Case-finding options for COPD: results from the Burden of Obstructive Lung Disease study

The Role of Pulmonary Function Testing in the Diagnosis and Management of COPD

Pulmonary function testing (PFT) has a long and rich history in the definition, diagnosis, and management of COPD. For decades, spirometry has been regarded as the standard for diagnosing COPD; however, numerous studies have shown that COPD symptoms, pathology, and associated poor outcomes can occur, despite normal spirometry. Diffusing capacity and imaging studies have called into question the need for spirometry to put the "O" (obstruction) in COPD. The role of exercise testing and the ability of PFTs to phenotype COPD are reviewed. Although PFTs play an important role in diagnosis, treatment decisions are primarily determined by symptom intensity and exacerbation history. Although a seminal study positioned FEV1 as the primary predictor of survival, numerous studies have shown that tests other than spirometry are superior predictors of mortality. In years past, using spirometry to screen for COPD was promulgated; however, this only seems appropriate for individuals who are symptomatic and at risk for developing COPD.

Screening for impaired pulmonary function using peak expiratory flow: Performance of different interpretation strategies

BACKGROUND

Spirometry is the gold standard for diagnosis of impaired pulmonary function, but is often unavailable in resource-constrained settings. Some authors have suggested using peak expiratory flow (PEF) to screen for impaired pulmonary function when spirometry is unavailable, but with no consensus on how to define abnormally low PEF. Strategies have included cutoffs based on absolute value of PEF, PEF in percent predicted, PEF Z-score, PEF × height^-2, and gender-specific cutoffs of absolute PEF. The objective of this paper is to determine the PEF interpretation strategy with the highest predictive ability for low pulmonary function, with spirometry as the gold standard.

METHODS

We analyzed data on individuals aged 40-79 years in the United States National Health and Nutrition Examination Survey 2007-2012. 6,144 individuals fulfilled inclusion criteria for the main analysis. For each PEF interpretation strategy, we calculated the area under the receiver operating curve (AUC) for the detection of low pulmonary function (defined by FEV₁ Z-score < -1.645, < -2, < -2.5 or < -3).

RESULTS

The AUC was substantially and statistically significantly higher for PEF in percent predicted and PEF Z-score than for absolute value and PEF × height^-2, including after stratification by gender. There was no difference in AUC between PEF in percent predicted and PEF Z-score.

CONCLUSION

If using PEF to screen adults aged 40 years or older for impaired pulmonary function defined by low FEV₁ Z-score, basing cutoffs on PEF in percent predicted or PEF Z-score may result in improved predictive ability. As percent predicted is a mathematically simpler term than Z-score, it may be preferable to use cutoffs based on PEF in percent predicted.

Associations of Vitamin D, chronic obstructive pulmonary disease and acute exacerbations of COPD with anxiety and depression: a nested case control study

Background: Lower vitamin D levels have not only been associated with chronic obstructive pulmonary disease (COPD), exacerbations and lower lung functions, but also with anxiety and depression. We examined the associations of severity of anxiety and depression using HAM-A (Hamilton Anxiety Rating Scale) and HAM-D (Hamilton Depression Rating Scale) scores with COPD and vitamin D levels. Methods: Observational nested case control study was conducted in MUDHRA cohort. One hundred COPD subjects and 100 age- gender- matched non-COPD subjects (controls) underwent evaluation of socioeconomic status, respiratory symptoms, spirometry, severity of anxiety and depression, six minute walk test and estimation of serum vitamin D levels. Independent association of low vitamin D levels with severity of anxiety and depression was assessed by logistic regression. Results: COPD group had higher mean±SD anxiety and depression scores (HAM-A 8.0±3.5, HAM-D 8.72±4) compared to control group (HAM-A 4.51±2.2, HAM-D 4.3±2). The COPD group had 53 subjects with mild/moderate anxiety/depression whereas control group had 16 subjects with mild/moderate anxiety/depression. In COPD group, subjects with mild/moderate anxiety/depression had lower vitamin D levels compared to subjects with no/minimal anxiety/depression, while the difference in control group was not significant. In logistic regression, anxiety and depression levels had independent association with vitamin D levels, lung function variables, six-minute walk distance and presence of COPD. In COPD subgroup, anxiety and depression levels had independent association with breathlessness, GOLD FEV1 staging, CAT score, SGRQ-C Symptom score and exacerbation of COPD. Conclusions: Greater proportion of COPD subjects suffer from anxiety and depression as compared to subjects without COPD. Severity of anxiety and depression was greater in COPD subjects. Poorer lung functions, higher respiratory symptoms and lower vitamin D levels are associated with higher levels of anxiety and depression in COPD subjects.  There is an urgent need to recognise anxiety and depression in COPD patients.

Detection and staging of chronic obstructive pulmonary disease using a computed tomography-based weakly supervised deep learning approach

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is underdiagnosed globally. The present study aimed to develop weakly supervised deep learning (DL) models that utilize computed tomography (CT) image data for the automated detection and staging of spirometry-defined COPD.

METHODS

A large, highly heterogeneous dataset was established, consisting of 1393 participants retrospectively recruited from outpatient, inpatient, and physical examination center settings of four large public hospitals in China. All participants underwent both inspiratory chest CT scans and pulmonary function tests. CT images, spirometry data, demographic information, and clinical information of each participant were collected. An attention-based multi-instance learning (MIL) model for COPD detection was trained using CT scans from 837 participants. External validation of the COPD detection was performed with 620 low-dose CT (LDCT) scans acquired from the National Lung Screening Trial (NLST) cohort. A multi-channel 3D residual network was further developed to categorize GOLD stages among confirmed COPD patients.

RESULTS

The attention-based MIL model used for COPD detection achieved an area under the receiver operating characteristic curve (AUC) of 0.934 (95% CI: 0.903, 0.961) on the internal test set and 0.866 (95% CI: 0.805, 0.928) on the LDCT subset acquired from the NLST. The multi-channel 3D residual network was able to correctly grade 76.4% of COPD patients in the test set (423/553) using the GOLD scale.

CONCLUSIONS

The proposed chest CT-DL approach can automatically identify spirometry-defined COPD and categorize patients according to the GOLD scale. As such, this approach may be an effective case-finding tool for COPD diagnosis and staging.

KEY POINTS

• Chronic obstructive pulmonary disease is underdiagnosed globally, particularly in developing countries. • The proposed chest computed tomography (CT)-based deep learning (DL) approaches could accurately identify spirometry-defined COPD and categorize patients according to the GOLD scale. • The chest CT-DL approach may be an alternative case-finding tool for COPD identification and evaluation.

Discriminative Accuracy of Chronic Obstructive Pulmonary Disease Screening Instruments in 3 Low- and Middle-Income Country Settings

IMPORTANCE

Most of the global morbidity and mortality in chronic obstructive pulmonary disease (COPD) occurs in low- and middle-income countries (LMICs), with significant economic effects.

OBJECTIVE

To assess the discriminative accuracy of 3 instruments using questionnaires and peak expiratory flow (PEF) to screen for COPD in 3 LMIC settings.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional analysis of discriminative accuracy, conducted between January 2018 and March 2020 in semiurban Bhaktapur, Nepal; urban Lima, Peru; and rural Nakaseke, Uganda, using a random age- and sex-stratified sample of the population 40 years or older.

EXPOSURES

Three screening tools, the COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE; range, 0-6; high risk indicated by a score of 5 or more or score 2-5 with low PEF [<250 L/min for females and <350 L/min for males]), the COPD in LMICs Assessment questionnaire (COLA-6; range, 0-5; high risk indicated by a score of 4 or more), and the Lung Function Questionnaire (LFQ; range, 0-25; high risk indicated by a score of 18 or less) were assessed against a reference standard diagnosis of COPD using quality-assured postbronchodilator spirometry. CAPTURE and COLA-6 include a measure of PEF.

MAIN OUTCOMES AND MEASURES

The primary outcome was discriminative accuracy of the tools in identifying COPD as measured by area under receiver operating characteristic curves (AUCs) with 95% CIs. Secondary outcomes included sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

Among 10 709 adults who consented to participate in the study (mean age, 56.3 years (SD, 11.7); 50% female), 35% had ever smoked, and 30% were currently exposed to biomass smoke. The unweighted prevalence of COPD at the 3 sites was 18.2% (642/3534 participants) in Nepal, 2.7% (97/3550) in Peru, and 7.4% (264/3580) in Uganda. Among 1000 COPD cases, 49.3% had clinically important disease (Global Initiative for Chronic Obstructive Lung Disease classification B-D), 16.4% had severe or very severe airflow obstruction (forced expiratory volume in 1 second <50% predicted), and 95.3% of cases were previously undiagnosed. The AUC for the screening instruments ranged from 0.717 (95% CI, 0.677-0.774) for LFQ in Peru to 0.791 (95% CI, 0.770-0.809) for COLA-6 in Nepal. The sensitivity ranged from 34.8% (95% CI, 25.3%-45.2%) for COLA-6 in Nepal to 64.2% (95% CI, 60.3%-67.9%) for CAPTURE in Nepal. The mean time to administer the instruments was 7.6 minutes (SD 1.11), and data completeness was 99.5%.

CONCLUSIONS AND RELEVANCE

This study demonstrated that screening instruments for COPD were feasible to administer in 3 low- and middle-income settings. Further research is needed to assess instrument performance in other low- and middle-income settings and to determine whether implementation is associated with improved clinical outcomes.

Unmet need in the management of chronic obstructive pulmonary disease in the Middle East and Africa region: An expert panel consensus

Chronic obstructive pulmonary disease (COPD) has a significant impact on healthcare systems and health-related quality of life. Increased prevalence of smoking is an important factor contributing to high burden of COPD in the Middle East and Africa (MEA). Several other factors including sedentary lifestyle, urbanization, second-hand smoke, air pollution, and occupational exposure are also responsible for the upsurge of COPD in the MEA. Frequent COPD exacerbations accelerate disease progression, progressively deteriorate the lung function, and negatively affect quality of life. This consensus is based on review of the published evidence, international and regional guidelines, and insights provided by the expert committee members from the MEA region. Spirometry, though the gold standard for diagnosis, is often unavailable and/or underutilized leading to underdiagnosis of COPD in primary care settings. Low adherence to the treatment guidelines and delayed use of appropriate combination therapy including triple therapy are additional barriers in management of COPD in MEA. It is necessary to recognize COPD as a screenable condition and develop easy and simple screening tools to facilitate early diagnosis. Knowledge of the disease symptomatology at patient and physician level and adherence to the international or regional guidelines are important to create awareness about harmful effects of smoking and develop national guidelines to focus on prevention on COPD. Implementation of vaccination program and pulmonary rehabilitation are equally valuable to manage patients with COPD at local and regional level. We present recommendations made by the expert panel for improved screening, diagnosis, and management of COPD in MEA.

Challenges in the Implementation of Chronic Obstructive Pulmonary Disease Guidelines in Low- and Middle-Income Countries: An Official American Thoracic Society Workshop Report

There is a substantial burden of chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), in low- and middle-income countries (LMICs). LMICs have particular challenges in delivering cost-effective prevention, diagnosis, and management of COPD. Optimal care can be supported by effective implementation of guidelines. This American Thoracic Society workshop considered challenges to implementation of COPD guidelines in LMICs. We make 10 specific recommendations: 1) relevant organizations should provide LMIC-specific COPD management guidance; 2) patient and professional organizations must persuade policy-makers of the importance of lung function testing programs in LMICs; 3) healthcare education and training should emphasize the early-life origins of COPD; 4) urgent action is required by governments to reduce airborne exposures, including exposures to tobacco smoke and indoor and outdoor air pollution; 5) guidance for COPD in LMICs should explicitly link across Essential Medicine Lists and the World Health Organization package of essential noncommunicable disease interventions for primary health care in low-resource settings and should consider availability, affordability, sustainability, and cost-effective use of medicines; 6) the pharmaceutical industry should work to make effective COPD and tobacco-dependence medicines globally accessible and affordable; 7) implementation of locally adapted, cost-effective pulmonary rehabilitation programs should be an international priority; 8) the World Health Organization Global Action Plan for the Prevention and Control of Noncommunicable Diseases should specify how improvements in respiratory health will be achieved; 9) research funders should increase the proportion of funding allocated to COPD in LMICs; and 10) the respiratory community should leverage the skills and enthusiasm of earlier-career clinicians and researchers to improve global respiratory health.

Vitamin D deficiency is associated with chronic obstructive pulmonary disease and exacerbation of COPD

INTRODUCTION

Low Vitamin D levels have been associated with Chronic Obstructive Pulmonary Disease (COPD) and acute exacerbations.

OBJECTIVES

There is a paucity of data on Vitamin D and COPD, its severity and exacerbations in populations that are exposed to sunlight regularly with high levels of physical activity most of their lives.

METHODS

Serum levels of 25-OH-Vitamin-D were assessed in 100 COPD subjects and 100 age- and gender-matched controls from the rural community-based MUDHRA cohort in South India. Levels of <20 ng/mL were defined as Vitamin D deficiency. Smoking habits, occupation, Charlson co-morbidity index, Standard of living index(SLI), body mass index(BMI), 6-minute walking distance were examined for associations with logistic regression between controls and COPD subjects. Unconditional logistic regression was used to examine the association with exacerbation of COPD.

RESULTS

Vitamin D deficiency was observed in 64.5% (95%CI 57.7-70.8) of the subjects in spite of regular exposure to sunlight. Subjects with COPD had higher risk of Vitamin D deficiency (Adjusted OR: 5.05; 95%CI 1.4-17.8) as compared to controls. Amongst subjects with COPD, Vitamin D deficient subjects were three times more likely to have exacerbations in the previous year (Adjusted OR:3.51; 95%CI 1.27-9.67) as compared to COPD subjects without Vitamin D deficiency. Levels of Vitamin D <20.81 ng/mL and <18.45 ng/mL had the highest levels of combined sensitivity and specificity for COPD and acute exacerbation of COPD (AECOPD) respectively.

CONCLUSION

In a rural population exposed to sunlight many hours a day throughout their lives, low Vitamin D levels were associated with COPD and exacerbations of COPD.

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.

Prevalence of different comorbidities in chronic obstructive pulmonary disease among Shahrekord PERSIAN cohort study in southwest Iran

Comorbidities are common in chronic obstructive pulmonary disease (COPD) patients. This study was conducted to determine the prevalence of common comorbidities in patients with COPD compared with people without COPD. This cross-sectional, population-based study was performed on 6961 adults aged 35-70 years enrolled in the Shahrekord PERSIAN cohort study. Data (demographic and clinical characteristics, comorbidities, anthropometric and blood pressure measurements, laboratory, and spirometry tests) collection was performed according to the cohort protocol from 2015 to 2019. In the present study, 215 (3.1%) patients were diagnosed with COPD and 1753 (25.18%) ones with restrictive lung patterns. The mean age of COPD patients was 52.5 ± 9.76 years. 55.8% of patients were male, 17.7% were current smokers and 12.1% had a history of smoking or were former smokers. 5.6% of patients had no comorbidity and 94.5% had at least one comorbidity. The most common comorbidities in COPD patients were dyslipidemia (70.2%), hypertension (30.2%), metabolic syndrome (22.8%), and diabetes (16.7%). The most common comorbidities in individuals with a restrictive spirometry pattern were dyslipidemia (68.9%), metabolic syndrome (27.2%), hypertension (26.1%), depression (17.6%), and fatty liver (15.5%). The logistic regression analysis with 95% confidence interval (95%CI) of odds ratio (OR) showed that comorbidities of chronic lung diseases (OR = 2.12, 95% CI 1.30-3.44), diabetes (OR = 1.54, 95%CI 1.03-2.29), cardiovascular disease (OR = 1.52, 95%CI 1.17-2.43), and hypertension (OR = 1.4, 95%CI 1.02-1.99) were more likely to occur in COPD patients than in healthy individuals. Knowing these prevalence rates and related information provides new insights on comorbidities to reduce disease burden and develop preventive interventions and to regulate health care resources to meet the needs of patients in primary health care.

Global Initiative for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease. The 2020 GOLD Science Committee Report on COVID-19 and Chronic Obstructive Pulmonary Disease

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has raised many questions about the management of patients with chronic obstructive pulmonary disease (COPD) and whether modifications of their therapy are required. It has raised questions about recognizing and differentiating coronavirus disease (COVID-19) from COPD given the similarity of the symptoms. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) Science Committee used established methods for literature review to present an overview of the management of patients with COPD during the COVID-19 pandemic. It is unclear whether patients with COPD are at increased risk of becoming infected with SARS-CoV-2. During periods of high community prevalence of COVID-19, spirometry should only be used when it is essential for COPD diagnosis and/or to assess lung function status for interventional procedures or surgery. Patients with COPD should follow basic infection control measures, including social distancing, hand washing, and wearing a mask or face covering. Patients should remain up to date with appropriate vaccinations, particularly annual influenza vaccination. Although data are limited, inhaled corticosteroids, long-acting bronchodilators, roflumilast, or chronic macrolides should continue to be used as indicated for stable COPD management. Systemic steroids and antibiotics should be used in COPD exacerbations according to the usual indications. Differentiating symptoms of COVID-19 infection from chronic underlying symptoms or those of an acute COPD exacerbation may be challenging. If there is suspicion for COVID-19, testing for SARS-CoV-2 should be considered. Patients who developed moderate-to-severe COVID-19, including hospitalization and pneumonia, should be treated with evolving pharmacotherapeutic approaches as appropriate, including remdesivir, dexamethasone, and anticoagulation. Managing acute respiratory failure should include appropriate oxygen supplementation, prone positioning, noninvasive ventilation, and protective lung strategy in patients with COPD and severe acute respiratory distress syndrome. Patients who developed asymptomatic or mild COVID-19 should be followed with the usual COPD protocols. Patients who developed moderate or worse COVID-19 should be monitored more frequently and accurately than the usual patients with COPD, with particular attention to the need for oxygen therapy.

Addressing Reduced Laboratory-Based Pulmonary Function Testing During a Pandemic

To reduce the spread of the severe acute respiratory syndrome coronavirus 2, many pulmonary function testing (PFT) laboratories have been closed or have significantly reduced their testing capacity. Because these mitigation strategies may be necessary for the next 6 to 18 months to prevent recurrent peaks in disease prevalence, fewer objective measurements of lung function will alter the diagnosis and care of patients with chronic respiratory diseases. PFT, which includes spirometry, lung volume, and diffusion capacity measurement, is essential to the diagnosis and management of patients with asthma, COPD, and other chronic lung conditions. Both traditional and innovative alternatives to conventional testing must now be explored. These may include peak expiratory flow devices, electronic portable spirometers, portable exhaled nitric oxide measurement, airwave oscillometry devices, and novel digital health tools such as smartphone microphone spirometers and mobile health technologies along with integration of machine learning approaches. The adoption of some novel approaches may not merely replace but could improve existing management strategies and alter common diagnostic paradigms. With these options comes important technical, privacy, ethical, financial, and medicolegal barriers that must be addressed. However, the coronavirus disease 19 pandemic also presents a unique opportunity to augment conventional testing by including innovative and emerging approaches to measuring lung function remotely in patients with respiratory disease. The benefits of such an approach have the potential to enhance respiratory care and empower patient self-management well beyond the current global pandemic.

A Novel Case-Finding Instrument for Chronic Obstructive Pulmonary Disease in Low- and Middle-Income Country Settings

Background

Low- and middle-income countries (LMICs) account for >90% of deaths and illness episodes related to COPD; however, this condition is commonly underdiagnosed in these settings. Case-finding instruments for COPD may improve diagnosis and identify individuals that need treatment, but few have been validated in resource-limited settings.

Methods

We conducted a population-based cross-sectional study in Uganda to assess the diagnostic accuracy of a respiratory symptom, exposure and functional questionnaire in combination with peak expiratory flow for COPD diagnosis using post-bronchodilator FEV1/FVC z-score below the 5th percentile as the gold standard. We included locally relevant exposure questions and statistical learning techniques to identify the most important risk factors for COPD. We used 80% of the data to develop the case-finding instrument and validated it in the remaining 20%. We evaluated for calibration and discrimination using standard approaches. The final score, COLA (COPD in LMICs Assessment), included seven questions, age and pre-bronchodilator peak expiratory flow.

Results

We analyzed data from 1,173 participants (average age 47 years, 46.9% male, 4.5% with COPD) with acceptable and reproducible spirometry. The seven questions yielded a cross-validated area-under-the-curve [AUC] of 0.68 (95% CI 0.61-0.75) with higher scores conferring greater odds of COPD. The inclusion of peak expiratory flow and age improved prediction in a validation sample (AUC=0.83, 95% CI 0.78-0.88) with a positive predictive value of 50% and a negative predictive value of 96%. The final instrument (COLA) included seven questions, age and pre-bronchodilator peak expiratory flow.

Conclusion

COLA predicted COPD in urban and rural settings in Uganda has high calibration and discrimination, and could serve as a simple, low-cost screening tool in resource-limited settings.

COPDCompEx: A novel composite endpoint for COPD exacerbations to enable faster clinical development

BACKGROUND

Frequency of moderate and severe chronic obstructive pulmonary disease exacerbations is an important endpoint in clinical trials, but makes them large and lengthy when powered to evaluate it. We aimed to develop a composite endpoint (COPDCompEx) that could predict treatment effect on exacerbations, enabling the design of shorter early phase clinical trials requiring fewer patients.

METHODS

In this post hoc analysis, data from 20 randomized controlled trials were used to develop and test COPDCompEx. Diary events were tested against predefined threshold values for peak expiratory flow, reliever medication use, and symptoms. A COPDCompEx event was defined as first occurrence of a diary event, a moderate or severe exacerbation, or a study dropout. Ratios of event frequency, treatment effect and future trial sample size were compared between COPDCompEx and moderate and severe exacerbations.

FINDINGS

At 3 months, the proportion of patients experiencing COPDCompEx events increased over 3-fold versus exacerbations alone. All components contributed to COPDCompEx event rate. Treatment effects at 3 months were closely matched between COPDCompEx and exacerbations, and the large net gain in power substantially reduced the required sample size.

INTERPRETATION

COPDCompEx may be used to predict treatment effect on moderate and severe exacerbations of chronic obstructive pulmonary disease. This may enable the design of shorter Phase 2 clinical trials requiring fewer patients when compared with current exacerbation studies, with exacerbations as a key Phase 3 endpoint. This would, therefore, allow more efficient decision-making with reduced burden and risk to study participants.

Towards large-scale case-finding: training and validation of residual networks for detection of chronic obstructive pulmonary disease using low-dose CT

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is underdiagnosed in the community. Thoracic CT scans are widely used for diagnostic and screening purposes for lung cancer. In this proof-of-concept study, we aimed to evaluate a software pipeline for the automated detection of COPD, based on deep learning and a dataset of low-dose CTs that were performed for early detection of lung cancer.

METHODS

We examined the use of deep residual networks, a type of artificial residual network, for the automated detection of COPD. Three versions of the residual networks were independently trained to perform COPD diagnosis using random subsets of CT scans collected from the PanCan study, which enrolled ex-smokers and current smokers at high risk of lung cancer, and evaluated the networks using three-fold cross-validation experiments. External validation was performed using 2153 CT scans acquired from a separate cohort of individuals with COPD in the ECLIPSE study. Spirometric data were used to define COPD, with stages defined according to the GOLD criteria.

FINDINGS

The best performing networks achieved an area under the receiver operating characteristic curve (AUC) of 0·889 (SD 0·017) in three-fold cross-validation experiments. When the same set of networks was applied to the ECLIPSE cohort without any modifications to the trained models, they achieved an AUC of 0·886 (0·017), a positive predictive value of 0·847 (0·056), and a negative predictive value of 0·755 (0·097), which is a greater performance than the best quantitative CT measure, the percentage of lung volumes of less than or equal to -950 Hounsfield units (AUC 0·742).

INTERPRETATION

Our proposed approach could identify patients with COPD among ex-smokers and current smokers without a previous diagnosis of COPD, with clinically acceptable performance. The use of deep residual networks on chest CT scans could be an effective case-finding tool for COPD detection and diagnosis, particularly in ex-smokers and current smokers who are being screened for lung cancer.

FUNDING

Data Science Institute, University of British Columbia; Canadian Institutes of Health Research.

An accurate prediction model to identify undiagnosed at-risk patients with COPD: a cross-sectional case-finding study

Underuse or unavailability of spirometry is one of the most important factors causing underdiagnosis of COPD. We reported the development of a COPD prediction model to identify at-risk, undiagnosed COPD patients when spirometry was unavailable. This cross-sectional study enrolled subjects aged ≥40 years with respiratory symptoms and a smoking history (≥20 pack-years) in a medical center in two separate periods (development and validation cohorts). All subjects completed COPD assessment test (CAT), peak expiratory flow rate (PEFR) measurement, and confirmatory spirometry. A binary logistic model with calibration (Hosmer-Lemeshow test) and discrimination (area under receiver operating characteristic curve [AUROC]) was implemented. Three hundred and one subjects (development cohort) completed the study, including non-COPD (154, 51.2%) and COPD cases (147; stage I, 27.2%; II, 55.8%; III–IV, 17%). Compared with non-COPD and GOLD I cases, GOLD II-IV patients exhibited significantly higher CAT scores and lower lung function, and were considered clinically significant for COPD. Four independent variables (age, smoking pack-years, CAT score, and percent predicted PEFR) were incorporated developing the prediction model, which estimated the COPD probability (P_COPD). This model demonstrated favorable discrimination (AUROC: 0.866/0.828; 95% CI 0.825–0.906/0.751–0.904) and calibration (Hosmer-Lemeshow P = 0.332/0.668) for the development and validation cohorts, respectively. Bootstrap validation with 1000 replicates yielded an AUROC of 0.866 (95% CI 0.821–0.905). A P_COPD of ≥0.65 identified COPD patients with high specificity (90%) and a large proportion (91.4%) of patients with clinically significant COPD (development cohort). Our prediction model can help physicians effectively identify at-risk, undiagnosed COPD patients for further diagnostic evaluation and timely treatment when spirometry is unavailable.

Assessing Airflow Limitation among Smokers in a Primary Care Setting

Background

Many smokers have undiagnosed chronic obstructive pulmonary disease (COPD), and yet screening for COPD is not recommended. Smokers who know that they have airflow limitation are more likely to quit smoking. This study aims to identify the prevalence and predictors of airflow limitation among smokers in primary care.

Methods

Current smokers ≥ 40 years old who were asymptomatic clinic attendees in a primary care setting were recruited consecutively for two months. We used a two-step strategy. Step 1: participants filled in a questionnaire. Step 2: Assessment of airflow limitation using a pocket spirometer. Multiple logistic regression was utilised to determine the best risk predictors for airflow limitation.

Results

Three hundred participants were recruited. Mean age was 58.35 (SD 10.30) years old and mean smoking history was 34.56 pack-years (SD 25.23). One in two smokers were found to have airflow limitation; the predictors were Indian ethnicity, prolonged smoking pack-year history and Lung Function Questionnaire score ≤ 18. Readiness to quit smoking and the awareness of COPD were low.

Conclusions

The high prevalence of airflow limitation and low readiness to quit smoking imply urgency with helping smokers to quit smoking. Identifying airflow limitation as an additional motivator for smoking cessation intervention may be considered. A two-step case-finding method is potentially feasible.

Vaccination coverage and associated factors for receipt of the 23-valent pneumococcal polysaccharide vaccine in Taiwan: A nation-wide community-based study

Older adults, particularly those with chronic obstructive pulmonary disease, are advised to receive 23-valent pneumococcal polysaccharide vaccine (PPV23). However, the PPV23 vaccination rate in Taiwan and the determinants of receipt remain unclear.We analyzed the data of 1475 community-dwelling older adults aged ≥75 years who participated in the Healthy Aging Longitudinal Study in Taiwan. Each participant received assessments of PPV23 status, sociodemographic factors (age, sex, education level, marital status, living alone, and occupation), and health-related factors (chronic diseases, smoking status, alcohol intake, physical activities, cognitive status, and physical performance). PPV23 rate was defined as the number of participants who reported receiving free PPV23 divided by the total number of candidates for free PPV23. Multinomial logistic regression analysis was applied to investigate the sociodemographic and health-related determinants of PPV23 status.A PPV23 vaccination rate of 20.7% (305/1475) was observed. Participants who were female, current smokers, and had a low peak expiratory flow were associated with PPV23 nonreceipt (all P <.05). Of the participants who had a low peak expiratory flow, low education status, and physical inactivity were associated with PPV23 nonreceipt (all P <.05).The PPV23 vaccination rate among adults aged ≥75 years was low. Older adults who were women, current smokers, or who had a low PEF were less likely to receive the PPV23. These findings support continual efforts to improve the PPV23 coverage rate in vulnerable populations.

Joint statement for the diagnosis, management, and prevention of chronic obstructive pulmonary disease for Gulf Cooperation Council countries and Middle East-North Africa region, 2017

Smoking and subsequent development of COPD is an ever-increasing epidemic in Arabian Gulf and Middle East countries, with no signs of decline. The important fact to be highlighted is that this COPD epidemic of increasing incidence and prevalence is mostly unrecognized by patients, due to the common attribution of symptoms to "smoker's cough", and the underdiagnosis and undertreatment by physicians because the common signs and symptoms masquerade as asthma. Consequently, there are long-term adverse effects of missing the diagnosis. The purpose of this review article is to focus upon the status of COPD in Arabian Gulf and Middle East countries, stressing the increasing burden of smoking and COPD, to emphasize the specific factors leading to rise in prevalence of COPD, to bring to light the underdiagnosis and undermanagement of COPD, and to treat COPD in conformity with standard guidelines with local and regional modifications. This review ends with suggestions and recommendations to the health department to formulate policies and to generate awareness among the general public about the side effects of smoking and consequences of COPD.

Analysis of agreement between peak expiratory flow meters and comparison of reference values

Abstract Introduction: The peak expiratory flow (PEF) is a practical method that evaluates the caliber of the proximal airways. The ease in handling and the low cost of portable PEF meters made their use frequent. However, few studies have examined the correlation between the different equipment and compared their reference values. Objective: Analyze the correlation of three portable meters of PEF and check if the reference values are applicable in the studied population. Methods: 168 healthy individuals, of both genders, ranging in age from 20 to 80 years, had their PEF measured in Mini-Wright®, Assess® and AirZone® and the values obtained were compared to those predicted by Leiner et al. (1963) and Nunn and Gregg (1989). Statistical analysis was performed by the Kolmogorov-Smirnov tests, ANOVA, Wilcoxon test, Spearman correlation and analysis of agreement of Bland-Altman (p< 0.05). Results: There was significant difference in the values of PEF obtained between the Mini-Wright® and Assess® meters in both genders, between the AirZone® and Assess® only in men and between the Mini-Wright® and AirZone® only in women. The predicted values in the three meters have overestimated the obtained in both genders; there was no correlation between the values obtained from three meters due to the great variation of agreement limits and large interindividual variation. Conclusion: The values obtained in the three meters are not interchangeable and the predicted values were unsuitable for the sample.

Peak flow meter with a questionnaire and mini-spirometer to help detect asthma and COPD in real-life clinical practice: a cross-sectional study

Peak flow meter with questionnaire and mini-spirometer are considered as alternative tools to spirometry for screening of asthma and chronic obstructive pulmonary disease. However, the accuracy of these tools together, in clinical settings for disease diagnosis, has not been studied. Two hundred consecutive patients with respiratory complaints answered a short symptom questionnaire and performed peak expiratory flow measurements, standard spirometry with Koko spirometer and mini-spirometry (COPD-6). Spirometry was repeated after bronchodilation. Physician made a final diagnosis of asthma, chronic obstructive pulmonary disease and others. One eighty nine patients (78 females) with age 51 ± 17 years with asthma (115), chronic obstructive pulmonary disease (33) and others (41) completed the study. "Breathlessness > 6months" and "cough > 6months" were important symptoms to detect obstructive airways disease. "Asymptomatic period > 2 weeks" had the best sensitivity (Sn) and specificity (Sp) to differentiate asthma and chronic obstructive pulmonary disease. A peak expiratory flow of < 80% predicted was the best cut-off to detect airflow limitation (Sn 90%, Sp 50%). Respiratory symptoms with PEF < 80% predicted, had Sn 84 and Sp 93% to detect OAD. COPD-6 device under-estimated FEV1 by 13 mL (95% CI: -212, 185). At a cut-off of 0.75, the FEV1/FEV6 had the best accuracy (Sn 80%, Sp 86%) to detect airflow limitation. Peak flow meter with few symptom questions can be effectively used in clinical practice for objective detection of asthma and chronic obstructive pulmonary disease, in the absence of good quality spirometry. Mini-spirometers are useful in detection of obstructive airways diseases but FEV1 measured is inaccurate.

CHRONIC LUNG DISEASES

DIFFERENTIATING CONDITIONS IN POORLY-EQUIPPED SETTINGS: A simple questionnaire and peak flow meter measurements can help doctors differentiate between asthma and chronic lung disease. In clinical settings where access to specialist equipment and knowledge is limited, it can be challenging for doctors to tell the difference between asthma and chronic obstructive pulmonary disease (COPD). To determine a viable alternative method for differentiating between these diseases, Rahul Kodgule and colleagues at the Chest Research Foundation in Pune, India, trialed a simplified version of two existing symptom questionnaires, combined with peak flow meter measurements. They assessed 189 patients using this method, and found it aided diagnosis with high sensitivity and specificity. Breathlessness, cough and wheeze were the minimal symptoms required for COPD diagnosis, while the length of asymptomatic periods was most helpful in distinguishing asthma from COPD.

Diagnostic accuracy of a pocket screening spirometer in diagnosing chronic obstructive pulmonary disease in general practice: a cross sectional validation study using tertiary care as a reference

BACKGROUND

COPD-6™ is a lung function testing device for a rapid pre-spirometry testing to screen-out at-risk individuals not having COPD and indicating those at risk. The aim of this study was to validate COPD-6™ lung function testing (index test) in general practice in discriminating patients with COPD out of the population at risk - smokers/ex-smokers with no previous diagnosis of COPD, using measurements at tertiary care as reference standard.

METHODS

Consecutive 227 subjects (115 women, 185 smokers/42 ex-smokers, ≥20 pack-years) with no previous diagnosis of COPD, aged 52.5 (SD 6.8) years from 26 general practitioners (GPs) were recruited, lung function tested with COPD-6™, referred to the tertiary institution for repeated COPD-6™ testing followed by spirometry with a bronchodilator (salbutamol), examination, and pulmonologist consultation for the diagnosis and severity of COPD.

RESULTS

COPD was diagnosed in 43 subjects (18.9 %), with an AUC of 0.827 (95 % CI 0.769-0.875, P < 0.001) for the diagnosis of COPD when lung function was measured using COPD-6™ in GP's office with a specificity of 100 % (95 % CI, 97.95-100 %) but a very low sensitivity of 32.56 % (95 % CI, 20.49-47.48 %). Significant agreement for forced expiratory volume in 1 s measured at GP's office and at lung function lab was found (mean difference 0.01 L, p = 0.667) but not for other measured parameters (p < 0.001 for all).

CONCLUSIONS

Our study results point out that active case finding in a population at risk for COPD should be instituted (almost 20 % of undiagnosed COPD). Based on our results lung function testing with COPD-6™ can substitute spirometry testing in cases where it is not readily available to the patient/physician taken into account that the traditional FEV1/FEV6 cutoff value of <0.7 is not the only criterion for diagnosis and/or further referral.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01550679 Registered 28 September 2014, retrospectively registered.

Office-Based Case Finding for Chronic Obstructive Pulmonary Disease in Older Adults in Primary Care

Background. Chronic Obstructive Pulmonary Disease (COPD) is underdiagnosed in primary care. Aim. To explore the utility of proactive identification of COPD in patients 75 years of age and older in a Canadian primary care setting. Methods. Canadian Thoracic Society (CTS) screening questions were administered to patients with a smoking history of 20 pack-years or more; those with a positive screen were referred for postbronchodilator spirometry. Results. A total of 107 patients (21%), of 499 screened, had a 20-pack-year smoking history; 105 patients completed the CTS screening. Forty-four (42%) patients were positive on one or more questions on the screening; significantly more patients with a previous diagnosis of COPD (64%) were positive on the CTS compared to those without a previous diagnosis of COPD (30%). Of those who were not previously diagnosed with COPD (N = 11), four (36%) were newly diagnosed with COPD. Conclusion. A systematic two-stage method of screening for COPD, using CTS screening questions followed by spirometric confirmation, is feasible in the context of a busy primary care setting. More research is needed to assess the value of restricting screening to patients with a smoking history of 20 pack-years and on the sensitivity and specificity of these measures.

A retrospective study of two populations to test a simple rule for spirometry

Background

Chronic lung disease is common and often under-diagnosed.

Methods

To test a simple rule for conducting spirometry we reviewed spirograms from two populations, occupational medicine evaluations (OME) conducted by Saint Louis and Wake Forest Universities at 3 sites (n = 3260, mean age 64.14 years, 95 % CI 58.94–69.34, 97 % men) and conducted by Wake Forest University preop clinic (POC) at one site (n = 845, mean age 62.10 years, 95 % CI 50.46–73.74, 57 % men). This retrospective review of database information that the first author collected prospectively identified rates, types, sensitivity, specificity and positive and negative predictive value for lung function abnormalities and associated mortality rate found when conducting spirometry based on the 20/40 rule (≥20 years of smoking in those aged ≥ 40 years) in the OME population. To determine the reproducibility of the 20/40 rule for conducting spirometry, the rule was applied to the POC population.

Results

A lung function abnormality was found in 74 % of the OME population and 67 % of the POC population. Sensitivity of the rule was 85 % for an obstructive pattern and 77 % for any abnormality on spirometry. Positive and negative predictive values of the rule for a spirometric abnormality were 74 and 55 %, respectively. Patients with an obstructive pattern were at greater risk of coronary heart disease (odds ratio (OR) 1.39 [confidence interval (CI) 1.00–1.93] vs. normal) and death (hazard ratio (HR) 1.53, 95 % CI 1.20–1.84) than subjects with normal spirometry. Restricted spirometry patterns were also associated with greater risk of coronary disease (odds ratio (OR) 1.7 [CI 1.23–2.35]) and death (Hazard ratio 1.40, 95 % CI 1.08–1.72).

Conclusions

Smokers (≥ 20 pack years) age ≥ 40 years are at an increased risk for lung function abnormalities and those abnormalities are associated with greater presence of coronary heart disease and increased all-cause mortality. Use of the 20/40 rule could provide a simple method to enhance selection of candidates for spirometry evaluation in the primary care setting.

HIV and COPD: a conspiracy of risk factors

Chronic obstructive pulmonary disease (COPD) is an under recognized complication of HIV infection. It is estimated that up to 25% of HIV infected people may have COPD. HIV is associated with COPD as a result of a complex interplay of multiple factors such as pulmonary inflammation, recurrent pulmonary infections especially tuberculosis (TB), increased cigarette smoking, socio-economic status, childhood respiratory illnesses and industrial and environmental exposures; each of which are risk factors for COPD in their own right. COPD presents at an earlier age in people with HIV infection. There are over 35 million people living with HIV, and most people infected with HIV live in developing regions of the world where they are faced with multiple risk factors for COPD and suboptimal access to health care. TB is the commonest infectious complication of HIV, and HIV infected persons often experience multiple episodes of TB. Cigarette smoking is increasing in developing countries where the greatest burden of TB and HIV is experienced. Cigarette smoking is associated with increased risk of TB and may be associated with acquisition of HIV infection and progression. It is not clear whether non-infectious pulmonary inflammation persists in the lung when immune reconstitution occurs. Prevention and control of HIV infection must be part of the multiple interventions to reduce the global burden of COPD. A multidisciplinary approach, including behavioural science is required to address this challenge. It presents research opportunities that should be driven by the pulmonology community.

Risk stratification for COPD diagnosis through an active search strategy in primary care

Background

The aim of this study was to identify the percentage of undiagnosed patients with COPD through the implementation of an active search strategy in a selected subject population.

Methods

An observational, cross-sectional, multicenter study was conducted in a primary care setting in Spain. General practitioners gave their diagnostic impression of COPD (yes/no) on the basis of clinical criteria of subjects with respiratory symptoms and tobacco exposure. Subsequently, post-bronchodilator spirometry and quality-of-life tests were performed. Multivariate logistic regression techniques using receiver operating characteristic (ROC) curves were used to identify the combination of variables that best discriminates COPD.

Results

A total of 2,758 patients were screened at 368 primary care centers, of which 1,725 patients were included in the study. Seven hundred and ninety-three patients (46%) were diagnosed with COPD. Clinical judgment resulted in suspected COPD in 1,393 (81%) of the subjects. The best variables to discriminate COPD were a history of lower respiratory tract infections, cough, and dyspnea. This combination identified COPD with a ROC_AUC of 0.61 denoting a poor discriminative ability.

Conclusion

Employing an active search strategy leads to a new COPD diagnosis in almost half of the subjects. Screening of COPD with post-bronchodilator spirometry should be considered mandatory for any high-risk subject visiting the general practitioner clinic for any reason.

Burden of asthma and chronic obstructive pulmonary disease and access to essential medicines in low-income and middle-income countries

Demographic and epidemiological transitions are changing the age structure of the population and the most common diseases. Non-communicable respiratory diseases are an increasing problem at both ends of the age range in low-income and middle-income countries. In children, who represent a large proportion of the total population, the increasing problem of asthma is a strain on health services. Improved survival of the older population is increasing the proportion of morbidity and mortality attributable to chronic lung diseases. Health services in low-resource countries are poorly adapted to treating chronic diseases. Designed to respond episodically to acute disease, almost all historical investment has focused on infectious diseases. Crucial to the successful management of chronic diseases is an infrastructure designed to support pro-active management, providing not only an accurate diagnosis, but also a secure supply of cost effective drugs at an affordable price. The absence of such an infrastructure in many countries and the market failure that makes drugs generally more expensive in low-resource regions means that many people with chronic non-communicable lung diseases are not given effective treatment. This has damaging economic consequences. The common causes of poor lung health in low-income countries are not the same as those in richer countries, and there is a need to study why they are so common and how best to manage them.

Insight into Best Variables for COPD Case Identification: A Random Forests Analysis

RATIONALE

This study is part of a larger, multi-method project to develop a questionnaire for identifying undiagnosed cases of chronic obstructive pulmonary disease (COPD) in primary care settings, with specific interest in the detection of patients with moderate to severe airway obstruction or risk of exacerbation.

OBJECTIVES

To examine 3 existing datasets for insight into key features of COPD that could be useful in the identification of undiagnosed COPD.

METHODS

Random forests analyses were applied to the following databases: COPD Foundation Peak Flow Study Cohort (N=5761), Burden of Obstructive Lung Disease (BOLD) Kentucky site (N=508), and COPDGene® (N=10,214). Four scenarios were examined to find the best, smallest sets of variables that distinguished cases and controls:(1) moderate to severe COPD (forced expiratory volume in 1 second [FEV1] <50% predicted) versus no COPD; (2) undiagnosed versus diagnosed COPD; (3) COPD with and without exacerbation history; and (4) clinically significant COPD (FEV1<60% predicted or history of acute exacerbation) versus all others.

RESULTS

From 4 to 8 variables were able to differentiate cases from controls, with sensitivity ≥73 (range: 73-90) and specificity >68 (range: 68-93). Across scenarios, the best models included age, smoking status or history, symptoms (cough, wheeze, phlegm), general or breathing-related activity limitation, episodes of acute bronchitis, and/or missed work days and non-work activities due to breathing or health.

CONCLUSIONS

Results provide insight into variables that should be considered during the development of candidate items for a new questionnaire to identify undiagnosed cases of clinically significant COPD.

Effectiveness of case finding strategies for COPD in primary care: a systematic review and meta-analysis

Background:

Chronic obstructive pulmonary disease (COPD) is widely underdiagnosed, but the most effective approach for identifying these patients is unknown.

Aims:

The aim of this study was to summarise and compare the effectiveness of different case finding approaches for undiagnosed COPD in primary care.

Methods:

A systematic review of primary studies of any design evaluating case finding strategies for COPD in primary care among individuals aged ⩾35 years with no prior diagnosis was conducted. Medline, Embase and other bibliographic databases were searched from 1997 to 2013, and methodological quality was assessed using standard tools. Results were described and meta-analysis of the uptake and yield from different approaches was performed where there was sufficient homogeneity.

Results:

Three randomised controlled trials (RCTs), 1 controlled trial and 35 uncontrolled studies were identified that assessed the identification of new cases of COPD through systematic case finding. A range of approaches were used including pre-screening with questionnaires (n=13) or handheld flow meters (n=5) or direct invitation to diagnostic spirometry (n=30). Overall, any approach identified more undiagnosed COPD compared with usual care. Targeting those at higher risk (e.g., smokers) and pre-screening (e.g., using questionnaires) is likely to increase the yield. However, studies were heterogeneous and were limited by a lack of comparison groups, inadequate reporting and diversity in the definition of COPD, which limited our ability to draw firm conclusions.

Conclusions:

There is extensive heterogeneity among studies evaluating case finding strategies for COPD, with few RCTs. Well-conducted RCTs comparing case finding approaches are needed to identify the most effective target population, recruitment strategy and screening tests, using a clinical definition of COPD, and addressing the limitations highlighted in this review. There is also a need to evaluate the impact of case finding on clinical care and patient outcomes.

Peak expiratory flow rate as a surrogate for forced expiratory volume in 1 second in COPD severity classification in Thailand

BACKGROUND

There are limited studies directly comparing correlation and agreement between peak expiratory flow rate (PEFR) and forced expiratory volume in 1 second (FEV1) for severity classification of COPD. However, clarifying the role of PEFR as a surrogate of COPD severity classification instead of FEV1 is essential in situations and areas where spirometry is not routinely available.

PURPOSE

To evaluate the agreement between FEV1 and PEFR using Global initiative for chronic Obstructive Lung Disease (GOLD) severity classification criteria.

MATERIALS AND METHODS

This cross-sectional study included stable COPD patients. Both absolute values and % predicted FEV1 and % predicted PEFR were obtained from the same patients at a single visit. The severity of COPD was classified according to GOLD criteria. Pearson's correlation coefficient was used to examine the relationship between FEV1 and PEFR. The agreement of % predicted FEV1 and % predicted PEFR in assigning severity categories was calculated using Kappa statistic, and identification of the limits of agreement was by Bland-Altman analysis. Statistical significance was set at P-value <0.05.

RESULTS

Three hundred stable COPD patients were enrolled; 195 (65.0%) male, mean age 70.4±9.4 years, and mean % predicted FEV1 51.4±20.1. Both correlations between the % predicted FEV1 and PEFR as well as the absolute values were strongly significant (r=0.76, P<0.001 and r=0.87, P<0.001, respectively). However, severity categories of airflow limitation based on % predicted FEV1 or PEFR intervals were concordant in only 179 patients (59.7%). The Kappa statistic for agreement was 0.41 (95% confidence interval, 0.34-0.48), suggesting unsatisfied agreement. The calculated limits of agreement were wide (+27.1% to -28.9%).

CONCLUSION

Although the correlation between FEV1 and PEFR measurements were strongly significant, the agreement between the two tests was unsatisfied and may influence inappropriate clinical decision making in diagnosis, severity classification, and management of COPD.

Identifying cases of undiagnosed, clinically significant COPD in primary care: qualitative insight from patients in the target population

Background:

Many cases of chronic obstructive pulmonary disease (COPD) are diagnosed only after significant loss of lung function or during exacerbations.

Aims:

This study is part of a multi-method approach to develop a new screening instrument for identifying undiagnosed, clinically significant COPD in primary care.

Methods:

Subjects with varied histories of COPD diagnosis, risk factors and history of exacerbations were recruited through five US clinics (four pulmonary, one primary care). Phase I: Eight focus groups and six telephone interviews were conducted to elicit descriptions of risk factors for COPD, recent or historical acute respiratory events, and symptoms to inform the development of candidate items for the new questionnaire. Phase II: A new cohort of subjects participated in cognitive interviews to assess and modify candidate items. Two peak expiratory flow (PEF) devices (electronic, manual) were assessed for use in screening.

Results:

Of 77 subjects, 50 participated in Phase I and 27 in Phase II. Six themes informed item development: exposure (smoking, second-hand smoke); health history (family history of lung problems, recurrent chest infections); recent history of respiratory events (clinic visits, hospitalisations); symptoms (respiratory, non-respiratory); impact (activity limitations); and attribution (age, obesity). PEF devices were rated easy to use; electronic values were significantly higher than manual (P<0.0001). Revisions were made to the draft items on the basis of cognitive interviews.

Conclusions:

Forty-eight candidate items are ready for quantitative testing to select the best, smallest set of questions that, together with PEF, can efficiently identify patients in need of diagnostic evaluation for clinically significant COPD.

Airflow obstruction case finding in community-pharmacies: a novel strategy to reduce COPD underdiagnosis

BACKGROUND

Community pharmacies (CP) have access to subjects at high-risk of suffering Chronic Obstructive Pulmonary Disease (COPD). We investigated if a COPD case finding program in CP could be a new strategy to reduce COPD underdiagnosis.

METHODS

Prospective, cross-sectional, descriptive, uncontrolled, remotely supported study in 100 CP in Barcelona, Spain. Pharmacists were trained in a four-day workshop on spirometry and COPD, and each was provided with a spirometer for 12 weeks. The program included questionnaires and forced spirometry measurements, whose quality was controlled and monitored by web-assistance.

FINDINGS

Overall 2295 (73.5%), of 3121 CP customers invited to participate in the program accepted, and 1.456 (63.4%) were identified as "high risk" for COPD using the GOLD questionnaire. Only 33 could not conduct spirometry, and a pre-bronchodilator airflow limitation (FEV1/FVC ratio <0.7) was confirmed in 282 (19.8%); 244 of these were referred to their primary care (PC) physician for further diagnostic and therapeutic work-up, but only 39 of them (16%) fed-back this information to the pharmacist. Clinically acceptable quality spirometries (grade A or B) were obtained in 69.4% of the cases.

CONCLUSION

This study shows that adequately trained and supported community pharmacists can effectively identify individuals at high risk of having COPD and can thus contribute to ameliorate underdiagnosis in this disease. Links between PC and CP should be improved to achieve a useful program.

ALAT-2014 Chronic Obstructive Pulmonary Disease (COPD) Clinical Practice Guidelines: questions and answers

ALAT-2014 COPD Clinical Practice Guidelines used clinical questions in PICO format to compile evidence related to risk factors, COPD screening, disease prognosis, treatment and exacerbations. Evidence reveals the existence of risk factors for COPD other than tobacco, as well as gender differences in disease presentation. It shows the benefit of screening in an at-risk population, and the predictive value use of multidimensional prognostic indexes. In stable COPD, similar benefits in dyspnea, pulmonary function and quality of life are achieved with LAMA or LABA long-acting bronchodilators, whereas LAMA is more effective in preventing exacerbations. Dual bronchodilator therapy has more benefits than monotherapy. LAMA and combination LABA/IC are similarly effective, but there is an increased risk of pneumonia with LABA/IC. Data on the efficacy and safety of triple therapy are scarce. Evidence supports influenza vaccination in all patients and anti-pneumococcal vaccination in patients <65years of age and/or with severe airflow limitation. Antibiotic prophylaxis may decrease exacerbation frequency in patients at risk. The use of systemic corticosteroids and antibiotics are justified in exacerbations requiring hospitalization and in some patients managed in an outpatient setting.

Validation of the COPD Diagnostic Questionnaire in an Australian general practice cohort: a cross-sectional study

BACKGROUND

The gold standard for the diagnosis of chronic obstructive pulmonary disease (COPD) is spirometry, but there are barriers to its use in primary care.

AIMS

To externally validate the COPD Diagnostic Questionnaire (CDQ) as a diagnostic tool in patients at increased risk in Australian general practice and to compare its performance with other CDQ validation studies.

METHODS

Patients were recruited from 36 general practices in Sydney, Australia. Former or current smokers aged 40-85 years with no prior COPD diagnosis were invited to a case-finding appointment with the practice nurse. The CDQ was collected and pre- and postbronchodilator spirometry was performed. Cases for whom complete CDQ data were present and the spirometry met quality standards were analysed.

RESULTS

Of 1,631 patients who attended case-finding recruitment, 1,054 (65%) could be analysed. Spirometry showed 13% had COPD. The ability of the CDQ to discriminate between patients with and without COPD was fair, represented by the area under the receiver operating characteristic curve of 0.713. With a CDQ cut-off point value of 16.5 the sensitivity was 80% and specificity 47% and, at a cut-off point value of 19.5, the sensitivity was 63% and specificity 70%.

CONCLUSIONS

The CDQ did not discriminate between patients with and without COPD accurately enough to use as a diagnostic tool in patients at increased risk of COPD in Australian general practice. Further research is needed on the value of the CDQ as a tool for selecting patients for spirometry.

[Clinical and functional assessment in COPD: from case finding to follow-up]

A spirometry with bronchodilator test is needed for the diagnosis of COPD. It is recommended to detect COPD only in subjects with symptoms (dyspnoea and/or chronic cough and/or chronic sputum production) and a history of exposure to risk factors for the disease (tobacco smoking and/or occupational exposure). Measurement of peak expiratory flow to detect COPD, although simpler than conventional spirometry, allows only detection of the most severe cases of COPD. Specialist referral is often useful in the diagnosis of COPD, to establish the presence of incompletely reversible airflow obstruction, assess severity (using clinical questionnaires, plethysmography, exercise testing and arterial blood gases when indicated) and define future management. The level of FEV1 is associated with individualized assessment of symptoms and evaluation of exacerbation risk in the management strategy of stable COPD.

Improving early-stage diagnosis and management of COPD in primary care

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease, but it often remains undetected in its mild and moderate forms. Patients frequently remain undiagnosed and untreated until the disease has become severe and debilitating, greatly impacting their quality of life. Primary care physicians (PCPs) are most often the first point of contact, and therefore they are in the best position to identify patients at risk of COPD in the early stages. Consequently, they play a critical role in the management of the disease, particularly smoking cessation. One of the earliest symptoms is activity-related dyspnea and subsequent exercise intolerance, often compensated for by reduction in physical activity. This review addresses the approaches used to identify COPD in the primary care setting, including simple tools such as handheld spirometers and questionnaires. A recent study demonstrated that, compared with usual care, use of the COPD Population Screener questionnaire alone and in combination with the copd-6 handheld spirometer significantly improved the odds of referral of patients with suspected COPD for pulmonary function testing or to a pulmonologist. Identification of patients suspected of having the disease and differentiation of COPD from asthma are important in order that treatment can be initiated in the mild stages to slow or prevent disease progression and reduce the risk of exacerbations. The review also discusses the evidence to date on pharmacologic treatment using short-acting and long-acting anticholinergics and β2-agonists, and nonpharmacologic interventions, such as smoking cessation, pulmonary rehabilitation, and influenza and pneumococcal vaccination in patients with mild and moderate COPD.

Efficient screening for COPD using three steps: a cross-sectional study in Mexico City

BACKGROUND

Underdiagnosis of chronic obstructive pulmonary disease (COPD) in primary care can be improved by a more efficient screening strategy.

AIMS

To evaluate a three-step method of screening for COPD consisting of an initial short questionnaire followed by measurement of forced expiratory volume in 1s/forced expiratory volume in 6s (FEV1/FEV6) using an inexpensive pocket spirometer in those with high risk, and diagnostic quality spirometry in those with a low FEV1/FEV6.

METHODS

We analysed two related Mexico City cross-sectional samples. The 2003 Mexico City PLATINO survey (n=542) was used to develop a short questionnaire to determine the risk of COPD and a 2010 survey (n=737) additionally used a pocket spirometer. The discriminatory power of the two instruments was assessed with receiver operator characteristic (ROC) curves using three COPD definitions.

RESULTS

The developed COPD scale included two variables from a simple questionnaire and, in ROC analysis, an area under the curve (AUC) between 0.64 and 0.77 was found to detect COPD. The pocket spirometer had an AUC between 0.85 and 0.88 to detect COPD. Using the COPD scale as a first screening step excluded 35-48% of the total population from further testing at the cost of not detecting 8-18% of those with COPD. Using the pocket spirometer and sending those with a FEV1/FEV6<0.80 for diagnostic quality spirometry is very efficient, and substantially improved the positive predictive value at the cost of not detecting one-third of COPD cases.

CONCLUSIONS

A three-step screening strategy for COPD substantially reduces the need for spirometry testing when only a COPD scale is used for screening.

Case-finding of chronic obstructive pulmonary disease with questionnaire, peak flow measurements and spirometry: a cross-sectional study

Background

Spirometry is commonly accepted as the gold standard for the diagnosis of COPD, but the reality remains that quality assured spirometry is not or cannot be provided universally around the globe. Adding PEF measurement to a screening questionnaire may rule out airflow limitation compatible with COPD rationalizing spirometry testing.

Methods

We conducted a cross-sectional survey in a sample of individuals 40–80 yrs. old in Dubai, UAE. They were invited to answer a short socio-demographic questionnaire including a report on current, past history of smoking, and had PEF measured, then they conducted spirometry to identify airflow limitation compatible with COPD.

Results

Overall, 525 (91.0%) participants performed PEF and spirometry (68% male, with a mean age of 59 years, 17% UAE Nationals), 24% reported smoking of different sorts. Overall, 68 participants (12.9%, 95% C.I. 10.3% to 16.1%) had airflow limitation compatible with COPD. PEFR alone identified 141participants with airflow limitation compatible with COPD, with specificity of 80% and sensitivity of 73.5%.

Conclusions

PEFR could be an easy, cheap, and non-biased tool to assist with the case-finding of COPD before confirmation with spirometry.

Emphysema predicts hospitalisation and incident airflow obstruction among older smokers: a prospective cohort study

BACKGROUND

Emphysema on CT is common in older smokers. We hypothesised that emphysema on CT predicts acute episodes of care for chronic lower respiratory disease among older smokers.

MATERIALS AND METHODS

Participants in a lung cancer screening study age ≥ 60 years were recruited into a prospective cohort study in 2001-02. Two radiologists independently visually assessed the severity of emphysema as absent, mild, moderate or severe. Percent emphysema was defined as the proportion of voxels ≤ -910 Hounsfield Units. Participants completed a median of 5 visits over a median of 6 years of follow-up. The primary outcome was hospitalization, emergency room or urgent office visit for chronic lower respiratory disease. Spirometry was performed following ATS/ERS guidelines. Airflow obstruction was defined as FEV1/FVC ratio <0.70 and FEV1<80% predicted.

RESULTS

Of 521 participants, 4% had moderate or severe emphysema, which was associated with acute episodes of care (rate ratio 1.89; 95% CI: 1.01-3.52) adjusting for age, sex and race/ethnicity, as was percent emphysema, with similar associations for hospitalisation. Emphysema on visual assessment also predicted incident airflow obstruction (HR 5.14; 95% CI 2.19-21.1).

CONCLUSION

Visually assessed emphysema and percent emphysema on CT predicted acute episodes of care for chronic lower respiratory disease, with the former predicting incident airflow obstruction among older smokers.

Early chronic obstructive pulmonary disease: Beyond spirometry

The significant healthcare burden associated with chronic obstructive pulmonary disease (COPD) is driving us to improve our understanding of the natural history of this disease. Historically, the focus has been largely centred on diagnosing and treating individuals with moderate and severe disease. However, it is now recognised that the speed of decline in lung function as measured by forced expiratory volume in 1 s occurs faster in the earlier stages of the disease process. As a result, a clearer understanding of the potential benefits of treatment in early COPD is needed. It is recognised that many patients with COPD remain undiagnosed in the community which has prompted global case-finding initiatives. In this review we discuss the difficulties in diagnosing COPD in its early stages, examine the role of case-finding and look at the evidence for early intervention with therapeutic agents. There is a growing interest in the phenotypic variation amongst patients with COPD and we explore the role of phenotyping in early COPD and its potential benefits in providing a more individualised approach to COPD management. The majority of patients with COPD are known to die from non-respiratory causes such as cardiovascular disease. The mechanistic link is thought to relate to systemic inflammation, causing us to question whether earlier interventions could have a beneficial impact on the burden of co-morbidities for patients with COPD.

Challenges of COPD diagnosis

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide and this burden is predicted to increase unless exposure to risk factors is addressed. Diagnosis of COPD is a challenge: COPD is underdiagnosed and frequently misdiagnosed for asthma or other respiratory conditions. Although spirometry is only one parameter for establishing a clinical diagnosis of COPD, lack of routine spirometry is a key cause of COPD misdiagnosis. Differential diagnosis from asthma is essential because the treatment strategies for, and progression and outcomes of, the two conditions vary greatly.

AREAS COVERED

Here the authors review methods for the differential diagnosis of COPD and asthma; approaches to improve diagnosis, including case-finding and screening; the identification of specific COPD phenotypes and targeted therapy; and the potential role of exhaled biomarkers in the diagnosis of COPD.

EXPERT OPINION

Methods to diagnose COPD, specifically differential diagnosis from asthma, have improved in recent years. To translate these into clinical practice will require the development of combined guidelines for COPD and asthma that include COPD-asthma overlap syndrome and are based on evidence from randomized controlled trials.