Undiagnosed Airflow Obstruction Research Articles

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.

Prevalence of abnormal spirometry in individuals with a smoking history and no known obstructive lung disease

IntroductionRecent evidence suggests a high prevalence of undiagnosed chronic obstructive pulmonary disease (COPD). These individuals are at risk of exacerbations and delayed treatment. We analyzed an at-risk population for the prevalence of abnormal spirometry to provide clarity into who should undergo early spirometry. MethodsWe analyzed data from the COPDGene study. Participants with ≥10 pack-years of smoking were included. Individuals with self-reported or physician-diagnosed COPD, asthma, chronic bronchitis, emphysema and/or were on inhalers were excluded. Parsimonious multivariable logistic regression models identified factors associated with abnormal spirometry, defined as either airflow obstruction (AFO) or preserved ratio impaired spirometry. Variables were selected for the final model using a stepwise backward variable elimination process which minimized Akaike information criterion (AIC). Similarly, during the 5-year follow-up period, we assessed factors associated with incident diagnosis of COPD. ResultsOf 5055 individuals, 1064 (21%) had undiagnosed AFO. Age, pack-years, current smoking and a history of acute bronchitis were associated with AFO while body mass index, female sex, and Black race were inversely associated. Among 2800 participants with 5-year follow-up, 532 (19%) had an incident diagnosis of COPD. Associated risk factors included mMRC ≥2, chronic productive cough, respiratory exacerbations during the follow-up period, and abnormal spirometry. Age was inversely associated. ConclusionsThe prevalence of undiagnosed COPD is high in at-risk populations. We found multiple factors associated with undiagnosed COPD and incident diagnosis of COPD at follow up. These results can be used to identify those at risk for undiagnosed COPD to facilitate earlier diagnosis and treatment.

Prevalence of asymptomatic airflow obstruction among patients visiting a tertiary health-care center

Background: Chronic obstructive lung disease is a major health problem worldwide, with a huge impact on health and economics, both at the individual and community levels. In clinical practice, only symptomatic patients seem to undergo spirometry screening, whereas persons with no symptoms or those with early or negligible symptoms are ignored until they present with acute exacerbations and complications. Fair evidence indicates that most individuals with airflow obstruction do not recognize or report symptoms. Aims and Objectives: The present study was conducted to identify the prevalence of undiagnosed airflow obstruction in asymptomatic adults, without known obstructive lung disease or any other pulmonary condition. Materials and Methods: A total of 500 subjects between 18 and 65 years of age, coming to the outpatient department for a routine/preventive health checkup who wereasymptomatic and never diagnosed for airflow obstruction, with no evidence of any physical disease on examination were selected by random sampling method after taking informed written consent. A detailed history, complete general physical and clinical examination, and spirometry (as per the ATS guidelines) for individuals were done. Results: Overall prevalence of AO was 16% of patients (80 patients out of 500). About 4.20% of patients had mild obstruction (GOLD – Stage 1), 4.60% had moderate obstruction (GOLD – Stage 2), 5.40% had severe obstruction (GOLD – Stage 3), and 1.80% had very severe obstruction (GOLD – Stage 4). Subjects with asymptomatic airflow obstruction had a higher prevalence of ever smoking (72.5%, 58 out of 80 patients) than never smokers (27.5%, 22 out of 80 patients) and this difference was highly significant statistically. Conclusion: There is a high prevalence of asymptomatic airflow obstruction, detected by spirometry, in asymptomatic patients of different severities. Smoking is a strong risk factor and AO is directly associated with age, both among smokers and never smokers. The use of spirometry should be implemented in all routine health checkup plans, as an important diagnostic tool.

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.

Early Detection of COPD: An Opportunistic Case Finding Study in Smokers and Ex-Smokers Visiting a Medical Centre.

BackgroundDifferent case finding approaches have been used to identify early COPD. The objective of this study was to assess the feasibility and the yield of opportunistic early COPD case finding in visitors to a large medical centre.Patients and MethodsFrom May 2014 to June 2017, we consecutively recruited adults aged ≥ 18 years visiting the Shaare Zedek Medical Center, in Jerusalem. Our 3-step intervention included: a) pre-screening for symptoms with the 5-item “Could it be COPD?” questionnaire (score= 0–5 pts); b) pre-BD spirometry; and c) referral to a caregiver. Airflow obstruction was defined by a FEV1/FVC < 0.7. Spirometry results were used as an incentive to promote smoking cessation and quit rates were verified by phone survey 3 months after the intervention.ResultsA total of 1001 subjects (956 smokers; 45 ex-smokers) were recruited. Mean (SD) age was 48.3 years (13.5). Airflow obstruction was detected in 180 (18%) subjects of whom 142 (78.9%) were unaware of it, including 27 subjects with severe (50% ≥ FEV1 ≤ 30% predicted) (n=25) or very severe (FEV1 < 30% predicted) (n=2) obstruction. Multiple logistic regression analysis found that age, BMI, cigarette smoking (p.y.) and a “Could it be COPD?” questionnaire score ≥ 3 points correctly classified 83.3% of cases of airflow obstruction. At follow-up, 54.5% of participants reported smoking as usual, 30.9% reduced smoking [mean (SD) = 10.1 ± 7.8 cigarettes/day], 7.4% increased smoking [mean (SD) = 9.2 ± 6.3 cigarettes/day] and 7.2% claimed smoking cessation. Among obstructed subjects, 38.7% had visited a physician because of COPD, while 20.7% were taking a new respiratory medication.ConclusionEarly COPD case finding was feasible and effective in identifying undiagnosed airflow obstruction among visitors to a medical centre. Smoking cessation counselling based on spirometry promoted a small but clinically meaningful cessation rate.

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.

Prevalence, Awareness, and Associated Factors of Airflow Obstruction in Russia: The Ural Eye and Medical Study.

Background: Although chronic obstructive pulmonary disease and asthma belong to the most important causes of disability and death in all world regions, data about the prevalence of airflow obstruction and asthma in Russia and the associated parameters have been scarce so far. We therefore assessed the prevalence of airflow obstruction and asthma in a Russian population.Methods: The population-based Ural Eye and Medical Study, conducted in a rural and urban region of Bashkortostan/Russia, included 5,392 participants (mean age: 58.6 ± 10.6 years; range: 40–94 years) out of 7,328 eligible individuals. Airflow obstruction was defined spirometrically and asthma by self-reported diagnosis.Results: Airflow obstruction was present in 369 individuals (6.8%; 95% confidence interval (CI): 6.2, 7.5) with an awareness rate of 63.4% (95%CI: 58.5, 68.4) and known duration of 19.5 ± 15.8 years (median: 16 years). Prevalence of undiagnosed airflow obstruction was 2.6% (95%CI: 2.2, 3.1). Higher prevalence of airflow obstruction was associated (multivariable analysis) with higher prevalence of current smoking [P < 0.001; odds ratio (OR): 2.91; 95%CI: 1.76, 4.83] and number of cigarette package years (P < 0.001; OR: 1.03; 95%CI: 1.02, 1.08), female gender (P = 0.03; OR: 1.42; 95%CI: 1.04, 1.93), urban region (P = 0.003; OR: 1.43; 95% CI: 1.12, 1.79), higher prevalence of cardiovascular diseases/stroke (P < 0.001; OR: 1.86; 95%CI: 1.45, 2.39), higher depression score (P = 0.002; OR: 1.05; 95%CI: 1.02, 1.08), and lower physical activity (P = 0.01; OR: 0.71; 95%CI: 0.54, 0.93). Asthma prevalence (2.6%; 95%CI: 2.0, 3.1; known duration: 17.2 ± 15.0 years) was associated with less alcohol consumption (OR: 0.53; 95%CI: 0.33, 0.87; P = 0.01), higher depression score (OR: 1.08; 95%CI: 1.03, 1.12; P < 0.001), and urban region (OR: 0.68; 95CI: 0.49, 0.95; P = 0.0.03).Conclusions: In this Russian population aged 40+ years, the prevalence of airflow obstruction was 6.8% with an awareness rate of 63.4% and smoking as main risk factor. Asthma prevalence was 2.6%.

Prevalence of undiagnosed airflow obstruction among people with a history of smoking in a primary care setting.

PurposeThe purpose of this study was to define the prevalence of undiagnosed airflow obstruction (AO) among subjects with a history of smoking but no previous diagnosis of chronic lung disease. The finding of AO likely represents diagnosis of chronic obstructive pulmonary disease.PatientsPeople aged ≥30 years with a history of smoking who attended public outpatient clinics for primary care services were included in this study.MethodsA cross-sectional survey in five clinics in Hong Kong using the Breathlessness, Cough, and Sputum Scale, the Lung Function Questionnaire, and office spirometry was conducted.ResultsIn total, 731 subjects (response rate =97.9%) completed the questionnaires and spirometry tests. Most of the subjects were men (92.5%) in the older age group (mean age =62.2 years; standard deviation =11.7). Of the 731 subjects, 107 had AO, giving a prevalence of 14.6% (95% confidence interval =12.1–17.2); 45 subjects with AO underwent a postbronchodilator test. By classifying the severity of chronic obstructive pulmonary disease using the Global Initiative for Chronic Obstructive Lung Disease, 27 (60%) were considered to be in mild category and 18 (40%) in moderate category. None of them belonged to the severe or very severe category. The total score of Lung Function Questionnaire showed that majority of the subjects with AO also had chronic cough, wheezing attack, or breathlessness, although most did not show any acute respiratory symptoms in accordance with the Breathlessness, Cough, and Sputum Scale. Diagnosis of AO was positively associated with the number of years of smoking (odds ratio =1.044, P=0.035) and being normal or underweight (odds ratio =1.605, P=0.046). It was negatively associated with a history of hypertension (odds ratio =0.491, P=0.003).ConclusionOne-seventh of smokers have undiagnosed AO. Spirometry screening of smokers should be considered in order to diagnose AO at an early stage, with an emphasis on smoking cessation.

Undiagnosed airflow limitation is common in patients with coronary artery disease and associated with cardiac stress

Smoking is a common risk factor for coronary artery disease (CAD) and chronic obstructive pulmonary disease (COPD). We evaluated the prevalence of undiagnosed COPD in patients with CAD and assessed the relationship between airflow obstruction and markers of cardiac stress. We recruited prospectively consecutive patients aged >40 years without known history of chronic lung disease (e.g. asthma, COPD, bronchiectasis) who had undergone percutaneous coronary intervention (PCI) for obstructive CAD between August 2009 and October 2010. Spirometry was performed and serum ST2, a novel biomarker of cardiomyocyte stress and fibrosis, was measured by enzyme-linked immunosorbent assay. Among 475 subjects (mean age 64 ± 9.7, range 42-85 years, 87.2% males, 58.5% current or ex-smokers) who underwent spirometry, 51 (10.7%) had undiagnosed airflow obstruction with FEV1 /FVC ratio <70%. Of these 51 subjects, 14 (2.9%), 23 (4.8%) and 14 (2.9%) had FEV1 ≥80, 50-80 and 30-50% predicted normal, respectively. ST2 level was measured in all the subjects with undiagnosed airflow obstruction and in 290 subjects with normal lung function. There was no significant difference in left ventricular ejection fraction on echocardiogram between subjects with and without airflow obstruction. Patients with severe airflow obstruction had a higher level of cardiac stress marker ST2 than those with mild and moderate airflow obstruction (rho = -0.214, P ≤ 0.001). Undiagnosed airflow obstruction is common among patients with CAD who have undergone PCI. Severity of airflow limitation is associated with increasing cardiac stress.

Implementation of a targeted screening program to detect airflow obstruction suggestive of chronic obstructive pulmonary disease within a presurgical screening clinic.

Targeted spirometry screening for chronic obstructive pulmonary disease (COPD) has been studied in primary care and community settings. Limitations regarding availability and quality of testing remain. A targeted spirometry screening program was implemented within a presurgical screening (PSS) clinic to detect undiagnosed airways disease and identify patients with COPD/asthma in need of treatment optimization. The present quality assurance study evaluated airflow obstruction detection rates and examined characteristics of patients identified through the targeted screening program. The targeted spirometry screening program was implemented within the PSS clinic of a tertiary care university hospital. Current or ex-smokers with respiratory symptoms and patients with a history of COPD or asthma underwent prebronchodilator spirometry. History of airways disease and smoking status were obtained during the PSS assessment and confirmed through chart reviews. After exclusions, the study sample included 449 current or ex-smokers. Abnormal spirometry results were found in 184 (41%) patients: 73 (16%) had mild, 93 (21%) had moderate and 18 (4%) had severe or very severe airflow obstruction. One hundred eighteen (26%) new cases of airflow obstruction suggestive of COPD were detected. One-half of these new cases had moderate or severe airflow obstruction. Only 34% of patients with abnormal spirometry results had reported a previous diagnosis of COPD. More than one-half of patients with abnormal spirometry results were current smokers. Undiagnosed airflow obstruction was detected in a significant number of smokers and ex-smokers through a targeted screening program within a PSS clinic. These patients can be referred for early intervention and secondary preventive strategies.

Healthcare for Obstructive Lung Disease in an Industrial Spirometry Surveillance Program

The efficacy of workplace spirometry surveillance programs is unclear. We examine whether aluminum industry workers with airflow obstruction (AO) received health care for obstructive lung disease. We performed a cross sectional analysis over 7 years of 6821 aluminum production workers. The primary outcome was the association between obstructive lung disease insurance claims and the presence of AO. We also examined whether the presence of claims was associated with increasing AO severity. Although workers with AO more frequently had claims, 60% of workers with AO, most frequently those with mild and borderline obstruction, had no claim. Workers with AO, particularly borderline and mild obstruction, frequently do not receive health care despite respiratory surveillance. Further investigation is needed to determine if workers with undiagnosed AO are symptomatic or have accelerated losses in lung function over time.

Variability of the Prevalence of Undiagnosed Airflow Obstruction in Smokers Using Different Diagnostic Criteria

To estimate the prevalence of undiagnosed airflow obstruction (AFO) in Hong Kong smokers with no previous diagnosis of respiratory disease, and to assess its variability when applying different prediction equations and diagnostic criteria. A multicenter, population-based, cross-sectional prevalence study was performed in smokers aged 20 to 80 years. Three different criteria (fixed 70% [Global Initiative for Chronic Obstructive Lung Disease and British Thoracic Society], fixed 75%, and European Respiratory Society [ERS]) were applied to define a lower limit of normal (LLN) of the FEV(1)/FVC ratio to compare with the Hong Kong Chinese reference equation (criterion 1), which had used a distribution-free method to obtain the lower fifth percentile of FEV(1)/FVC ratio as the LLN. In 525 male patients, using criterion 1 (local internal prediction equation) and defining AFO as FEV(1)/FVC less than LLN, the overall prevalence of AFO was 13.7%: 8.3% in age > or = 20 to 40 years, 14.0% in age > or = 40 to 60 years, and 17.8% in age > or = 60 to 80 years. When the local internal prediction equation was used as the comparison reference, the fixed-ratio methods tended to miss AFO in younger age groups and overdiagnose AFO in old age, while the ERS criteria, which uses an almost lower fifth percentile-equivalent method, showed less of such a trend but still only showed moderate agreement with criterion 1. Undiagnosed AFO was prevalent in Hong Kong smokers. Estimated prevalence rates were highly affected by the criteria used to define AFO. The predicted lower fifth percentile values calculated from a local reference equation as the LLN of FEV(1)/FVC ratio should be used for the diagnosis of AFO.

Respiratory Symptoms and Undiagnosed Airflow Obstruction in Middle-Aged Adults: The Korean Health and Genome Study

The prevalence of undiagnosed airflow obstruction is difficult to measure since it requires screening in population-based samples to identify individuals free of clinical symptoms. The purpose of this report is to examine the prevalence of undiagnosed airflow obstruction and its relation with respiratory symptoms in middle-age adults in the Korean Health and Genome (KHG) Study. The KHG study is an ongoing population-based study of Korean adults aged 40 to 69 years. The current report includes 8,140 men and women without a pulmonary disorder or obstructive lung disease. In this sample, undiagnosed airflow obstruction was defined on the basis of spirometric testing and in the absence of a medical history or a recognized pulmonary disorder. Respiratory symptoms included chronic cough, chronic phlegm, wheezing, and shortness of breath. Undiagnosed airflow obstruction was observed in 12.4% of the men (470 of 3,806 subjects) and in 3.5% of the women (152 of 4,334 subjects). In men, the age-adjusted prevalence of undiagnosed airflow obstruction increased consistently with increasing number of respiratory symptoms. In those who smoked, there was a 2.3-fold excess in its prevalence when three or more symptoms were present, as compared to when they were absent (27.4% vs 12.0%, p < 0.001). A 2.4-fold excess (20.6% vs 8.5%, p = 0.004) was observed in nonsmoking men, in whom respiratory symptoms were consistently less common than in those who smoked. Respiratory symptoms were unrelated to undiagnosed airflow obstruction in women smokers, although only 3.9% smoked cigarettes. In women who were nonsmokers, the prevalence of undiagnosed airflow obstruction increased from 2.3% in those without a respiratory symptom to 6.0% when three or more symptoms were present (p = 0.003). Findings suggest that undiagnosed airflow obstruction is common in Korea with several respiratory symptoms. Whether respiratory symptoms with associations with undiagnosed airflow obstruction can be used to design early intervention strategies that prevent or delay the onset of COPD and its disabling consequences warrants further study.

Undiagnosed airflow obstruction: prevalence and implications.

Conditions associated with airflow obstruction are often over- and underdiagnosed. Prevalence estimates of undiagnosed airflow obstruction (UDAO) range from 3 to 12%. UDAO is a nonspecific physiologic abnormality that may be caused by a number of factors (eg, cigarette smoking) and can be the manifestation of many different disorders. The higher occurrence of UDAO among men, current or former smokers, and with advancing age provide preliminary evidence on probable causes and diagnoses (ie, chronic obstructive pulmonary disease). While cigarette smoking is associated with UDAO, a substantial proportion of persons have never smoked, particularly among women. Few studies suggest that this condition is associated with increased morbidity and mortality. While there is currently no evidence to support screening for UDAO, case-finding may have a role among persons with respiratory symptoms, who have ever smoked, with a family history of respiratory disease, or with occupational exposures to dusts or fumes.

The health impact of undiagnosed airflow obstruction in a national sample of United States adults.

To determine the health and functional impact of undiagnosed airflow obstruction for subjects in the general population, we used data obtained as part of the Third National Health and Nutrition Examination Survey (NHANES III). Categories of diagnosed and undiagnosed airflow obstruction were defined using questionnaire responses and spirometric results. Health and functional impact of airflow obstruction was assessed from responses to questions about general health status, walking 1/4 mile, lifting or carrying something as heavy as 10 lb, or needing help with personal care. Undiagnosed airflow obstruction (12.0%) was more common than doctor-diagnosed chronic obstructive pulmonary disease (COPD) (3.1%) or asthma (2.7%). Although undiagnosed airflow obstruction was usually very mild, approximately 5% of the entire sample had an FEV(1) less than 75% predicted. After adjusting for smoking, obesity, and comorbid conditions, the risk of impaired health and functional status with undiagnosed airflow obstruction was independently associated with severity of FEV(1) impairment. For males and females, ever smoking was strongly associated with all types of airflow obstruction, diagnosed or not. However, among females with airflow obstruction, 12.2% to 35.2% never smoked. Undiagnosed airflow obstruction is common in the general population of the United States and is associated with impaired health and functional status. airflow obstruction; spirometry; health impact; screening