Undiagnosed COPD Research Articles

Impact of Dyspnea on Adults With Respiratory Symptoms Without a Defined Diagnosis

BackgroundWe investigated dyspnea, its associated risk factors, and its impact on healthcare utilization, quality of life, and work productivity in adults with undiagnosed respiratory symptoms. Research QuestionWhat is the impact of dyspnea in adults with undiagnosed respiratory symptoms? Study Design and MethodsThis population-based study included 2857 adults who were experiencing respiratory symptoms. These individuals had not been previously diagnosed with any lung conditions and were recruited from 17 Canadian centers using random digit-dialing. Each participant underwent spirometry testing both before and after using a bronchodilator to determine if they met the diagnostic criteria for COPD, asthma, Preserved Ratio Impaired Spirometry (PRISm), or if their spirometry results were normal. An age-matched control group (n= 231) was similarly recruited using random-digit dialing. A dyspnea impact assessment score from 0 to 100 was produced using questions from the COPD Assessment Test and St. George’s Respiratory Questionnaire. ResultsIndividuals with PRISm (n=172) reported more impactful dyspnea (mean score 63.0, 95% CI: 59.5- 66.4) than those with undiagnosed asthma (n=265, mean score 56.6, 95% CI: 53.9-59.3) or undiagnosed COPD (n=330, mean score 57.5, 95% CI: 55.1-59.9). All groups reported significantly more impactful dyspnea compared to controls (mean score 13.8, 95% CI:11.8-15.7). Subject-specific risk factors including age, sex, BMI, smoking, and comorbidities explained 20.6% of the variation in dyspnea. An additional 12.4% of the variation was explained by disease classification and another 1.7% by the severity of lung function impairment assessed with spirometry. After adjusting for age, sex, and BMI, greater dyspnea impact was associated with increased healthcare utilization, lower quality of life, and reduced work productivity. InterpretationIn community-based adults with undiagnosed respiratory symptoms, those identified with PRISm experienced the greatest impact of dyspnea. Dyspnea imposes burdens on the healthcare system and is associated with impaired quality of life and work productivity.

The Accuracy of PUMA Questionnaire in Combination With Peak Expiratory Flow Rate to Identify At-risk, Undiagnosed COPD Patients

IntroductionThe English PUMA questionnaire emerges as an effective COPD case-finding tool. We aimed to use the PUMA questionnaire in combination with peak expiratory flow rate (PEFR) to improve case-finding efficacy in Chinese population. MethodsThis cross-sectional, observational study included two stages: translating English to Chinese PUMA (C-PUMA) questionnaire with linguistic validation and psychometric evaluation, followed by clinical validation. Eligible participants (with age ≥40 years, respiratory symptoms, smoking history ≥10 pack-years) were enrolled and subjected to three questionnaires (C-PUMA, COPD assessment test [CAT], and generic health survey [SF-12V2]), PEFR measurement, and confirmatory spirometry. The C-PUMA score and PEFR were incorporated into a PUMA-PEFR prediction model applying binary logistic regression coefficients to estimate the probability of COPD (PCOPD). ResultsC-PUMA was finalized through standard forward–backward translation processes and confirmation of good readability, comprehensibility, and reliability. In clinical validation, 240 participants completed the study. 78/240 (32.5%) were diagnosed with COPD. C-PUMA exhibited significant validity (correlated with CAT or physical component scores of SF-12V2, both P<0.05, respectively). PUMA-PEFR model had higher diagnostic accuracy than C-PUMA alone (area under ROC curve, 0.893 vs. 0.749, P<0.05). The best cutoff values of C-PUMA and PUMA-PEFR model (PCOPD) were ≥6 and ≥0.39, accounting for a sensitivity/specificity/numbers needed to screen of 77%/64%/3 and 79%/88%/2, respectively. C-PUMA ≥5 detected more underdiagnosed patients, up to 11.5% (vs. C-PUMA ≥6). ConclusionC-PUMA is well-validated. The PUMA-PEFR model provides more accurate and cost-effective case-finding efficacy than C-PUMA alone in at-risk, undiagnosed COPD patients. These tools can be useful to detect COPD early.

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

COPD is underdiagnosed, and measurement of spirometry alongside low-dose computed tomography (LDCT) screening for lung cancer is one strategy to increase earlier diagnosis of this disease. Ever-smokers at high risk of lung cancer were invited to the Yorkshire Lung Screening Trial for a lung health check (LHC) comprising LDCT screening, pre-bronchodilator spirometry and a smoking cessation service. In this cross-sectional study we present data on participant demographics, respiratory symptoms, lung function, emphysema on imaging and both self-reported and primary care diagnoses of COPD. Multivariable logistic regression analysis identified factors associated with possible underdiagnosis and misdiagnosis of COPD in this population, with airflow obstruction defined as forced expiratory volume in 1 s/forced vital capacity ratio <0.70. Out of 3920 LHC attendees undergoing spirometry, 17% had undiagnosed airflow obstruction with respiratory symptoms, representing potentially undiagnosed COPD. Compared to those with a primary care COPD code, this population had milder symptoms, better lung function and were more likely to be current smokers (p≤0.001 for all comparisons). Out of 836 attendees with a primary care COPD code who underwent spirometry, 19% did not have airflow obstruction, potentially representing misdiagnosed COPD, although symptom burden was high. Spirometry offered alongside LDCT screening can potentially identify cases of undiagnosed and misdiagnosed COPD. Future research should assess the downstream impact of these findings to determine whether any meaningful changes to treatment and outcomes occur, and to assess the impact on co-delivering spirometry on other parameters of LDCT screening performance such as participation and adherence. Additionally, work is needed to better understand the aetiology of respiratory symptoms in those with misdiagnosed COPD, to ensure that this highly symptomatic group receive evidence-based interventions.

Use of CAPTURE to Identify Individuals Who May or May Not Require Treatment for COPD.

The COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE) tool was developed to identify patients with undiagnosed COPD with FEV1 <60% predicted or risk of exacerbation as treatment criteria. To test the ability of CAPTURE to identify patients requiring treatment because of symptoms or risk of exacerbation or hospitalization. Data were from COMPASS, a prospective study in China of COPD, chronic bronchitis without airflow limitation (post-bronchodilator FEV1/FVC >0.70), and healthy never-smokers. CAPTURE was tested as questions alone and with peak expiratory flow (PEF). Sensitivity, specificity, positive and negative predicted values (PPV and NPV) were calculated for CAT ≥10 vs <10, mMRC ≥2 vs <2, and ≥1 moderate exacerbation or hospitalization vs none in the previous year. COPD patients (n=1696), mean age 65±7.5 years, 90% males, post-bronchodilator FEV1 66.5±20.1% pred; controls (n=307), age 60.2±7.0 years, 65% males, FEV1/FVC 0.78±0.04. CAPTURE using PEF showed the best combination of sensitivity and specificity. Sensitivity and specificity to detect CAT ≥10 were 68.5% and 64.0%, respectively; mMRC ≥2 (85.6% and 61.0%), ≥1 moderate exacerbation (63.5% and 55.6%) and hospitalization (70.2% and 59.4%). PPV ranged 15.6% (moderate exacerbations) to 47.8% (CAT). NPV ranged 80.8% (CAT) to 95.6% (mMRC). CAPTURE has good sensitivity to identify COPD patients who may require treatment because of elevated symptoms, risk of exacerbations or hospitalization, including those with FEV1 >60% predicted. High NPV values show it can also exclude those who may not require treatment. GSK (208630).

Impaired Spirometry and COPD Increase the Risk of Cardiovascular Disease: A Canadian Cohort Study

Individuals with COPD and preserved ratio impaired spirometry (PRISm) findings in clinical settings have an increased risk of cardiovascular disease (CVD). Do individuals with mild to moderate or worse COPD and PRISm findings in community settings have a higher prevalence and incidence of CVD compared with individuals with normal spirometry findings? Can CVD risk scores be improved when impaired spirometry is added? The analysis was embedded in the Canadian Cohort Obstructive Lung Disease (CanCOLD). Prevalence of CVD (ischemic heart disease [IHD] and heart failure [HF]) and their incidence over 6.3 years were compared between groups with impaired and normal spirometry findings using logistic regression and Cox models, respectively, adjusting for covariables. Discrimination of the pooled cohort equations (PCE) and Framingham risk score (FRS) in predicting CVD were assessed with and without impaired spirometry. Participants (n= 1,561) included 726 people with normal spirometry findings and 835 people with impaired spirometry findings (COPD Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 1 disease, n= 408; GOLD stage≥ 2, n= 331; PRISm findings, n= 96). Rates of undiagnosed COPD were 84%in GOLD stage 1 and 58%in GOLD stage≥ 2 groups. Prevalence of CVD (IHD or HF) was significantly higher among individuals with impaired spirometry findings and COPD compared with those with normal spirometry findings, with ORs of 1.66 (95%CI, 1.13-2.43; P= .01∗) (∗ indicates statistical significane with P < .05) and 1.55 (95%CI, 1.04-2.31; P= .033∗), respectively. Prevalence of CVD was significantly higher in participants having PRISm findings and COPD GOLD stage≥ 2, but not GOLD stage 1. CVD incidence was significantly higher, with hazard ratios of 2.07 (95%CI, 1.10-3.91; P= .024∗) for the impaired spirometry group and 2.09 (95%CI, 1.10-3.98; P= .024∗) for the COPD group compared to individuals with normal spirometry findings. The difference was significantly higher among individuals with COPD GOLD stage≥ 2, but not GOLD stage 1. The discrimination for predicting CVD was low and limited when impaired spirometry findings were added to either risk score. Individuals with impaired spirometry findings, especially those with moderate or worse COPD and PRISm findings, have increased comorbid CVD compared with their peers with normal spirometry findings, and having COPD increases the risk of CVD developing.

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.

Patient and physician factors associated with symptomatic undiagnosed asthma or COPD.

It remains unclear why some symptomatic individuals with asthma or COPD remain undiagnosed. Here, we compare patient and physician characteristics between symptomatic individuals with obstructive lung disease (OLD) who are undiagnosed and individuals with physician-diagnosed OLD. Using random-digit dialling and population-based case finding, we recruited 451 participants with symptomatic undiagnosed OLD and 205 symptomatic control participants with physician-diagnosed OLD. Data on symptoms, quality of life and healthcare utilisation were analysed. We surveyed family physicians of participants in both groups to elucidate differences in physician practices that could contribute to undiagnosed OLD. Participants with undiagnosed OLD had lower mean pre-bronchodilator forced expiratory volume in 1 s percentage predicted compared with those who were diagnosed (75.2% versus 80.8%; OR 0.975, 95% CI 0.963-0.987). They reported greater psychosocial impacts due to symptoms and worse energy and fatigue than those with diagnosed OLD. Undiagnosed OLD was more common in participants whose family physicians were practising for >15 years and in those whose physicians reported that they were likely to prescribe respiratory medications without doing spirometry. Undiagnosed OLD was more common among participants who had never undergone spirometry (OR 10.83, 95% CI 6.18-18.98) or who were never referred to a specialist (OR 5.92, 95% CI 3.58-9.77). Undiagnosed OLD was less common among participants who had required emergency department care (OR 0.44, 95% CI 0.20-0.97). Individuals with symptomatic undiagnosed OLD have worse pre-bronchodilator lung function and present with greater psychosocial impacts on quality of life compared with their diagnosed counterparts. They were less likely to have received appropriate investigations and specialist referral for their respiratory symptoms.

Detection of COPD in the SUMMIT Study lung cancer screening cohort using symptoms and spirometry.

COPD is a major comorbidity in lung cancer screening (LCS) cohorts, with a high prevalence of undiagnosed COPD. Combining symptom assessment with spirometry in this setting may enable earlier diagnosis of clinically significant COPD and facilitate increased understanding of lung cancer risk in COPD. In this study, we wished to understand the prevalence, severity, clinical phenotype and lung cancer risk of individuals with symptomatic undiagnosed COPD in a LCS cohort. 16 010 current or former smokers aged 55-77 years attended a lung health check as part of the SUMMIT Study. A respiratory consultation and spirometry were performed alongside LCS eligibility assessment. Those with symptoms, no previous COPD diagnosis and airflow obstruction were labelled as undiagnosed COPD. Baseline low-dose computed tomography (LDCT) was performed in those at high risk of lung cancer (PLCOm2012 score ≥1.3% and/or meeting USPSTF 2013 criteria). Nearly one in five (19.7%) met criteria for undiagnosed COPD. Compared with those previously diagnosed, those undiagnosed were more likely to be male (59.1% versus 53.2%; p<0.001), currently smoking (54.9% versus 47.6%; p<0.001) and from an ethnic minority group (p<0.001). Undiagnosed COPD was associated with less forced expiratory volume in 1 s impairment (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2: 85.3% versus 68.4%; p<0.001) and lower symptom/exacerbation burden (GOLD A and B groups: 95.6% versus 77.9%; p<0.001) than those with known COPD. Multivariate analysis demonstrated that airflow obstruction was an independent risk factor for lung cancer risk on baseline LDCT (adjusted OR 2.74, 95% CI 1.73-4.34; p<0.001), with a high risk seen in those with undiagnosed COPD (adjusted OR 2.79, 95% CI 1.67-4.64; p<0.001). Targeted case-finding within LCS detects high rates of undiagnosed symptomatic COPD in those most at risk. Individuals with undiagnosed COPD are at high risk for lung cancer.

Disease burden in individuals with symptomatic undiagnosed asthma or COPD

BackgroundThe actual burden of COPD and asthma may be much higher than appreciated, since a large proportion of individuals are not diagnosed. Our study objective was to compare health care utilization, burden of symptoms and quality of life in subjects with self-reported respiratory symptoms who were subsequently found to have undiagnosed airflow obstruction compared to those having no airflow obstruction. MethodsThis cross-sectional case-finding study used data from the Undiagnosed COPD and Asthma Population (UCAP) study. Adult subjects with respiratory symptoms who had no history of diagnosed lung disease were recruited in a two-step case-finding process using random digit-dialling of land lines and cell phones located within a 90-min radius of 16 Canadian study sites. Participants were assessed for COPD, asthma or no airflow obstruction using pre- and post-bronchodilator spirometry based on American Thoracic Society diagnostic criteria. Results1660 participants were recruited, of these 1615 had adequate spirometry and 331 (20.5%) subjects met spirometry criteria for undiagnosed asthma or COPD. Subjects with undiagnosed asthma or COPD had increased respiratory symptoms as assessed by the COPD Assessment Test (CAT), and higher St. George's Respiratory Questionnaire (SGRQ) scores indicating worse health-related quality of life, compared to subjects with no airflow obstruction. No between-group differences were found in health care utilization or work or school absenteeism. ConclusionUndiagnosed asthma and COPD are common in Canadian adults experiencing breathing problems and are associated with a greater burden of symptoms and poorer health-related quality of life. These results suggest that patients may benefit from early identification and treatment of undiagnosed asthma and COPD.

Derivation and validation of the UCAP-Q case-finding questionnaire to detect undiagnosed asthma and COPD.

Many people with asthma and COPD remain undiagnosed. We developed and validated a new case-finding questionnaire to identify symptomatic adults with undiagnosed obstructive lung disease. Adults in the community with no prior history of physician-diagnosed lung disease who self-reported respiratory symptoms were contacted via random-digit dialling. Pre- and post-bronchodilator spirometry was used to confirm asthma or COPD. Predictive questions were selected using multinomial logistic regression with backward elimination. Questionnaire performance was assessed using sensitivity, predictive values and area under the receiver operating characteristic curve (AUC). The questionnaire was assessed for test-retest reliability, acceptability and readability. External validation was prospectively conducted in an independent sample and predictive performance re-evaluated. A 13-item Undiagnosed COPD and Asthma Population Questionnaire (UCAP-Q) case-finding questionnaire to predict undiagnosed asthma or COPD was developed. The most appropriate risk cut-off was determined to be 6% for either disease. Applied to the derivation sample (n=1615), the questionnaire yielded a sensitivity of 92% for asthma and 97% for COPD; specificity of 17%; and an AUC of 0.69 (95% CI 0.64-0.74) for asthma and 0.82 (95% CI 0.78-0.86) for COPD. Prospective validation using an independent sample (n=471) showed sensitivities of 93% and 92% for asthma and COPD, respectively; specificity of 19%; with AUCs of 0.70 (95% CI 0.62-0.79) for asthma and 0.81 (95% CI 0.74-0.87) for COPD. AUCs for UCAP-Q were higher compared to AUCs for currently recommended case-finding questionnaires for asthma or COPD. The UCAP-Q demonstrated high sensitivities and AUCs for identifying undiagnosed asthma or COPD. A web-based calculator allows for easy calculation of risk probabilities for each disease.

Undiagnosed Chronic Obstructive Pulmonary Disease is Highly Prevalent in Patients Referred for Dobutamine Stress Echocardiography with Shortness of Breath.

Shortness of breath (SOB) is a common symptom referral for dobutamine stress echocardiography (DSE). Patients with SOB and a normal DSE have worse long-term outcome than the general population. This suggests multiple aetiologies are involved. The purpose of this study was to assess the prevalence and clinical significance of undiagnosed COPD amongst patients referred for a DSE with SOB. We prospectively studied 114 patients referred for DSE with SOB without prior evidence of lung disease (mean age 64.9 ± 18.5years, 60 male). Respiratory function testing using spirometry was performed on all patients on the day of their DSE. The study end-points were cardiac events and total mortality. Respiratory function testing and DSE was performed in all patients and COPD was highly prevalent (n = 93). Multivariate Cox regression analysis was used to estimate the effect of dyspnoea on non-fatal cardiac events (NFCE) and all-cause mortality. Over a mean follow-up of 4.5 ± 2.6years, the composite end-point of NFCE and all-cause mortality occurred in 62.7% and 16.7% patients, respectively. COPD (HR 1.27; 95% CI 1.17-1.93), previous myocardial infarction (HR 1.84; 95% CI 1.06-3.2), myocardial ischaemia (HR 2.56; 95% CI 1.48-4.43), peak wall motion score index (HR 4.66; 95% CI 2.26-9.6), and mitral E/E' (HR 1.21; 95% CI 1.1-1.33) were significantly associated with a NFCE. Myocardial ischaemia (HR 4.43; 95% CI 1.24-15.81) was the only independent predictor of all-cause mortality. Undiagnosed COPD is highly prevalent and independently associated with worse outcome amongst patients with SOB referred for DSE. Symptom presentation is therefore an important consideration when interpreting DSE results.

Disease Burden in Individuals with Symptomatic Undiagnosed Asthma or COPD

Disease Burden in Individuals with Symptomatic Undiagnosed Asthma or COPD

28 Diagnosed vs Undiagnosed Chronic Obstructive Pulmonary Disease: Short and Long-term Impact on Coronary Artery Bypass Surgery

Abstract Introduction This study sought to compare clinical outcomes among non-COPD, diagnosed COPD, and undiagnosed COPD patients, in CABG surgery. Method A single-centred retrospective study, from January 2010 to December 2019. Primary outcomes were post-operative complications, lenght of ITU admission and in-hospital staying. Secondary outcomes were re-intervention rate, in-hospital and long-term mortality. Results 4020 patients were divided into: non-COPD – Group A (74.55% n = 2997), diagnosed COPD – Group B (14.78% n = 594), and undiagnosed COPD – Group C (10.67% n = 429). The rate of respiratory complications was noted in this order: Group B &amp;gt; Group C &amp;gt; Group A (p 0.00000002). Perioperative Acute Kidney Injury, wound complications, and in-hospital staying were higher in Group B (p 0.0004, p 0.03, and p 0.0009, respectively). Long-term mortality resulted greater in Group B and C (p 0.0004). No difference in long-term mortality was noted in relation to the expected FEV1% in Group B (p 0.29) and Group C (p 0.82). Conclusions In CABG surgery, patients with diagnosed COPD carry a prolonged in-hospital staying and greater peri-operative complications. Both diagnosed and undiagnosed COPD predispose to respiratory complications and higher long-term mortality rate. Consequently, undiagnosed COPD should be included in the EuroSCORE. Finally, the expected FEV1% appears not to correlate with long-term survival.

Specialist respiratory outreach: a case-finding initiative for identifying undiagnosed COPD in primary care

COPD remains largely undiagnosed or is diagnosed late in the course of disease. We report findings of a specialist outreach programme to identify undiagnosed COPD in primary care. An electronic case-finding algorithm identified 1602 at-risk patients from 12 practices who were invited to attend the clinic. Three hundred and eighty-three (23.9%) responded and 288 were enrolled into the study. Forty-eight (16.6%) had undiagnosed mild and 28 (9.7%) had moderate airway obstruction, meeting spirometric diagnostic criteria for COPD. However, at 12 months only 8 suspected COPD patients (10.6%) had received a diagnostic label in their primary care record. This constituted 0.38% of the total patient population, as compared with 0.31% of control practices, p = 0.306. However, if all patients with airway obstruction received a coding of COPD, then the diagnosis rate in the intervention group would have risen by 0.84%. Despite the low take-up and diagnostic yield, this programme suggests that integrated case-finding strategies could improve COPD recognition.

Undiagnosed and Misdiagnosed Chronic Obstructive Pulmonary Disease: Data from the BOLD Australia Study.

PurposeSpirometry is necessary to confirm COPD, but many patients are diagnosed based on clinical presentation and/or chest x-ray. There are also those who do not present to primary care for case finding and remain undiagnosed. We aimed to identify: (a) factors that are associated with undiagnosed COPD; and (b) factors that are associated with a potential misdiagnosis of COPD.Patients and MethodsThis analysis used data from the Burden of Obstructive Lung Disease (BOLD), a cross-sectional study of community dwelling adults randomly selected from six study sites, chosen to provide a representative sample of the Australian population (n= 3357). Participants were grouped by COPD diagnostic criteria based on spirometry and self-reported diagnosis. Odds ratios for predictors of undiagnosed and misdiagnosed were estimated using logistic regression.ResultsOf the BOLD Australia sample, 1.8% had confirmed COPD, of whom only half self-reported a diagnosis of COPD. A further 6.9% probably had COPD, but were undiagnosed. The priority target population for case finding of undiagnosed COPD was aged ≥60 years (particularly those ≥75 years), with wheezing, shortness of breath and a body mass index (BMI) <25kg/m2. The priority target population for identifying and reviewing misdiagnosed COPD was aged <60 years, female, with no wheezing and a BMI ≥25kg/m2.ConclusionChallenges continue in accurately diagnosing COPD and greater efforts are needed to identify undiagnosed and misdiagnosed individuals to ensure an accurate diagnosis and the initiation of appropriate management in order to reduce the burden of COPD.

Short-term and long-term impact of diagnosed and undiagnosed chronic obstructive pulmonary disease on coronary artery bypass grafting surgery

ObjectivesThis study sought to compare clinical outcomes between three categories of patients: non-chronic obstructive pulmonary disease (COPD), diagnosed COPD and undiagnosed COPD in coronary artery bypass grafting surgery.MethodsA single-centred retrospective...

Screening for Undiagnosed COPD; Accuracy of Different Strategies Among Primary Care Patients in China: A Breathe Well Study

Background: Undiagnosed COPD is a major problem in China but the optimal screening strategy to identify new cases is unclear. Methods: Cross-sectional study in eight community health centres in four municipalities. Participants completed six index tests (screening questionnaires [CDQ, CAPTURE, Chinese Symptom-based questionnaire, COPD-SQ], microspirometry [COPD-6], peak flow [USPE]) and the reference test (ndd Easy On-PC spirometer). Cases were defined as those with FEV1/FVC below the lower limit of normal (LLN-GLI) on the reference test. Performance of individual screening tests and strategies was evaluated, with cost-effectiveness analyses providing cost per additional true case detected. Findings: 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. Airflow measurement devices (sensitivities 64.9% and 67.3%, specificities 89.7% and 82.6% for microspirometry and peak flow respectively) generally performed better than questionnaires, the most accurate of which was the Chinese symptom-based questionnaire (sensitivity 63.1% [95% CI 57.6%, 68.3%], specificity 74.2% [95% CI 72.3%, 76.1%]). The combination of Chinese Symptom-based questionnaire and microspirometry used in parallel maximised sensitivity (81.4%) and had specificity of 68%, with an incremental cost-effectiveness ratio of £64.20 (CNY385) per additional case detected compared with peak flow. Interpretation: Simple screening strategies to identify undiagnosed COPD within the primary care setting in China are possible, and a combination of the Chinese symptom-based questionnaire and microspirometry is the most sensitive. Further work is required to explore optimal cut-points. Trial Registration: The protocol for this study was previously published and registered on ISRCTN registry. The number was ISRCTN13357135 and the full study protocol can be accessed at http://www.isrctn.com (ISRCTN13357135). Funding Statement: This research was funded by the National Institute for Health Research (NIHR) NIHR global group on global COPD in primary care, University of Birmingham, (project reference: 16/137/95) using UK aid from the UK Government to support global health research. This paper presents independent research supported by the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: The study has been approved by Peking University First Hospital (2018-R-141, PUFH) and University of Birmingham (ERN_18-1177, UoB).

Prevalence and Characteristics of Undiagnosed COPD in Adults 40 Years and Older – Reports from the Tunisian Population-Based Burden of Obstructive Lung Disease Study

This study aimed to investigate the underdiagnosis of COPD and its determinants based on the Tunisian Burden of Obstructive Lung Disease study. We collected information on respiratory history symptoms and risk factors for COPD. Post-bronchodilator (Post-BD) FEV1/FVC < the lower limit of normal (LLN) was used to define COPD. Undiagnosed COPD was considered when participants had post-BD FEV1/FVC < LLN but were not given a diagnosis of emphysema, chronic bronchitis or COPD. 730 adults aged ⩾40 years selected from the general population were interviewed, 661 completed spirometry, 35 (5.3%) had COPD and 28 (80%) were undiagnosed with the highest prevalence in women (100%). When compared with patients with an established COPD diagnosis, undiagnosed subjects had a lower education level, milder airway obstruction (Post-BD FEV1 z-score −2.2 vs. −3.7, p < 0.001), fewer occurrence of wheezing (42.9% vs. 100%, p = 0.009), less previous lung function test (3.6% vs. 42.8%, p = 0.019) and less visits to the physician (32.1% vs. 85.7%, p = 0.020) in the past year. Multivaried analysis showed that the probability of COPD underdiagnosis was higher in subjects who had mild to moderate COPD and in those who did not visit a clinician and did not perform a spirometry in the last year. Collectively, our results highlight the need to improve the diagnosis of COPD in Tunisia. Wider use of spirometry should reduce the incidence of undiagnosed COPD. Spirometry should also predominately be performed not only in elderly male smokers but also in younger women in whom the prevalence of underdiagnosis is the highest.

Population-based case-finding to identify subjects with undiagnosed asthma or COPD.

∼5-10% of adults may have undiagnosed airflow obstruction. The objective of this study was to develop a population-based case-finding strategy to assess the prevalence of undiagnosed airflow obstruction (asthma or COPD) amongst adults with respiratory symptoms in Canada. Adults without a previous history of asthma, COPD or lung disease were recruited using random digit-dialling and asked if they had symptoms of dyspnoea, cough, sputum or wheeze within the past 6 months. Those who answered affirmatively completed the Asthma Screening Questionnaire (ASQ), COPD-Diagnostic Questionnaire (COPD-DQ) and COPD Assessment Test (CAT). Those with an ASQ score of ≥6 or a COPD-DQ score of ≥20 underwent pre- and post-bronchodilator spirometry to diagnose asthma or COPD. 12 117 individuals were contacted at home and assessed for study eligibility. Of the 1260 eligible individuals, 910 (72%) enrolled and underwent spirometry. Ultimately, 184 subjects (20% of those enrolled) had obstructive lung disease (73 asthma and 111 COPD). Individuals found to have undiagnosed asthma or COPD had more severe respiratory symptoms and impaired quality of life compared with those without airflow obstruction. The ASQ, COPD-DQ, and CAT had ROC areas for predicting undiagnosed asthma or COPD of 0.49, 0.64 and 0.56, respectively. Four descriptive variables (age, BMI, sex and pack-years smoked) produced better receiver operating characteristic (ROC) values than the questionnaires (ROC area=0.68). 20% of randomly selected individuals who report respiratory symptoms in Canada have undiagnosed airflow obstruction due to asthma or COPD. Questionnaires could exclude subjects at low risk but lack the ability to accurately find subjects with undiagnosed disease.

Impaired Sleep Quality in COPD Is Associated With Exacerbations: The CanCOLD Cohort Study

COPD increases susceptibility to sleep disturbances, which may in turn predispose to increased respiratory symptoms. The objective of this study was to evaluate, in a population-based sample, the relationship between subjective sleep quality and risk of COPD exacerbations. Data were obtained from the Canadian Cohort Obstructive Lung Disease (CanCOLD) study. Participants with COPD who had completed 18months of follow-up were included. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI) and a three-factor analysis. Symptom-based (dyspnea or sputum change ≥ 48 h) and event-based (symptoms plus medication or unscheduled health services use) exacerbations were assessed. Association of PSQI with exacerbation rate was assessed by using negative binomial regression. Exacerbation-free survival was also assessed. A total of 480 participants with COPD were studied, including 185 with one or more exacerbations during follow-up and 203 with poor baseline sleep quality (PSQI score > 5). Participants with subsequent symptom-based exacerbations had higher median baseline PSQI scores than those without (6.0 [interquartile range, 3.0-8.0] vs5.0 [interquartile range, 2.0-7.0]; P= .01), and they were more likely to have baseline PSQI scores > 5 (50.3%vs37.3%; P= .01). Higher PSQI scores were associated with increased symptom-based exacerbation risk (adjusted rate ratio, 1.09; 95%CI, 1.01-1.18; P= .02) and event-based exacerbation risk (adjusted rate ratio, 1.10; 95%CI, 1.00-1.21; P= .048). The association occurred mainly in those with undiagnosed COPD. Strongest associations were with Factor 3 (sleep disturbances and daytime dysfunction). Time to symptom-based exacerbation was shorter in participants with poor sleep quality (adjusted hazard ratio, 1.49; 95%CI, 1.09-2.03). Higher baseline PSQI scores were associated with increased risk of COPD exacerbation over 18months' prospective follow-up.