

Accuracy and economic evaluation of screening tests for undiagnosed COPD among hypertensive individuals in Brazil

In Brazil, prevalence of diagnosed COPD among adults aged 40 years and over is 16% although over 70% of cases remain undiagnosed. Hypertension is common and well-recorded in primary care, and frequently co-exists with COPD because of common causes such as tobacco smoking, therefore we conducted a cross-sectional screening test accuracy study in nine Basic Health Units in Brazil, among hypertensive patients aged ≥40 years to identify the optimum screening test/combinations to detect undiagnosed COPD. We compared six index tests (four screening questionnaires, microspirometer and peak flow) against the reference test defined as those below the lower limit of normal (LLN-GLI) on quality diagnostic spirometry, with confirmed COPD at clinical review. Of 1162 participants, 6.8% (n = 79) had clinically confirmed COPD. Peak flow had a higher specificity but lower sensitivity than microspirometry (sensitivity 44.3% [95% CI 33.1, 55.9], specificity 95.5% [95% CI 94.1, 96.6]). SBQ performed well compared to the other questionnaires (sensitivity 75.9% [95% CI 65.0, 84.9], specificity 59.2% [95% CI 56.2, 62.1]). A strategy requiring both SBQ and peak flow to be positive yielded sensitivity of 39.2% (95% CI 28.4, 50.9) and specificity of 97.0% (95% CI 95.7, 97.9). The use of simple screening tests was feasible within the Brazilian primary care setting. The combination of SBQ and peak flow appeared most efficient, when considering performance of the test, cost and ease of use (costing £1690 (5554 R$) with 26.7 cases detected per 1,000 patients). However, the choice of screening tests depends on the clinical setting and availability of resources.ISRCTN registration number: 11377960.

Machine-learning algorithms for asthma, COPD, and lung cancer risk assessment using circulating microbial extracellular vesicle data and their application to assess dietary effects

Although mounting evidence suggests that the microbiome has a tremendous influence on intractable disease, the relationship between circulating microbial extracellular vesicles (EVs) and respiratory disease remains unexplored. Here, we developed predictive diagnostic models for COPD, asthma, and lung cancer by applying machine learning to microbial EV metagenomes isolated from patient serum and coded by their accumulated taxonomic hierarchy. All models demonstrated high predictive strength with mean AUC values ranging from 0.93 to 0.99 with various important features at the genus and phylum levels. Application of the clinical models in mice showed that various foods reduced high-fat diet-associated asthma and lung cancer risk, while COPD was minimally affected. In conclusion, this study offers a novel methodology for respiratory disease prediction and highlights the utility of serum microbial EVs as data-rich features for noninvasive diagnosis.

Artificial intelligence (AI) has enabled researchers to intercept microbial messages bearing clinically useful information about of a variety of respiratory disorders. The organisms that comprise our microbiome communicate via the release of tiny, biomolecule-laden membrane bubbles called ‘extracellular vesicles’ (EVs) into the bloodstream. EVs are also influenced by human disease. South Korean researchers led by Yoon-Keun Kim of MD Healthcare, Seoul, and Young-Koo Jee of Dankook University College of Medicine, Cheonan, have used an AI algorithm to assemble EV-based profiles that can discriminate between healthy people and those with conditions like asthma or lung cancer. Their analysis of 1727 patient serum samples revealed microbial signatures that enabled accurate diagnosis of several respiratory disorders. Preliminary experiments in mice suggest that certain dietary changes could help shift the microbiome of high-risk individuals towards a healthier profile.

Accuracy of portable spirometers in the diagnosis of chronic obstructive pulmonary disease A meta-analysis

Portable spirometers has been approved for diagnosing chronic obstructive pulmonary disease (COPD). However, their diagnostic accuracy has not been reviewed. Therefore, the purpose of this study was to systematically evaluate the diagnostic value of portable spirometers in detecting COPD. A comprehensive literature search for relevant studies was conducted in PubMed, Embase, CNKI, Wan Fang, and Web of Science databases. Pooled sensitivity, specificity, summary receiver operating characteristic (SROC), area under the curve (AUC), and other related indices were calculated using the bivariate mixed-effect model. Subgroup analysis was performed to explore the source of heterogeneity. Thirty one studies were included in the meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic ratio (DOR), SROC, and AUC of the SROC of portable spirometers were 0.85 (0.81–0.88), 0.85 (0.81–0.88), 5.6 (4.4–7.3), 0.18 (0.15–0.22), 31 (21–46) and 0.91 (0.89–0.94), respectively. Among the three commonly used types of portable spirometers, the accuracy of PIKO-6 was higher (0.95) than that of COPD-6 (0.91) and PEF (0.82). Subgroup analysis indicated that the accuracy of a multi-indices portable spirometer was higher than that of a single-index one (P < 0.05). In addition, portable spirometry performed by professional technicians in tertiary hospitals was more accurate than for those conducted by trained technicians in primary care facilities and communities (P < 0.05). Moreover, the accuracy of studies conducted in developing country was superior to developed country (P < 0.05). Portable spirometers have high accuracy in the diagnosis of COPD. Multi-index COPD-6 and PIKO-6 displayed higher accuracy than others. Standardized training of instrument operators should be considered to achieve reliable results.

Accuracy of the COPD diagnostic questionnaire as a screening tool in primary care

BACKGROUND

The COPD Diagnostic Questionnaire (CDQ) was developed to identify people who would benefit from spirometry testing to confirm Chronic Obstructive Pulmonary Disease (COPD). The aim of this study was to determine the usefulness of a cut-off score of 16.5 on the CDQ in identifying those at increased risk of obstruction, in a mixed population of people 'at risk' of COPD and those with an 'existing' COPD diagnosis.

METHODS

People 'at risk' of COPD (aged > 40 years, current/ex-smoker) and those with 'existing' COPD were identified from four general practices and invited to participate. Participants completed the CDQ and those with a CDQ score ≥ 16.5 were categorised as having intermediate to increased likelihood of airflow obstruction. Pre and post-bronchodilator spirometry determined the presence of airway obstruction (FEV₁/FVC ratio < 0.7). Sensitivity, specificity and accuracy of the CDQ was determined compared to spirometry as the gold standard.

RESULTS

One hundred forty-one participants attended an initial assessment ('at risk' = 111 (79%), 'existing' COPD = 30 (21%)). A cut-off score of 16.5 corresponded to a sensitivity of 81%, specificity of 36% and accuracy of 50%, in the entire mixed population. The area under the ROC curve was 0.59 ± 0.50 indicating low diagnostic accuracy of the CDQ. Similar results were found in the 'existing' COPD group alone.

CONCLUSION

Whilst a cut-off score of 16.5 on the CDQ may result in a large number of false positives, clinicians may still wish to use the CDQ to refine who receives spirometry due to its high sensitivity.

TRIAL REGISTRATION

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

Performance and Clinical Utility of Various Chronic Obstructive Pulmonary Disease Case-Finding Tools

BACKGROUND AND AIM

Chronic obstructive pulmonary disease (COPD) is frequently underdiagnosed because of the unavailability of spirometers, especially in resource-limited outpatient settings. This study provides real-world evidence to identify optimal approaches for COPD case finding in outpatient settings.

METHODS

This retrospective study enrolled individuals who were at risk of COPD (age ≥40 years, ≥10 pack-years, and ≥1 respiratory symptom). Eligible participants were examined using various COPD case-finding tools, namely the COPD Population Screener (COPD-PS) questionnaire, a COPD prediction (PCOPD) model, and a microspirometer, Spirobank Smart; subsequently, the participants underwent confirmatory spirometry. The definition and confirmation of COPD were based on conventional spirometry. Receiver operating characteristic curve (ROC), area under the curve (AUC), and decision curve analyses were conducted, and a clinical impact curve was constructed.

RESULTS

In total, 385 participants took part in the study [284 without COPD (73.77%) and 101 with COPD (26.23%)]. The microspirometer exhibited a higher AUC value than did the COPD-PS questionnaire and the PCOPD model. The AUC for microspirometry was 0.908 (95% confidence interval [CI] = 0.87-0.95), that for the PCOPD model was 0.788 (95% CI = 0.74-0.84), and that for the COPD-PS questionnaire was 0.726 (95% CI = 0.67-0.78). Decision and clinical impact curve analyses revealed that a microspirometry-derived FEV1/FVC ratio of <74% had superior clinical utility to the other measurement tools.

CONCLUSION

The PCOPD model and COPD-PS questionnaire were useful for identifying symptomatic patients likely to have COPD, but microspirometry was more accurate and had higher clinical utility. This study provides real-world evidence to identify optimal practices for COPD case finding; such practices ensure that physicians have convenient access to up-to-date evidence when they encounter a symptomatic patient likely to have COPD.

Case-finding and improving patient outcomes for chronic obstructive pulmonary disease in primary care: the BLISS research programme including cluster RCT

Background

Chronic obstructive pulmonary disease is a major contributor to morbidity, mortality and health service costs but is vastly underdiagnosed. Evidence on screening and how best to approach this is not clear. There are also uncertainties around the natural history (prognosis) of chronic obstructive pulmonary disease and how it impacts on work performance.

Objectives

Work package 1: to evaluate alternative methods of screening for undiagnosed chronic obstructive pulmonary disease in primary care, with clinical effectiveness and cost-effectiveness analyses and an economic model of a routine screening programme. Work package 2: to recruit a primary care chronic obstructive pulmonary disease cohort, develop a prognostic model [Birmingham Lung Improvement StudieS (BLISS)] to predict risk of respiratory hospital admissions, validate an existing model to predict mortality risk, address some uncertainties about natural history and explore the potential for a home exercise intervention. Work package 3: to identify which factors are associated with employment, absenteeism, presenteeism (working while unwell) and evaluate the feasibility of offering formal occupational health assessment to improve work performance.

Design

Work package 1: a cluster randomised controlled trial with household-level randomised comparison of two alternative case-finding approaches in the intervention arm. Work package 2: cohort study – focus groups. Work package 3: subcohort – feasibility study.

Setting

Primary care settings in West Midlands, UK.

Participants

Work package 1: 74,818 people who have smoked aged 40–79 years without a previous chronic obstructive pulmonary disease diagnosis from 54 general practices. Work package 2: 741 patients with previously diagnosed chronic obstructive pulmonary disease from 71 practices and participants from the work package 1 randomised controlled trial. Twenty-six patients took part in focus groups. Work package 3: occupational subcohort with 248 patients in paid employment at baseline. Thirty-five patients took part in an occupational health intervention feasibility study.

Interventions

Work package 1: targeted case-finding – symptom screening questionnaire, administered opportunistically or additionally by post, followed by diagnostic post-bronchodilator spirometry. The comparator was routine care. Work package 2: twenty-three candidate variables selected from literature and expert reviews. Work package 3: sociodemographic, clinical and occupational characteristics; occupational health assessment and recommendations.

Main outcome measures

Work package 1: yield (screen-detected chronic obstructive pulmonary disease) and cost-effectiveness of case-finding; effectiveness of screening on respiratory hospitalisation and mortality after approximately 4 years. Work package 2: respiratory hospitalisation within 2 years, and barriers to and facilitators of physical activity. Work package 3: work performance – feasibility and acceptability of the occupational health intervention and study processes.

Results

Work package 1: targeted case-finding resulted in greater yield of previously undiagnosed chronic obstructive pulmonary disease than routine care at 1 year [n = 1278 (4%) vs. n = 337 (1%), respectively; adjusted odds ratio 7.45, 95% confidence interval 4.80 to 11.55], and a model-based estimate of a regular screening programme suggested an incremental cost-effectiveness ratio of £16,596 per additional quality-adjusted life-year gained. However, long-term follow-up of the trial showed that at ≈4 years there was no clear evidence that case-finding, compared with routine practice, was effective in reducing respiratory admissions (adjusted hazard ratio 1.04, 95% confidence interval 0.73 to1.47) or mortality (hazard ratio 1.15, 95% confidence interval 0.82 to 1.61). Work package 2: 2305 patients, comprising 1564 with previously diagnosed chronic obstructive pulmonary disease and 741 work package 1 participants (330 with and 411 without obstruction), were recruited. The BLISS prognostic model among cohort participants with confirmed airflow obstruction (n = 1894) included 6 of 23 candidate variables (i.e. age, Chronic Obstructive Pulmonary Disease Assessment Test score, 12-month respiratory admissions, body mass index, diabetes and forced expiratory volume in 1 second percentage predicted). After internal validation and adjustment (uniform shrinkage factor 0.87, 95% confidence interval 0.72 to 1.02), the model discriminated well in predicting 2-year respiratory hospital admissions (c-statistic 0.75, 95% confidence interval 0.72 to 0.79). In focus groups, physical activity engagement was related to self-efficacy and symptom severity. Work package 3: in the occupational subcohort, increasing dyspnoea and exposure to inhaled irritants were associated with lower work productivity at baseline. Longitudinally, increasing exacerbations and worsening symptoms, but not a decline in airflow obstruction, were associated with absenteeism and presenteeism. The acceptability of the occupational health intervention was low, leading to low uptake and low implementation of recommendations and making a full trial unfeasible.

Limitations

Work package 1: even with the most intensive approach, only 38% of patients responded to the case-finding invitation. Management of case-found patients with chronic obstructive pulmonary disease in primary care was generally poor, limiting interpretation of the long-term effectiveness of case-finding on clinical outcomes. Work package 2: the components of the BLISS model may not always be routinely available and calculation of the score requires a computerised system. Work package 3: relatively few cohort participants were in paid employment at baseline, limiting the interpretation of predictors of lower work productivity.

Conclusions

This programme has addressed some of the major uncertainties around screening for undiagnosed chronic obstructive pulmonary disease and has resulted in the development of a novel, accurate model for predicting respiratory hospitalisation in people with chronic obstructive pulmonary disease and the inception of a primary care chronic obstructive pulmonary disease cohort for longer-term follow-up. We have also identified factors that may affect work productivity in people with chronic obstructive pulmonary disease as potential targets for future intervention.

Future work

We plan to obtain data for longer-term follow-up of trial participants at 10 years. The BLISS model needs to be externally validated. Our primary care chronic obstructive pulmonary disease cohort is a unique resource for addressing further questions to better understand the prognosis of chronic obstructive pulmonary disease.

Trial registration

Current Controlled Trials ISRCTN14930255.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 13. See the NIHR Journals Library website for further project information.

Accuracy and cost-effectiveness of different screening strategies for identifying undiagnosed COPD among primary care patients (≥40 years) in China: a cross-sectional screening test accuracy study: findings from the Breathe Well group

OBJECTIVES

To examine the accuracy and cost-effectiveness of various chronic obstructive pulmonary disease (COPD) screening tests and combinations within a Chinese primary care population.

DESIGN

Screening test accuracy study.

SETTING

Urban and rural community health centres in four municipalities of China: Beijing (north), Chengdu (southwest), Guangzhou (south) and Shenyang (northeast).

PARTICIPANTS

Community residents aged 40 years and above who attended community health centres for any reason were invited to participate. 2445 participants (mean age 59.8 (SD 9.6) years, 39.1% (n=956) male) completed the study (February-December 2019), 68.9% (n=1684) were never-smokers and 3.6% (n=88) had an existing COPD diagnosis. 13.7% (n=333) of participants had spirometry-confirmed airflow obstruction.

INTERVENTIONS

Participants completed six index tests (screening questionnaires (COPD Diagnostic Questionnaire, COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE), Chinese Symptom-Based Questionnaire (C-SBQ), COPD-SQ), microspirometry (COPD-6), peak flow (model of peak flow meters used in the study (USPE)) and the reference test (ndd Easy On-PC).

PRIMARY AND SECONDARY OUTCOMES

Cases were defined as those with forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) below the lower limit of normal (LLN-GLI) on the reference test. Performance of individual screening tests and their combinations was evaluated, with cost-effectiveness analyses providing cost per additional true case detected.

RESULTS

Airflow measurement devices (sensitivities 64.9% (95% CI 59.5% to 70.0%) and 67.3% (95% CI 61.9% to 72.3%), specificities 89.7% (95% CI 88.4% to 91.0%) and 82.6% (95% CI 80.9% to 84.2%) for microspirometry and peak flow, respectively) generally performed better than questionnaires, the most accurate of which was C-SBQ (sensitivity 63.1% (95% CI 57.6% to 68.3%) specificity 74.2% (95% CI 72.3% to 76.1%)). The combination of C-SBQ and microspirometry used in parallel maximised sensitivity (81.4%) (95% CI 76.8% to 85.4%) and had specificity of 68.0% (95% CI 66.0% to 70.0%), with an incremental cost-effectiveness ratio of £64.20 (CNY385) per additional case detected compared with peak flow.

CONCLUSIONS

Simple screening tests to identify undiagnosed COPD within the primary care setting in China is possible, and a combination of C-SBQ and microspirometry is the most sensitive and cost-effective. Further work is required to explore optimal cut-points and effectiveness of programme implementation.

TRIAL REGISTRATION NUMBER

ISRCTN13357135.

Diagnostic accuracy of screening tools for chronic obstructive pulmonary disease in primary health care: Rapid evidence synthesis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) contributed significantly to burden of diseases in India, with missed, incorrect, and delayed diagnosis in primary care. We conducted a rapid evidence synthesis, to summarize the evidence on accuracy of the screening tests for COPD in primary health care on request form State Health Resource Centre, Chhattisgarh.

METHODS

Considering the rapid nature of decision making, our approach was to first search for existing systematic reviews. We identified one existing systematic review on the topic with the search conducted until 2014. We updated the review by searching in two major databases screened, title/abstracts, and full texts of studies as per eligibility criteria and extracted relevant data. A narrative synthesis was conducted.

RESULTS

We retrieved 7,007 and included five new studies, to add to 10 studies of the existing systematic review. Overall, 13 studies assessed diagnostic accuracy of screening questionnaires [e.g., COPD Diagnostic Questionnaire (CDQ)], five assessed handheld flow meters (COPD6 and PICO-6), and four assessed the combination of both the tests. The CDQ questionnaire using a score threshold ≥16.5 or >17 demonstrated comparatively a higher sensitivity both in pooled result for ever-smokers [87.5% (95% CI 83.1--90.9%)] and among the adults >35 years [73.8--93% (95% CI 69--98%)] when compared to a different score threshold of CDQ and other questionnaires. Handheld flow meters reported a pooled high sensitivity of 79.9% (95% CI 74.2--84.7%) in ever-smokers and 87.9% in adults with age >35 years.

CONCLUSIONS

The need for better diagnosis of COPD in primary healthcare can be addressed by using of COPD Diagnostic Questionnaire alone or in combination with hand-held flow meters. There is scope for more implementation research on the domain.

Chronic obstructive pulmonary disease and atrial fibrillation: an interdisciplinary perspective

Chronic obstructive pulmonary disease (COPD) is highly prevalent among patients with atrial fibrillation (AF), shares common risk factors, and adds to the overall morbidity and mortality in this population. Additionally, it may promote AF and impair treatment efficacy. The prevalence of COPD in AF patients is high and is estimated to be ∼25%. Diagnosis and treatment of COPD in AF patients requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and pulmonologist. Differential diagnosis may be challenging, especially in elderly and smoking patients complaining of unspecific symptoms such as dyspnoea and fatigue. Routine evaluation of lung function and determination of natriuretic peptides and echocardiography may be reasonable to detect COPD and heart failure as contributing causes of dyspnoea. Acute exacerbation of COPD transiently increases AF risk due to hypoxia-mediated mechanisms, inflammation, increased use of beta-2 agonists, and autonomic changes. Observational data suggest that COPD promotes AF progression, increases AF recurrence after cardioversion, and reduces the efficacy of catheter-based antiarrhythmic therapy. However, it remains unclear whether treatment of COPD improves AF outcomes and which metric should be used to determine COPD severity and guide treatment in AF patients. Data from non-randomized studies suggest that COPD is associated with increased AF recurrence after electrical cardioversion and catheter ablation. Future prospective cohort studies in AF patients are needed to confirm the relationship between COPD and AF, the benefits of treatment of either COPD or AF in this population, and to clarify the need and cost-effectiveness of routine COPD screening.

Performance of alternative COPD case-finding tools: a systematic review and meta-analysis

RATIONALE

Guidelines recommend pre-/post-bronchodilator spirometry for diagnosing COPD, but resource constraints limit the availability of spirometry in primary care in low- and middle-income countries. Although spirometry is the diagnostic gold standard, we shall assess alternative tools for settings without spirometry.

METHODS

A systematic literature review and meta-analysis was conducted, utilising Cochrane, CINAHL, Google Scholar, PubMed and Web of Science (search cut-off was May 01, 2020). Published studies comparing the accuracy of diagnostic tools for COPD with post-bronchodilator spirometry were considered. Studies without sensitivity/specificity data, without a separate validation sample and outside of primary care were excluded. Sensitivity, specificity and area under the curve (AUC) were assessed.

RESULTS

Of 7578 studies, 24 were included (14 635 participants). Hand devices yielded a larger AUC than questionnaires. The meta-analysis included 17 studies and the overall AUC of micro-spirometers (0.84, 95% CI 0.80-0.89) was larger when compared to the COPD population screener (COPD-PS) questionnaire (0.77, 95% CI 0.63-0.85) and the COPD diagnostic questionnaire (CDQ) (0.72, 95% CI 0.64-0.78). However, only the difference between micro-spirometers and the CDQ was significant.

CONCLUSIONS

The CDQ and the COPD-PS questionnaire were approximately equally accurate tools. Questionnaires ensured testing of symptomatic patients, but micro-spirometers were more accurate. A combination could increase accuracy but was not evaluated in the meta-analysis.

Cost-effectiveness analysis of COPD screening programs in primary care for high-risk patients in China

We built a decision-analytic model to compare the cost-effectiveness of using portable spirometer and questionnaire to screen chronic obstructive pulmonary diseases (COPD) with no screening (i.e. usual care) among chronic bronchitis patient in China. A lifetime horizon and a payer perspective were adopted. Cost data of health services including spirometry screening and treatment costs covered both maintenance and exacerbation. The result indicated that portable spirometer screening was cost-saving compared with questionnaire screening and no screening, with an incremental cost-effectiveness ratio (ICER) of −5026 and −1766 per QALY, respectively. Sensitivity analyses confirmed the robustness of the results. In summary, portable spirometer screening is likely the optimal option for COPD screening among chronic bronchitis patients China.

Identification of Patients With COPD in a Cardiac Rehabilitation Setting: THE COnCuR STUDY

PURPOSE

To examine the feasibility of screening for chronic obstructive pulmonary disease (COPD) in an outpatient cardiac rehabilitation (CR) setting and to evaluate the detection rate of COPD using a targeted screening protocol.

METHODS

A total of 95 patients (62.5 ± 10.0 yr; men, n = 77), >40-yr old with a history of smoking were included in the study sample. Each participant answered the 5-item Canadian Lung Health Test (CLHT) questionnaire assessing symptoms such as coughing, phlegm, wheezing, shortness of breath, and frequent colds. Endorsing ≥1 item was indicative of potential COPD and warranted pulmonary function testing (PFT) and/or spirometry to diagnose or rule out COPD.

RESULTS

The CLHT questionnaire identified 44 patients at risk for COPD, with an average of 1.9 ± 1.2 items endorsed. Of the patients who underwent PFT, 6 new cases of mild COPD were diagnosed, resulting in a true positive rate with CLHT screening of 19% and a false-positive rate of 81%.

CONCLUSIONS

Implementing the CLHT to patients referred to CR correctly identified COPD in <20% of cases. Using the CLHT to screen for COPD prior to starting CR may not be optimal, due to disparities between true- and false-positive rates.

Diagnostic Accuracy of a Two-Stage Sequential Screening Strategy Implemented by Community Health Workers (CHWs) to Identify Individuals with COPD in Rural India

Purpose

Undiagnosed Chronic Obstructive Pulmonary Disease (COPD) results in high morbidity, disability and mortality in India. Effective strategies for active COPD screening in community settings are needed to increase early identification, risk reduction and timely management. The objective of this study was to test the diagnostic accuracy of a sequential two-step screening strategy to detect COPD, implemented by community health workers (CHWs), among adults aged ≥40 years in a rural area of North India.

Patients and Methods

Trained CHWs screened all consenting (n=3256) eligible adults in two villages using the Lung Function Questionnaire (LFQ) to assess their COPD risk and conducted pocket spirometry on 268 randomly selected (132 with high risk ie LFQ score ≤18 and 136 with low risk ie LFQ score >18) individuals. Subsequently, trained researchers conducted post-bronchodilator spirometry on these randomly selected individuals using a diagnostic quality spirometer and confirmed the COPD diagnosis according to the Global Initiative for Obstructive Lung Disease (GOLD) criteria (FEV₁/FVC ratio <0.7).

Results

This strategy of using LFQ followed by pocket spirometry was sensitive (78.6%) and specific (78.8%), with a positive predictive value of 66% and negative predictive value of 88%. It could accurately detect 67% of GOLD Stage 1, 78% of GOLD Stage 2, 82% of GOLD Stage 3 and 100% of GOLD Stage 4 individuals with airflow limitation.

Conclusion

COPD can be accurately detected by trained CHWs using a simple sequential screening strategy. This can potentially contribute to accurate assessment of COPD and thus its effective management in low-resource settings.

Diagnostics and monitoring tools for noncommunicable diseases: a missing component in the global response

A key component of any health system is the capacity to accurately diagnose individuals. One of the six building blocks of a health system as defined by the World Health Organization (WHO) includes diagnostic tools. The WHO's Noncommunicable Disease Global Action Plan includes addressing the lack of diagnostics for noncommunicable diseases, through multi-stakeholder collaborations to develop new technologies that are affordable, safe, effective and quality controlled, and improving laboratory and diagnostic capacity and human resources. Many challenges exist beyond price and availability for the current tools included in the Package of Essential Noncommunicable Disease Interventions (PEN) for cardiovascular disease, diabetes and chronic respiratory diseases. These include temperature stability, adaptability to various settings (e.g. at high altitude), need for training in order to perform and interpret the test, the need for maintenance and calibration, and for Blood Glucose Meters non-compatible meters and test strips. To date the issues surrounding access to diagnostic and monitoring tools for noncommunicable diseases have not been addressed in much detail. The aim of this Commentary is to present the current landscape and challenges with regards to guidance from the WHO on diagnostic tools using the WHO REASSURED criteria, which define a set of key characteristics for diagnostic tests and tools. These criteria have been used for communicable diseases, but so far have not been used for noncommunicable diseases. Diagnostic tools have played an important role in addressing many communicable diseases, such as HIV, TB and neglected tropical diseases. Clearly more attention with regards to diagnostics for noncommunicable diseases as a key component of the health system is needed.

Cost Effectiveness of Case Detection Strategies for the Early Detection of COPD

OBJECTIVES

The value of early detection and treatment of chronic obstructive pulmonary disease (COPD) is currently unknown. We assessed the cost effectiveness of primary care-based case detection strategies for COPD.

METHODS

A previously validated discrete event simulation model of the general population of COPD patients in Canada was used to assess the cost effectiveness of 16 case detection strategies. In these strategies, eligible patients (based on age, smoking history, or symptoms) received the COPD Diagnostic Questionnaire (CDQ) or screening spirometry, at 3- or 5-year intervals, during routine visits to a primary care physician. Newly diagnosed patients received treatment for smoking cessation and guideline-based inhaler pharmacotherapy. Analyses were conducted over a 20-year time horizon from the healthcare payer perspective. Costs are in 2019 Canadian dollars ($). Key treatment parameters were varied in one-way sensitivity analysis.

RESULTS

Compared to no case detection, all 16 case detection scenarios had an incremental cost-effectiveness ratio (ICER) below $50,000/QALY gained. In the most efficient scenario, all patients aged ≥ 40 years received the CDQ at 3-year intervals. This scenario was associated with an incremental cost of $287 and incremental effectiveness of 0.015 QALYs per eligible patient over the 20-year time horizon, resulting in an ICER of $19,632/QALY compared to no case detection. Results were most sensitive to the impact of treatment on the symptoms of newly diagnosed patients.

CONCLUSIONS

Primary care-based case detection programs for COPD are likely to be cost effective if there is adherence to best-practice recommendations for treatment, which can alleviate symptoms in newly diagnosed patients.

Ambient air quality and the risk for Chronic Obstructive Pulmonary Disease among Metro Manila Development Authority traffic enforcers in Metro Manila: An exploratory study

Background

Air pollution and poor ambient air quality are significantly related to multiple health risks. One associated disease is chronic obstructive pulmonary disease (COPD), a preventable disease with several contributing factors and one of the leading causes of morbidity/mortality locally and globally. A potentially high-risk population are traffic enforcers who are constantly exposed to air pollution. In the Philippines, the MMDA has the widest coverage in traffic management. The study determined the risk of COPD among Metro Manila Development Authority (MMDA) traffic enforcers in relation to ambient air quality level, as well as identified other factors that increase the risk of developing COPD.

Methods

Fifty-two MMDA traffic enforcers deployed in PM_2.5 air quality sensor areas in Metro Manila from 2016 to 2018 were recruited through stratified sampling. The International Primary Airways Guidelines (IPAG) questionnaire was utilized to measure risk of COPD. Respiratory health and working history were obtained through questionnaires. Department of environment and natural resources provided PM_2.5 ambient air quality data which aided in the construction of the Exposure-Month Index. Ordinal logistic regression was used to examine the association of PM_2.5 together with the relevant factors and the risk of COPD.

Results

We found statistically significant associations between PM_2.5 and COPD among high risk category [odds risk (OR): 1.24, 95% confidence interval (CI): 1.07-1.44]. Age (Moderate, OR: 1.16, 95% CI: 0.98-1.38 and High, OR: 10.06, 95% CI: 4.02-25.17) and chest pain (Moderate, OR: 68.65, 95% CI: 1.71-2.75 × 10³) were potential risk factors, whereas body mass index (BMI) (OR: 0.05, 95% CI: 0.01-0.53) exhibited protective effect.

Conclusions

Exposure to PM_2.5 was associated with an increased risk of COPD among high-risk category MMDA traffic enforcers. Age and chest pain were potential risk factors to risk of COPD, whereas BMI exhibited a potential protective effect. Results of this study can be used for clinical management of high-risk populations, such that of MMDA traffic enforcers.

Protocol Summary of the COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE) Validation in Primary Care Study

Chronic obstructive pulmonary disease (COPD) often remains undiagnosed and untreated. To date, COPD screening/case finding has not been designed to identify clinically significant COPD, disease ready for therapies beyond smoking cessation. Herein, we describe the ongoing prospective, pragmatic cluster-randomized controlled trial to assess specificity and sensitivity of the COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE) tool consisting of 5 questions and peak expiratory flow. The tool is designed to identify clinically significant COPD (forced expiratory volume in 1 second [FEV₁] to forced vital capacity [FVC] ratio <.70 plus FEV₁% predicted <60% or increased risk for exacerbation) and the trial will explore the impact of CAPTURE-based screening on COPD diagnosis and treatment rates in primary care patients. Of a total planned enrollment of 5000 English- or Spanish-speaking patients 45 to 80 years of age without a prior COPD diagnosis from 100 primary care practices, a total of 68 practices and 3064 patients have been enrolled in the study. Practices are centrally randomized to either usual care or clinician receipt of patient-level CAPTURE results. All clinicians receive basic COPD education with those in intervention practices also receiving CAPTURE interpretation education. In a single visit, patient participants complete a CAPTURE screening, pre- and post-bronchodilator spirometry and baseline demographic and health questionnaires to validate CAPTURE sensitivity, specificity, and predictive value of identifying undiagnosed, clinically significant COPD. One-year follow-up chart reviews and participant surveys assess the impact of sharing versus not sharing CAPTURE results with clinicians on clinical outcomes including level of respiratory symptoms and events and clinicians' initiation of recommendation-concordant COPD care. This is one of the first U.S. studies to validate and assess impact of a simple COPD screening tool in primary care.

Study to evaluate the effectiveness and cost-effectiveness of different screening strategies for identifying undiagnosed COPD among residents (≥40 years) in four cities in China: protocol for a multicentre cross-sectional study on behalf of the Breathe Well group

INTRODUCTION

The latest chronic obstructive pulmonary disease (COPD) epidemiology survey in China estimated that there were 99 million potential COPD patients in the country, the majority of whom are undiagnosed. Screening for COPD in primary care settings is of vital importance for China, but it is not known which strategy would be the most suitable for adoption in primary care. Studies have been conducted to test the accuracy of questionnaires, expiratory peak flow meters and microspirometers to screen for COPD, but no study has directly evaluated and compared the effectiveness and cost-effectiveness of these methods in the Chinese setting.

METHODS AND ANALYSIS

We present the protocol for a multicentre cross-sectional study, to be conducted in eight community hospitals from four cities among Chinese adults aged 40 years or older to investigate the effectiveness and cost-effectiveness of different case-finding methods for COPD, and determine the test performance of individual and combinations of screening tests and strategies in comparison with quality diagnostic spirometry. Index tests are screening questionnaires (COPD Diagnostic Questionnaire (CDQ), COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk Questionnaire (CAPTURE), symptom-based questionnaire, COPD Screening Questionnaire (COPD-SQ)), microspirometer and peak flow. Each participant will complete all of these tests in one assessment. The primary analysis will compare the performance of a screening questionnaire with a handheld device. Secondary analyses will include the comparative performance of each index test, as well as a comparison of strategies where we use a screening questionnaire and a handheld device. Approximately 2000 participants will be recruited over 9 to 12 months.

ETHICS AND DISSEMINATION

The study has been approved by Peking University Hospital and University of Birmingham. All study participants will provide written informed consent. Study results will be published in appropriate journal and presented at national and international conferences, as well as relevant social media and various community/stakeholder engagement activities.

TRIAL REGISTRATION NUMBER

ISRCTN13357135.

Diagnosing Chronic Obstructive Airway Disease on a Smartphone Using Patient-Reported Symptoms and Cough Analysis: Diagnostic Accuracy Study

Background

Rapid and accurate diagnosis of chronic obstructive pulmonary disease (COPD) is problematic in acute care settings, particularly in the presence of infective comorbidities.

Objective

The aim of this study was to develop a rapid smartphone-based algorithm for the detection of COPD in the presence or absence of acute respiratory infection and evaluate diagnostic accuracy on an independent validation set.

Methods

Participants aged 40 to 75 years with or without symptoms of respiratory disease who had no chronic respiratory condition apart from COPD, chronic bronchitis, or emphysema were recruited into the study. The algorithm analyzed 5 cough sounds and 4 patient-reported clinical symptoms, providing a diagnosis in less than 1 minute. Clinical diagnoses were determined by a specialist physician using all available case notes, including spirometry where available.

Results

The algorithm demonstrated high positive percent agreement (PPA) and negative percent agreement (NPA) with clinical diagnosis for COPD in the total cohort (N=252; PPA=93.8%, NPA=77.0%, area under the curve [AUC]=0.95), in participants with pneumonia or infective exacerbations of COPD (n=117; PPA=86.7%, NPA=80.5%, AUC=0.93), and in participants without an infective comorbidity (n=135; PPA=100.0%, NPA=74.0%, AUC=0.97). In those who had their COPD confirmed by spirometry (n=229), PPA was 100.0% and NPA was 77.0%, with an AUC of 0.97.

Conclusions

The algorithm demonstrated high agreement with clinical diagnosis and rapidly detected COPD in participants presenting with or without other infective lung illnesses. The algorithm can be installed on a smartphone to provide bedside diagnosis of COPD in acute care settings, inform treatment regimens, and identify those at increased risk of mortality due to seasonal or other respiratory ailments.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12618001521213; http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375939

Impact of COPD case finding on clinical care: a prospective analysis of the TargetCOPD trial

OBJECTIVES

To investigate the impact of chronic obstructive pulmonary disease (COPD) case finding on clinical care.

DESIGN

We conducted a prospective observational analysis of data from a pragmatic cluster randomised controlled trial in primary care in the West Midlands, UK (TargetCOPD). This compared alternative methods of COPD case finding against usual care. Data were extracted from electronic healthcare records and self-reported questionnaires for a subset of patients with newly diagnosed COPD.

SETTING

50 general practices that participated in the TargetCOPD trial.

PARTICIPANTS

Patients aged 40-79 years newly identified with COPD by targeted case finding or by usual care, from 10 August 2012 to 22 June 2014.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was addition to a COPD register by the end of the trial. The secondary outcome was a clinical care score, derived from the sum of clinical assessments and relevant interventions. Associations between participant characteristics and the primary and secondary outcomes were assessed using multilevel regression.

RESULTS

857 patients identified with COPD by case finding and 764 by usual care were included. Only 21.2% of case-found patients had been added to a COPD register, compared with 92.7% of those diagnosed by usual care. The odds of being added were greater in smokers (adjusted OR 8.68, 95% CI 2.53 to 29.8), and in those with lower percentage of predicted forced expiratory volume in 1 s (adjusted OR 0.96 per percentage rise, 95% CI 0.95 to 0.98). Patients who had been added to a COPD register had a significantly higher clinical care score (mean difference 5.06, 95% CI 4.36 to 5.75).

CONCLUSIONS

Only one in five case-found patients had been registered with COPD. Patients added to a COPD register received significantly higher levels of appropriate clinical care.

TRIAL REGISTRATION NUMBER

ISRCTN14930255; Post-results.

Accuracy of Vitalograph lung monitor as a screening test for COPD in primary care

Microspirometry may be useful as the second stage of a screening pathway among patients reporting respiratory symptoms. We assessed sensitivity and specificity of the Vitalograph® lung monitor compared with post-bronchodilator confirmatory spirometry (ndd Easy on-PC) among primary care chronic obstructive pulmonary disease (COPD) patients within the Birmingham COPD cohort. We report a case-control analysis within 71 general practices in the UK. Eligible patients were aged ≥40 years who were either on a clinical COPD register or reported chronic respiratory symptoms on a questionnaire. Participants performed pre- and post-bronchodilator microspirometry, prior to confirmatory spirometry. Out of the 544 participants, COPD was confirmed in 337 according to post-bronchodilator confirmatory spirometry. Pre-bronchodilator, using the LLN as a cut-point, the lung monitor had a sensitivity of 50.5% (95% CI 45.0%, 55.9%) and a specificity of 99.0% (95% CI 96.6%, 99.9%) in our sample. Using a fixed ratio of FEV1/FEV6 < 0.7 to define obstruction in the lung monitor, sensitivity increased (58.8%; 95% CI 53.0, 63.8) while specificity was virtually identical (98.6%; 95% CI 95.8, 99.7). Within our sample, the optimal cut-point for the lung monitor was FEV1/FEV6 < 0.78, with sensitivity of 82.8% (95% CI 78.3%, 86.7%) and specificity of 85.0% (95% CI 79.4%, 89.6%). Test performance of the lung monitor was unaffected by bronchodilation. The lung monitor could be used in primary care without a bronchodilator using a simple ratio of FEV1/FEV6 as part of a screening pathway for COPD among patients reporting respiratory symptoms.

Improving Detection of Early Chronic Obstructive Pulmonary Disease

Despite being a major cause of morbidity and mortality, chronic obstructive pulmonary disease (COPD) is frequently undiagnosed. Yet the burden of disease among the undiagnosed is significant, as these individuals experience symptoms, exacerbations, and excess mortality compared to those without COPD. The U.S. Preventive Services Task Force recommends against routine screening of asymptomatic individuals with spirometry. Hence, case-finding approaches are needed. A recently developed instrument, the five-item COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk questionnaire plus peak expiratory flow, demonstrates good sensitivity and specificity for distinguishing cases from control subjects and is being studied prospectively in primary care settings to determine its impact on patient outcomes. However, finding the undiagnosed is only half the battle. Mounting evidence suggests significant COPD-like respiratory burden among individuals without airflow obstruction. Many experience dyspnea, mucus production, and exacerbation events and have emphysema and airway abnormalities on computed tomographic (CT) imaging of the chest. However, it is still unclear how to best treat these individuals and which individuals go on to develop spirometric obstruction. These challenges underline the importance of defining what constitutes "early disease." A recently proposed definition characterizes early COPD as either: 1) airflow limitation, 2) compatible CT imaging abnormalities, or 3) accelerated forced expiratory volume in 1 second decline in persons younger than 50 years and with greater than a 10 pack-year smoking history. Although it is recognized that this definition does not encompass all individuals who will develop COPD, it is an attempt to identify a group of individuals with most rapid decline to better understand mechanisms of disease development and where disease-modifying interventions are most likely to be successful. Ultimately, leveraging tools such as chest CT imaging, the electronic medical record, and machine learning algorithms may aid in the identification of such individuals.

Healthcare system encounters before COPD diagnosis: a registry-based longitudinal cohort study

BACKGROUND

There is high interest in strategies for improving early detection of chronic obstructive pulmonary disease (COPD). These strategies often rely on opportunistic encounters between patients with undiagnosed COPD and the healthcare system; however, the frequency of these encounters is currently unknown.

METHODS

We used administrative health data for the province of British Columbia, Canada, from 1996 to 2015. We identified patients with COPD using a validated case definition, and assessed their visits to pharmacists, primary care and specialist physicians in the 5 years prior to the initial diagnosis of COPD. We used generalised linear models to compare the rate of outpatient visits between COPD and non-COPD comparator subjects matched on age, sex and socioeconomic status.

RESULTS

We assessed 112 635 COPD and non-COPD pairs (mean 68.6 years, 51.0% male). Patients with COPD interacted with pharmacists most frequently in the 5 years before diagnosis (mean 14.09, IQR 4-17 visits/year), followed by primary care (10.29, IQR 4-13 visits/year) and specialist (8.11, IQR 2-11 visits/year) physicians. In the 2 years prior to diagnosis, 72.1% of patients with COPD had a respiratory-related primary care visit that did not result in a COPD diagnosis. Compared with non-COPD subjects, patients with COPD had higher rates of primary care (rate ratio (RR) 1.40, 95% CI 1.39 to 1.41), specialist (RR 1.35, 95% CI 1.34 to 1.37) and pharmacist (RR 1.62, 95% CI 1.60 to 1.63) encounters.

CONCLUSIONS

Patients with COPD used higher rates of outpatient services before diagnosis than non-COPD subjects. Case detection technologies implemented in pharmacy or primary care settings have opportunities to diagnose COPD earlier.

Spirometric indices of early airflow impairment in individuals at risk of developing COPD: Spirometry beyond FEV1/FVC

Spirometry is the current gold standard for diagnosing and monitoring the progression of Chronic Obstructive Pulmonary Disease (COPD). However, many current and former smokers who do not meet established spirometric criteria for the diagnosis of this disease have symptoms and clinical courses similar to those with diagnosed COPD. Large longitudinal observational studies following individuals at risk of developing COPD offer us additional insight into spirometric patterns of disease development and progression. Analysis of forced expiratory maneuver changes over time may allow us to better understand early changes predictive of progressive disease. This review discusses the theoretical ability of spirometry to capture fine pathophysiologic changes in early airway disease, highlights the shortcomings of current diagnostic criteria, and reviews existing evidence for spirometric measures which may be used to better detect early airflow impairment.

Handheld flow meter improves COPD detectability regardless of using a conventional questionnaire: A split-sample validation study

BACKGROUND AND OBJECTIVE

Improved detectability of chronic obstructive pulmonary disease (COPD) using a handheld flow meter (HFM) with symptom-based questionnaires has not been sufficiently evaluated. This study aimed to identify the benefit of using an HFM in COPD screening.

METHODS

A total of 2008 participants, who were ≥ 40 years of age, from Isumi City, Japan, were recruited. We developed two novel point systems for detecting COPD, one incorporated score of HFM alone (sHFM) and the other incorporated the score of International Primary Care Airway Group questionnaire (IPAG) and HFM (sIPAG + HFM). Validation using random sample allocation (split-sample validation) was carried out to assess the predictive performance of these models.

RESULTS

Participants were assigned to a data set for model creation (n = 1007) or a data set for model assessment (n = 1001) to perform split-sample validation. Decision curve analysis showed that the net benefits of sHFM and sIPAG + HFM were higher than that of the IPAG score (sIPAG) and specificity of the former two were also significantly higher than that of sIPAG. However, the curves of sHFM and sIPAG + HFM were crossing and practically the same with no significant difference in sensitivity and specificity.

CONCLUSION

This study confirms that HFM is significantly advantageous in detecting COPD despite the use of a conventional questionnaire.

[The GLORI-COPD score: detection of COPD patients at risk of complications]

DEVELOPMENT OF THE GLORI-COPD SCORE

GLObal RIsk of severe outcomes in COPD patients.

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a commonly under-diagnosed disease. This study aimed to develop a screening tool for COPD patients with a high risk of complications, taking into account COPD severity and associated co-morbidity.

METHODS

Two Delphi rounds were conducted to select the items for a preliminary score. Subsequently, this score was submitted to patients with a possible diagnosis of COPD attending for pulmonary function tests in hospital and primary care. Items associated with a diagnosis of COPD and its severity were examined with multivariate logistic regressions. Associated items in our analyses and in the literature were integrated into the score. The score was developed with a factorial analysis and optimized according to ROC curves.

RESULTS

Fifteen items were selected with the Delphi method, of which six were retained after logistic regression. They were submitted to 64 patients (mean age: 59+/-13.6 years). Factors associated with COPD were smoking ≥10 pack-years and a history of acute exacerbations. Low levels of activity and coughing up sputum were associated with COPD severity. Age ≥40 years and co-morbidities were added to the score. According to the factorial analysis, a two-stage score was developed assessing first the diagnosis of COPD and then the risk of severe outcomes. It showed a sensitivity of 71 %, a specificity of 77 %. The positive and negative predictive value were respectively 28 % and 96 %.

CONCLUSION

The score was an acceptable screening tool to identify COPD patients with high risk of complications. Nevertheless, validation needs be performed in a larger population to allow its use in primary care.

Hidden morbidity: The results of a collaborative community chronic obstructive pulmonary disease screening initiative

Chronic obstructive pulmonary disease (COPD) often goes unrecognised resulting in people living with the disease without a diagnosis. We investigated the characteristics, symptom burden and flow of participants in a community COPD screening initiative. Screening was undertaken during four events over 2-weeks. Participants completed symptom questionnaires and FEV-1/FEV-6 measurement. Patients with FEV-1 <80% predicted or FEV-1 ≥ 80% predicted and FEV-1/FEV-6 <0.72 were considered 'screen-positive' and invited to attend a 1-stop diagnostic clinic. Two hundred and fifty-seven individuals participated (mean ± SD age 58 ± 16, 24% current smokers). Seventy-seven were screen-positive with 27 ultimately attending a 1-stop clinic and 18 having confirmed COPD. The CAT score of participants with COPD was 19.3 ± 11.4. Two-thirds had moderate airflow obstruction on spirometry. The diagnosis rate in this screening initiative was comparable to trials of systematic case finding. Further research is required to explore the broader clinical impact of COPD screening.

Adult Asthma Scores-Development and Validation of Multivariable Scores to Identify Asthma in Surveys

BACKGROUND

One of the questions in epidemiology is the identification of adult asthma in studies.

OBJECTIVE

To develop and validate multivariable scores for adult asthma identification in epidemiological studies and to explore cutoffs to rule in/rule out asthma, compared with asthma diagnosed by a physician after clinical examination and diagnostic tests, blinded to the self-administered questions.

METHODS

We analyzed data (n = 711 adults) from a nationwide population-based study. The predictors were self-administered questions identified in a literature review (the Adult Asthma Epidemiological Score [A2 score]) and from the Global Allergy and Asthma Network of Excellence (GA2LEN) questionnaire (the GA2LEN Asthma Epidemiological Score [GA2LEN score]). Scores were developed using exploratory factor analysis. Internal consistency, discriminative power, and diagnostic accuracy were assessed.

RESULTS

The A2 score comprises 8 questions (including "Did a physician confirm you had asthma?") and the GA2LEN score comprises 6 questions (including "Have you ever had asthma?"). Both had high Cronbach α (0.89 and 0.85, respectively, for the A2 score and the GA2LEN score) and good area under the receiver-operating characteristic curve (90.4% and 89.0%). The scoring is the sum of positive answers. Asthma is present (rule in) for scores of 4 or more (specificity, 99.2%; PPV, 93.3% and 91.7%; accuracy, 89.4% and 87.4%, respectively, for the A2 score and the GA2LEN score). Asthma is excluded (rule out) for A2 scores of 0 to 1 and a GA2LEN score of 0 (sensitivity, 93.1%; NPV, 98.2% and 98.0%; accuracy 89.4% and 82.8%, respectively, for the A2 score and the GA2LEN score).

CONCLUSIONS

These practical scores can be used to rule in/rule out asthma in epidemiological studies and clinical screening/triage settings. They may help physicians in primary care or other specialties to screen patients with asthma using a simple score with a high level of discrimination and to identify the best candidates to be referred for a diagnostic workup. Moreover, their use may contribute to reducing the inconsistencies of operational definitions of asthma across studies and surveys.

[Spotting the GLObalRIsk of severe outcomes in undiagnosed COPD patients (GLORI-COPD)]

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a severe chronic disease and its prevalence is increasing. Nevertheless, mortality linked to moderate and mild COPD without comorbidities is low. The aim of the study is to create and validate a questionnaire in primary care to spot patients with undiagnosed COPD who are at high risk of severe complications considering the severity of their COPD and their comorbidities.

METHODS

The development of the questionnaire has three steps. The first is the selection of the items which can be included in the questionnaire with a two-round Delphi method. The second step is a cross-sectional study to assess the link between spirometry and the selected items in the first step. The last step is the validation of the questionnaire in a prospective study in primary care.

EXPECTED RESULTS

Identifying undiagnosed COPD patients with a high global risk of complications in primary care will help to establish which patients have to be diagnosed as a priority. This is particularly useful in general practice as the patient is considered globally and not just on the basis of respiratory criteria. It should allow better selection of patients who need specialised follow up.

Early Detection of Chronic Obstructive Pulmonary Disease in Primary Care

Objective To evaluate the effectiveness of an early detection program for chronic obstructive pulmonary disease (COPD) in a primary care setting in Japan. Methods Participants of ≥40 years of age who regularly visited a general practitioner's clinic due to chronic disease were asked to complete a COPD screening questionnaire (COPD Population Screener; COPD-PS) and undergo simplified spirometry using a handheld spirometric device. Patients who showed possible COPD were referred to a respiratory specialist and underwent a detailed examination that included spirometry and chest radiography. Results A total of 111 patients with possible COPD were referred for close examination. Among these patients, 27 patients were newly diagnosed with COPD. The patients with COPD were older, had lower BMI values, and had a longer smoking history in comparison to non-COPD patients. COPD patients also had more comorbid conditions. A diagnosis of COPD was significantly associated with a high COPD-PS score (p<0.001) and the detection of possible airflow limitation evaluated by the handheld spirometric device (p<0.01). An ROC curve analysis demonstrated that 5 points was the best COPD-PS cut-off value for the diagnosis of COPD. The combination of both tools showed 40.7% of sensitivity and 96.4% of specificity. Conclusion The use of the COPD-PS plus a handheld spirometric device could facilitate the early detection of undiagnosed COPD in primary care.

Multicenter study of the COPD-6 screening device: feasible for early detection of chronic obstructive pulmonary disease in primary care?

Background and aim

Early detection of COPD may reduce the future burden of the disease. We aimed to investigate whether prescreening with a COPD-6 screening device (measuring FEV₁ and FEV₆) facilitates early detection of COPD in primary care.

Methods

In primary care, individuals at high risk of COPD (ie, age ≥35 years, relevant exposure, and at least one respiratory symptom) and no previous diagnosis of obstructive lung disease were examined with a COPD-6 screening device. In prioritized order, the criteria for proceeding to confirmatory spirometry were FEV₁/FEV₆ <0.7, FEV₁ <80%pred, or clinical suspicion of COPD regardless of test result (medical doctor’s [MD] decision). Based on spirometry, including bronchodilator (BD) reversibility test, individuals were classified as COPD (post-BD FEV₁/FVC <0.70), asthma (ΔFEV₁ ≥0.50 L), or no obstructive lung disease.

Results

A total of 2,990 subjects (54% men, mean age 59 years, and mean 28 pack-years) were enrolled, of whom 949 (32%) proceeded from COPD-6 screening to confirmative spirometry based on the following criteria: 510 (54%) FEV₁/FEV₆ <0.70, 382 (40%) FEV₁ <80%pred, and 57 (6%) MD decision. Following confirmative spirometry, the 949 individuals were diagnosed as having COPD (51%), asthma (3%), and no obstructive lung disease (45%). COPD was diagnosed in 487 (16%) of the enrolled subjects in whom confirmative spirometry was performed in 69% based on FEV₁/FEV₆ <0.7 and in 29% based on FEV₁ ≤80%pred.

Conclusion

Prescreening with the COPD-6 device showed acceptable specificity for the selection of subjects for diagnostic spirometry and is likely to be a useful alternative to current practice in primary care.

A New Approach for Identifying Patients with Undiagnosed Chronic Obstructive Pulmonary Disease

RATIONALE

Chronic obstructive pulmonary disease (COPD) is often unrecognized and untreated.

OBJECTIVES

To develop a method for identifying undiagnosed COPD requiring treatment with currently available therapies (FEV₁ <60% predicted and/or exacerbation risk).

METHODS

We conducted a multisite, cross-sectional, case-control study in U.S. pulmonary and primary care clinics that recruited subjects from primary care settings. Cases were patients with COPD and at least one exacerbation in the past year or FEV₁ less than 60% of predicted without exacerbation in the past year. Control subjects were persons with no COPD or with mild COPD (FEV₁ ≥60% predicted, no exacerbation in the past year). In random forests analyses, we identified the smallest set of questions plus peak expiratory flow (PEF) with optimal sensitivity (SN) and specificity (SP).

MEASUREMENTS AND MAIN RESULTS

PEF and spirometry were recorded in 186 cases and 160 control subjects. The mean (SD) age of the sample population was 62.7 (10.1) years; 55% were female; 86% were white; and 16% had never smoked. The mean FEV₁ percent predicted for cases was 42.5% (14.2%); for control subjects, it was 82.5% (15.7%). A five-item questionnaire, CAPTURE (COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk), was used to assess exposure, breathing problems, tiring easily, and acute respiratory illnesses. CAPTURE exhibited an SN of 95.7% and an SP of 44.4% for differentiating cases from all control subjects, and an SN of 95.7% and an SP of 67.8% for differentiating cases from no-COPD control subjects. The PEF (males, <350 L/min; females, <250 L/min) SN and SP were 88.0% and 77.5%, respectively, for differentiating cases from all control subjects, and they were 88.0% and 90.8%, respectively, for distinguishing cases from no-COPD control subjects. The CAPTURE plus PEF exhibited improved SN and SP for all cases versus all control subjects (89.7% and 78.1%, respectively) and for all cases versus no-COPD control subjects (89.7% and 93.1%, respectively).

CONCLUSIONS

CAPTURE with PEF can identify patients with COPD who would benefit from currently available therapy and require further diagnostic evaluation. Clinical trial registered with clinicaltrials.gov (NCT01880177).

Predicting risk of undiagnosed COPD: development and validation of the TargetCOPD score

Chronic obstructive pulmonary disease (COPD) is greatly underdiagnosed worldwide and more efficient methods of case-finding are required. We developed and externally validated a risk score to identify undiagnosed COPD using primary care records.

We conducted a retrospective cohort analysis of a pragmatic cluster randomised controlled case-finding trial in the West Midlands, UK. Participants aged 40–79 years with no prior diagnosis of COPD received a postal or opportunistic screening questionnaire. Those reporting chronic respiratory symptoms were assessed with spirometry. COPD was defined as presence of relevant symptoms with a post-bronchodilator forced expiratory volume in 1 s/forced vital capacity ratio below the lower limit of normal. A risk score was developed using logistic regression with variables available from electronic health records for 2398 participants who returned a postal questionnaire. This was externally validated among 1097 participants who returned an opportunistic questionnaire to derive the c-statistic, and the sensitivity and specificity of cut-points.

A risk score containing age, smoking status, dyspnoea, prescriptions of salbutamol and prescriptions of antibiotics discriminated between patients with and without undiagnosed COPD (c-statistic 0.74, 95% CI 0.68–0.80). A cut-point of ≥7.5% predicted risk had a sensitivity of 68.8% (95% CI 57.3–78.9%) and a specificity of 68.8% (95% CI 65.8.1–71.6%).

A novel risk score using routine data from primary care electronic health records can identify patients at high risk for undiagnosed symptomatic COPD. This score could be integrated with clinical information systems to help primary care clinicians target patients for case-finding.

How Well Does CAPTURE Translate?: An Exploratory Analysis of a COPD Case-Finding Method for Spanish-Speaking Patients

BACKGROUND

This study tested the properties of a Spanish translation of CAPTURE (COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk) with selective use of peak expiratory flow (PEF).

METHODS

This study comprised analyses of data from the Spanish-speaking cohort of the cross-sectional, case-control study used to develop CAPTURE. Translation procedures included forward and backward translation, reconciliation, and cognitive interviewing to assure linguistic and cultural equivalence, yielding CAPTURE-S. Spanish-speaking participants were recruited through one center and designated as case subjects (clinically significant COPD: FEV₁ ≤ 60% predicted and/or at risk of COPD exacerbation) or control subjects (no or mild COPD). Subjects completed a questionnaire booklet that included 44 candidate items, the COPD Assessment Test (CAT), and the modified Medical Research Council (mMRC) dyspnea question. PEF and spirometry were also performed.

RESULTS

The study included 30 participants (17 case subjects and 13 control subjects). Their mean (± SD) age was 62.6 (11.49) years, and 33% were male. CAPTURE-S scores were significantly correlated with PEF (r = -0.78), the FEV₁/FVC ratio (r = -0.74), FEV₁ (r = -0.69), FEV₁ % predicted (r = -0.69), the CAT score (r = 0.70), and the mMRC dyspnea question (r = 0.59) (P < .0001), with significantly higher scores in case subjects than in control subjects (t = 6.16; P < .0001). PEF significantly correlated with FEV₁ (r = 0.89), FEV₁ % predicted (r = 0.79), and the FEV₁/FVC ratio (r = 0.75) (P < .0001), with significantly lower PEF in case subjects than in control subjects (t = 5.08; P < .0001). CAPTURE-S score + PEF differentiated case subjects and control subjects with a sensitivity of 88.2% and a specificity of 92.3%.

CONCLUSIONS

CAPTURE-S with selective use of PEF seems to be useful for identifying Spanish-speaking patients in need of diagnostic evaluation for clinically significant COPD who may benefit from initiation of COPD treatment.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01880177; URL: www.clinicaltrials.gov.

Development and the initial validation of a new self-administered questionnaire for an early detection of health status changes in smokers at risk for chronic obstructive pulmonary disease (MARKO questionnaire)

AIM

To develop and do an initial validation of a new simple tool (self-administered questionnaire) that would be sensitive and specific enough to detect early changes in smokers leading to future development of chronic obstructive pulmonary disease (COPD).

METHODS

224 consecutive participants (50.9% women), with mean±standard deviation age of 52.3±6.7 years, 37.5±16.7 pack-years smoking history (85.8% active smokers), and no prior diagnosis of COPD were recruited. The MARKO questionnaire was self-administered twice; at the general practitioner's office and after 2-4 weeks at the tertiary care hospital. Participants were assessed for COPD by a pulmonologist after filling in a quality of life (QoL) questionnaires, history-taking, physical examination, lung function test, 6-minute walk test, and laboratory tests. They were divided into four subgroups: "healthy" smokers, symptomatic smokers, and smokers with mild and moderately severe COPD.

RESULTS

Psychometric analyses indicated that the 18-item questionnaire had a very good internal consistency (Cronbach's alpha=0.91) and test-retest reliability for a four week period (c=0.89, 95% confidence interval [CI] 0.85-0.92, Lin's concordance). A significant correlations of MARKO scores were found with two QoL questionnaires; r=0.69 (P<0.001) and r=0.81 (P<0.001). Receiver operating characteristic curve analysis showed an area under the curve of 0.753 (95% CI 0.691-0.808, <0.001), with a sensitivity of 71.83% and specificity of 64.24% to discriminate "healthy" smokers from other subgroups.

CONCLUSION

Based on psychometric analyses and high convergent validity correlation with already validated QoL questionnaires, the newly developed MARKO questionnaire was shown to be a reliable self-administered short health status assessment tool.

Early detection of COPD patients in GOLD 0 population: an observational non-interventional cohort study - MARKO study

BACKGROUND

Main risk factor for the development of chronic obstructive pulmonary disease (COPD) is smoking, although only less than 1/3 of smokers develop clinically manifest COPD. COPD's progressive nature with high disability and mortality makes it plausible to detect it as early as possible thus allowing for an early intervention. The only tool for an early diagnosis that could be used on the global scale is spirometry, even though symptoms and deprivation of health related quality of life (HRQoL) precede relevant spirometric changes. Existing HRQoL questionnaires are too complicated or not developed for an early detection of COPD. The aim of our study was to develop a new simple HRQoL tool that will allow (alone or in combination with other markers) early detection of patients with COPD.

METHODS

A multicenter prospective cohort study recruiting 500 subjects at risk for COPD (smokers/ex-smokers ≥20 pack-years, 40-65 years, both sexes, with no prior diagnosis of COPD) will be carried out in two phases: (1) cross-sectional - development and validation of a new questionnaire; and (2) prospective - follow-up of a cohort of patients at risk for COPD. Subjects were recruited by 25 GPs and assessed for COPD by dedicated pulmonologists in 7 hospital centers using a predefined protocol: HRQoL, history, physical, blood sampling, exhaled breath temperature (EBT), lung function, 6-min walk test (6MWT). Patients without COPD and those in GOLD stage 1 at initial assessment will be reassessed for disease progression by the same pulmonologist after 2 and 5 years.

DISCUSSION

This is one of the first cohort studies attempting to establish the incidence of COPD in the pre-symptomatic stage before significant end organ damage. We intend to assess the validity, predictability and discriminative power ('healthy' smokers vs. pre-symptomatic phase in newly developed COPD) of newly developed HRQoL tool alone or in combination with other markers; EBT, lung function, 6MWT, genomics, transcriptomics, proteomics). We expect that the results of this study can improve our understanding of the development of COPD, identify some new underlying pathophysiological pathways, and offer to sensitive smokers/ex-smokers new preventive and early intervention measures thus improving the management of COPD.

TRIAL REGISTRATION

Clinicaltrial.gov NCT01550679 retrospectively registered February 28, 2012.

Development and validation of the Salzburg COPD-screening questionnaire (SCSQ): a questionnaire development and validation study

Chronic obstructive pulmonary disease prevalence rates are still high. However, the majority of subjects are not diagnosed. Strategies have to be implemented to overcome the problem of under-diagnosis. Questionnaires could be used to pre-select subjects for spirometry and thereby help reducing under-diagnosis. We report a brief, simple, self-administrable and validated chronic obstructive pulmonary disease questionnaire to increase the pre-test probability for chronic obstructive pulmonary disease diagnosis in subjects undergoing confirmatory spirometry. In 2005, we completed the Austrian Burden of Obstructive Lung Disease-study in 1258 subjects aged >40 years. Post-bronchodilator spirometry was performed, and non-reversible airflow limitation defined by FEV1/FVC ratio below the lower limit of normal. Questions from the Salzburg chronic obstructive pulmonary disease screening-questionnaire were selected using a logistic regression model, and risk scores were based on regression-coefficients. A training sub-sample (n = 800) was used to create the score, and a test sub-sample (n = 458) was used to test it. In 2008, an external validation study was done, using the same protocol in 775 patients from primary care. The Salzburg chronic obstructive pulmonary disease screening questionnaire was composed of items related to "breathing problems", "wheeze", "cough", "limitation of physical activity", and "smoking". At the >=2 points cut-off of the Salzburg chronic obstructive pulmonary disease screening questionnaire, sensitivity was 69.1% [95%CI: 56.6%; 79.5%], specificity 60.0% [95%CI: 54.9%; 64.9%], the positive predictive value 23.2% [95%CI: 17.7%; 29.7%] and the negative predictive value 91.8% [95%CI: 87.5%; 95.7%] to detect post bronchodilator airflow limitation. The external validation study in primary care confirmed these findings. The Salzburg chronic obstructive pulmonary disease screening questionnaire was derived from the highly standardized Burden of Obstructive Lung Disease study. This validated and easy to use questionnaire can help to increase the efficiency of chronic obstructive pulmonary disease case-finding.

CHRONIC OBSTRUCTIVE PULMONARY DISEASE

QUESTIONNAIRE FOR PRE-SCREENING POTENTIAL SUFFERERS: Scientists in Austria have developed a brief, simple questionnaire to identify patients likely to have early-stage chronic lung disease. Chronic obstructive pulmonary disease (COPD) is notoriously difficult to diagnose, and the condition often causes irreversible lung damage before it is identified. Finding a simple, cost-effective method of pre-screening patients with suspected early-stage COPD could potentially improve treatment responses and limit the burden of extensive lung function ('spirometry') tests on health services. Gertraud Weiss at Paracelsus Medical University, Austria, and co-workers have developed and validated an easy-to-use, self-administered questionnaire that could prove effective for pre-screening patients. The team trialed the five-point Salzburg COPD-screening questionnaire on 1258 patients. Patients scoring 2 points or above on the questionnaire underwent spirometry tests. The questionnaire seems to provide a sensitive and cost-effective way of pre-selecting patients for spirometry referral.

Which is the Best Screening Strategy for COPD among Smokers in Primary Care?

We developed a questionnaire to detect cases of chronic obstructive pulmonary disease (COPD) and compared its reliability with other strategies. In order to develop the new questionnaire (COPD screening questionnaire from Terrassa [EGARPOC]) we used data from an epidemiological study on the prevalence of COPD in smokers and calculated the odds ratio for each variable showing significance for the diagnosis of COPD on regression analysis. For comparison among questionnaires and the portable spirometer COPD-6, a cross-sectional multicenter study was performed. The study included 407 smokers or ex-smokers over the age of 40 years with no known diagnosis of COPD, who completed the different questionnaires (EGARPOC, Respiratory Health Screening Questionnaire, COPD-population screener and 2 questions) and underwent spirometry with the COPD-6. We determined the sensitivity, specificity, positive and negative predictive values (S, Sp, PPV and NPV, respectively) and the area under the receiver operating characteristic ROC curve (AUC ROC) of all the questionnaires and the different COPD-6 cut-offs. The prevalence of COPD was 26.3%. The EGARPOC questionnaire showed an S of 81.8%, an Sp of 70.6%, and an NPV of 91.8%; 73.3% of individuals were correctly classified, and the AUC ROC was 0.841. On comparing the questionnaires by the Chi-square test, the 2-question questionnaire showed the worst discrimination; while with an optimal cut-off of forced expiratory volume in one 1 second (FEV₁)/FEV₆ of 0.78, the COPD-6 was significantly better than the questionnaires in the detection of COPD. Using a cut-off of FEV₁/FEV₆ of 0.78 the COPD-6 was found to be the best screening tool for COPD in primary care compared to the questionnaires tested, which did not show differences among them.

Defining and targeting health disparities in chronic obstructive pulmonary disease

The global burden of chronic obstructive pulmonary disease (COPD) continues to grow in part due to better outcomes in other major diseases and in part because a substantial portion of the worldwide population continues to be exposed to inhalant toxins. However, a disproportionate burden of COPD occurs in people of low socioeconomic status (SES) due to differences in health behaviors, sociopolitical factors, and social and structural environmental exposures. Tobacco use, occupations with exposure to inhalant toxins, and indoor biomass fuel (BF) exposure are more common in low SES populations. Not only does SES affect the risk of developing COPD and etiologies, it is also associated with worsened COPD health outcomes. Effective interventions in these people are needed to decrease these disparities. Efforts that may help lessen these health inequities in low SES include 1) better surveillance targeting diagnosed and undiagnosed COPD in disadvantaged people, 2) educating the public and those involved in health care provision about the disease, 3) improving access to cost-effective and affordable health care, and 4) markedly increasing the efforts to prevent disease through smoking cessation, minimizing use and exposure to BF, and decreasing occupational exposures. COPD is considered to be one the most preventable major causes of death from a chronic disease in the world; therefore, effective interventions could have a major impact on reducing the global burden of the disease, especially in socioeconomically disadvantaged populations.

Diagnosing COPD: advances in training and practice - a systematic review

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung syndrome, caused by long-term inhalation of noxious gases and particles, which leads to gradual airflow limitation. All health care professionals who care for COPD patients should have full access to high-quality spirometry testing, as postbronchodilator spirometry constitutes the principal method of COPD diagnosis. One out of four smokers 45 years or older presenting respiratory symptoms in primary care, have non-fully reversible airflow limitation compatible with COPD and are mostly without a known diagnosis. Approximately 50.0%-98.3% of patients are undiagnosed worldwide. The majority of undiagnosed COPD patients are isolated at home, are in nursing or senior-assisted living facilities, or are present in oncology and cardiology clinics as patients with lung cancers and coronary artery disease. At this time, the prevalence and mortality of COPD subjects is increasing, rapidly among women who are more susceptible to risk factors. Since effective management strategies are currently available for all phenotypes of COPD, correctly performed and well-interpreted postbronchodilator spirometry is still an essential component of all approaches used. Simple educational training can substantially improve physicians' knowledge relating to COPD diagnosis. Similarly, a physician inhaler education program can improve attitudes toward inhaler teaching and facilitate its implementation in routine clinical practices. Spirometry combined with inhaled technique education improves the ability of predominantly nonrespiratory physicians to correctly diagnose COPD, to adequately assess its severity, and to increase the percentage of correct COPD treatment used in a real-life setting.