Diagnosis Of Obstructive Lung Disease Research Articles

Asthma diagnosis and treatment: Filling in the information gaps

Current approaches to the diagnosis and management of asthma are based on guideline recommendations, which have provided a framework for the efforts. Asthma, however, is emerging as a heterogeneous disease, and these features need to be considered in both the diagnosis and management of this disease in individual patients. These diverse or phenotypic features add complexity to the diagnosis of asthma, as well as attempts to achieve control with treatment. Although the diagnosis of asthma is often based on clinical information, it is important to pursue objective criteria as well, including an evaluation for reversibility of airflow obstruction and bronchial hyperresponsiveness, an area with new diagnostic approaches. Furthermore, there exist a number of treatment gaps (ie, exacerbations, step-down care, use of antibiotics, and severe disease) in which new direction is needed to improve care. Amajor morbidity in asthmatic patients occurs with exacerbations and in patients with severe disease. Novel approaches to treatment for these conditions will be an important advance to reduce the morbidity associated with asthma.

Are reference equations for spirometry an appropriate criterion for diagnosing disease and predicting prognosis?

In the last few years, there has been considerable debate on the use of threshold criteria for the diagnosis of obstructive lung disease based on FEV1 and FEV1/FVC ratio. It...

Population-Based Study on the Prevalence of Spirometric Obstructive Pattern in Porto, Portugal

The diagnosis of obstructive lung disease (OLD) based on clinical grounds is challenging. There have been no population-based COPD studies that collected pulmonary function data in Portugal, a country in transition between phases 2 and 3 of the smoking epidemic. To estimate the prevalence of obstructive pattern on spirometry in a representative sample of adults from Porto, Portugal. We conducted a health survey between 2001 and 2003, and 758 participants ≥ 40 years old had reliable spirometry. We used a structured questionnaire to collect demographic, clinical, social, and behavioral data. Obstructive pattern was defined as FEV(1)/FVC < 70%. Logistic regression was performed to quantify the association between socio-demographic and clinical factors and outcome. The participants' mean ± SD age was 58.5 ± 11.5 years, and 62% were women. The prevalence of spirometric obstructive pattern was 10.7%, 95% CI 8.6-13.1%; 13.4% in men, and 9.1% in women (P = .08). The age-adjusted odds ratios for cumulative smoking exposure of less than and more than 20 pack years, in comparison with never smokers, were 3.49 (95% CI 1.02-11.92) and 3.91 (95% CI 1.29-11.89) among men, and 1.47 (95% CI 0.53-4.08) and 2.68 (95% CI 1.07-6.68) among women, respectively. Previously diagnosed OLD was reported by 30.9% (95% CI 21.1-42.1%) of the participants with spirometric obstructive pattern. Spirometry confirmed the OLD diagnosis in 20.5% (95% CI 13.7-28.7%) of subjects who self-reported OLD (kappa = 0.14, 95% CI 0.07-0.20). The prevalence of spirometric obstructive pattern was high. Considering Portugal's position in the smoking epidemic, together with the aging of the population, we can expect an increase in the prevalence of OLD in older people and in women. Our results confirm the limited validity of self-reported OLD in epidemiological studies.

Differential diagnosis of obstructive lung diseases: asthma and COPD

Differential diagnosis of obstructive lung diseases: asthma and COPD

Early detection of COPD in general practice.

Background and aimEarly detection enables the possibility for interventions to reduce the future burden of COPD. The Danish National Board of Health recommends that individuals >35 years with tobacco/occupational exposure, and at least 1 respiratory symptom should be offered a spirometry to facilitate early detection of COPD. The aim, therefore, was to provide evidence for the feasibility and impact of doing spirometry in this target population.MethodsParticipating general practitioners (GPs) (n = 335; 10% of the Danish GPs) recruited consecutively, subjects with >35 years exposure, no previous diagnosis of obstructive lung disease, and at least 1 of the following symptoms: cough, dyspnea, wheezing, sputum, or recurrent respiratory infection. Data on age, smoking status, pack-years, body mass index (BMI), dyspnea score (Medical Research Council, MRC), and pre-bronchodilator spirometry (FEV1, FEV1% predicted, FEV1/FVC) were obtained.ResultsA total of 3.095 (51% females) subjects was included: mean age 58 years, BMI 26.3, and 31.5 pack-years. The majority of subjects (88%) reported MRC score 1 or 2. FEV1/FVC-ratio ≤ 0.7 was found in 34.8% of the subjects; the prevalence of airway obstruction increased with age and decreased with increasing BMI, and was higher in men and current smokers. According to the level of FEV1, 79% of the subjects with airway obstruction had mild to moderate COPD.ConclusionsMore than one-third of the recruited subjects had airway obstruction (FEV1/ FVC < 0.7). Early detection of COPD appears to be feasible through offering spirometry to adults with tobacco/occupational exposure and at least 1 respiratory symptom.

Diagnostic value of semi-volatile organic compounds in exhaled breath condensate of asthma and chronic obstructive pulmonary disease patients

Summary. Asthma and chronic obstructive pulmonary disease (COPD) can exhibit overlapping clinical features; therefore, diagnosis of these diseases can be difficult. Search of new biomarkers represents an active research field in modern respiratory medicine. The objective of this study was to investigate spectrum of semi-volatile organic compounds (SvOCs) in exhaled breath condensate (EBC) of healthy volunteers and patients with asthma and COPD and to assess the possibility for using these biomarkers in differential diagnosis of obstructive lung diseases. Seventy subjects participated in this cross-sectional study: 20 patients with exacerbation of COPD (age, 66.5 Ѓ} 8.5 years; FEV1, 57.3 Ѓ} 22.9 %pred), 20 patients with exacerbation of asthma (age, 50.2 Ѓ} 13.2 years; FEV1, 71.4 Ѓ} 20.7 %pred) and 30 healthy nonsmoking volunteers (age, 25.4 Ѓ} 9.6 years, FEV1, 98.4 Ѓ} 6.8 %pred). EBC was collected using ECoScreen equipment. Testing for SvOC of different polarity was conducted by gas chromatography/mass-spectrometry (GC / MS) method in EBC. The data collected were analyzed using an algorithm based on linear methods of pattern recognition theory. More than a hundred of SvOC in ultra-low concentrations were detected in EBC of the participants; 33 of SvOC were identified; 9 compounds (2.3-dihydro-1-H- inden-1-on, ethyl citrate, decanol-1.2-phenoxyethanol, etc.) had the highest informative value to differentiate the conditions. Mathematical analysis allowed distinguishing healthy volunteers from patients with asthma with reliability of 75 %, healthy subjects from COPD patients with reliability of 85 % and asthma patients from COPD patients with reliability of 83 %. In conclusion, we have developed a highly accurate GC-MS method to measure ultra-low concentrations of SvOC in EBC. This method can be used for diagnosis and differentiation of COPD and asthma.

Prevalence and risk factors for unrecognized obstructive lung disease among urban drug users

BackgroundObstructive lung disease (OLD) is frequently unrecognized and undertreated. Urban drug users are at higher risk for OLD due to race, behavioral, and socioeconomic characteristics, yet little data exist on prevalence and risk factors associated with unrecognized OLD in this population.ObjectiveThe objective of this study is to determine the prevalence of unrecognized OLD in an urban population and identify the characteristics associated with lack of physician-diagnosed OLD.DesignCross-sectional analysis from the Acquired Immunodeficiency Syndrome Linked to the Intravenous Experience (ALIVE) study, an observational study of current and former injection drug users in Baltimore, Maryland, USA.ParticipantsAll participants with spirometry-defined airflow obstruction were stratified by the presence or absence of physician diagnosis of OLD.Main measuresUsing cross-sectional demographic, clinical, and spirometric measurements, multivariable regression models were generated to identify factors independently associated with unrecognized OLD.Key resultsOf the 1083 participants evaluated in the ALIVE lung substudy, 176 (16.3%) met spirometric criteria for OLD. Of those, only 88 (50%) had a physician diagnosis of OLD. The prevalence of unrecognized OLD decreased as severity of airflow obstruction increased. Factors independently associated with unrecognized OLD were absence of respiratory symptoms (prevalence ratio [PR], 1.70; 95% confidence interval [CI]: 1.29–2.23; P < 0.01) and less severe dyspnea (PR, 0.83; 95% CI: 0.72–0.96, per point increase in dyspnea scale; P = 0.01). In the subset of human immunodeficiency virus (HIV)–infected participants, the use of antiretroviral therapy (ART) was independently associated with an increased prevalence of unrecognized OLD (PR, 1.93; 95% CI: 1.05–3.56; P = 0.03).ConclusionsIn a cohort of current and former urban drug users, OLD is substantially underrecognized and associated with lack of respiratory symptoms. Relying on the presence of respiratory symptoms as a trigger to perform spirometry may result in a substantial underdiagnosis of OLD in this population. HIV-infected individuals receiving ART are a population particularly vulnerable to unrecognized OLD.

O papel da razão FEF50%/0,5CVF no diagnóstico dos distúrbios ventilatórios obstrutivos

To evaluate the contribution of a new coefficient, the FEF50%/0.5FVC ratio, obtained from the maximal expiratory flow-volume curve, to the diagnosis of obstructive lung disease (OLD); to test this coefficient in differentiating among patients considered normal, those with OLD and those with restrictive lung disease (RLD); and to determine cut-off points for each functional diagnosis, as well as the probability for each diagnosis based on individual values. A prospective, cross-sectional study analyzing the pulmonary function of patients referred to the Porto Alegre Hospital de Clínicas, in Porto Alegre, Brazil, between January and December of 2003. We collected demographic and spirometric data. The patients were divided into three groups: normal; OLD; and RLD. We calculated the FEV1/FVC and FEF50%/0.5FVC ratios, and we compared the mean FEF50%/0.5FVC values among the groups. We used Pearson's correlation test in order to compare FEF50%/0.5FVC with FEV1/FVC. The patients were again divided into two groups: those with OLD and those without OLD. We calculated the likelihood ratio for different cut-off points. The mean age of the patients was 55.8 +/- 14.7 years. There were significant differences among the groups in terms of the mean FEF50%/0.5FVC (2.10 +/- 0.82, 2.55 +/- 1.47 and 0.56 +/- 0.29, respectively, for normal, RLD and OLD; p < 0.001). There was a positive correlation between FEF50%/0.5FVC and FEV1/FVC in the OLD group (r = 0.83). We found that an FEF50%/0.5FVC < 0.79 strongly suggests OLD, whereas an FEF50%/0.5FVC > 1.33 practically excludes this diagnosis. The FEF50%/0.5FVC ratio is a potentially useful parameter in the differential diagnosis of OLD and correlates positively with the FEV1/FVC ratio.

Effect on smoking quit rate of telling patients their lung age: the Step2quit randomised controlled trial

Objective To evaluate the impact of telling patients their estimated spirometric lung age as an incentive to quit smoking.Design Randomised controlled trial.Setting Five general practices in Hertfordshire, England.Participants 561 current...

FEV1/FVC Ratio of 70% Misclassifies Patients With Obstruction at the Extremes of Age

The American Thoracic Society recommends using the lower limit of normal (LLN) method to diagnose obstructive lung disease. However, few studies have investigated the clinical relevance of these recommendations. We compared the LLN derived from available data sets to a fixed ratio (FEV1/FVC, < 75% or 70%) and also to the FEV1/FVC percent predicted ratio to determine the impact of changing the FEV1/FVC "cutoff" on the spirometric diagnosis of obstructive lung disease. FEV1, FVC, FEV1/FVC ratio, age, race, sex, height, and weight were recorded from 1,503 pulmonary function tests. Predicted values were calculated using the Third National Health and Nutrition Examination Study data set (Hankinson), and reference values from studies by Crapo, Knudson, and Morris. In addition, the LLN of the FEV1/FVC ratio was calculated for the Hankinson and Crapo reference values. The number of studies interpreted as obstructed varied from 37% using the Hankinson data set to 55% using the 75% fixed ratio method. Comparing the LLN method vs the 70% fixed ratio method resulted in 7.5% (Hankinson LLN vs 70% fixed) and 6.9% (Crapo LLN vs 70% fixed), which were discordant results. Age was the strongest predictor of discordance, and 16% of subjects > 74 years of age had discordant results comparing Hankinson values to the 70% fixed method. At the extremes of age and height, a large number of spirometry test results will be interpreted as showing an obstructive defect if a 70% fixed ratio method is used for interpretation compared with the LLN derived from the Hankinson data set.

Symptom-Based Questionnaire for Differentiating COPD and Asthma

Background: Many patients with obstructive lung disease (OLD) carry an inaccurate diagnostic label. Symptom-based questionnaires could identify persons likely to need spirometry. Objectives: We prospectively tested questions derived from a comprehensive literature review and an international Delphi panel to help identify chronic OLD (COPD) in persons with prior evidence of OLD. Methods: Subjects were recruited via random mailing to primary-care practices in Aberdeen, Scotland, and Denver, Colorado. Persons aged 40 and older reporting any prior diagnosis of OLD or any respiratory medications in the past year were enrolled. Participants answered 54 questions covering demographics and symptoms and underwent spirometry with reversibility testing. A study diagnosis of COPD was defined by fixed airway obstruction as measured by post-bronchodilator FEV₁/FVC <0.70. We examined ability of individual questions in a multivariate framework to discriminate between persons with and without the study diagnosis of COPD. Results: 597 persons completed all investigations and proceeded to analysis. The list of 54 questions yielded 52 items for analyses, which was reduced to 19 items for entry into a multivariate regression model. Nine items had significant relationships with the study diagnosis of COPD, including increased age, pack-years, worsening cough, breathing-related disability or hospitalization, worsening dyspnea, phlegm quantity, cold going to the chest, and receipt of treatment for breathing. Individual items yielded odds ratios ranging from 0.33 to 20.7. This questionnaire demonstrated a sensitivity of 72.0 and a specificity of 82.7. Conclusions: A short, symptom-based questionnaire identifies persons more likely to have COPD among persons with prior evidence of OLD.

Misdiagnosis of COPD and Asthma in Primary Care Patients 40 Years of Age and Over

Chronic obstructive pulmonary disease (COPD) is often misdiagnosed as asthma, leading to inappropriate treatment and suboptimal patient outcomes. As part of a prospective study of patients with a history consistent with obstructive lung disease, we compared prior diagnostic labels with a study diagnosis based on spirometric results. We enrolled persons 40 years of age or older with prior diagnoses or medications consistent with obstructive lung disease. Patients were recruited via random mailing to primary care practices in Aberdeen, Scotland, and Denver, Colorado. Prior diagnoses of chronic bronchitis or emphysema (CBE) and asthma were reported by the subjects. Participants underwent pre- and post-bronchodilator spirometry. A study diagnosis of COPD was defined using post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) < 0.70. Spirometric examination was complete in 597 patients, of whom 235 (39.4%) had a study diagnosis of COPD. Among subjects with a spirometry-based study diagnosis of COPD, 121 (51.5%) reported a prior diagnosis of asthma without concurrent CBE diagnosis, 89 (37.9%) reported a prior diagnosis of CBE, and 25 (10.6%) reported no prior diagnosis of obstructive lung disease. Despite the availability of consensus guideline diagnostic recommendations, diagnostic confusion between COPD and asthma appears common. Increased awareness of the differences between the two conditions is needed to promote optimal patient management and treatment.

Is it asthma or COPD?

PREVIEWEvaluation and diagnosis of obstructive lung disease call for careful history taking to distinguish asthma from chronic obstructive pulmonary disease (COPD). A history of atopy and intermittent, reactive symptoms points toward a diagnosis of asthma, whereas smoking and advanced age are more indicative of COPD. Clinical features such as cough and wheezing, especially in light of patient history, can be suggestive but are not definitive. Spirometry, usually performed in the primary care setting, is the key diagnostic tool that distinguishes patients with asthma from patients with COPD. In this article, the authors outline an approach to differential diagnosis of asthma and COPD that should result in better evaluation, therapy, and quality of life for these patients.

Development of a Population-Based Screening Questionnaire for COPD

COPD is commonly under-diagnosed, in part because people at risk are unaware of the relevant risk factors and do not recognize related symptoms. Providing this information might permit earlier disease identification but the questions chosen should identify those with spirometrically defined airflow obstruction. Using a population-based data set, we have determined which questions identify persons most likely to have airflow obstruction. Potential questions were selected by review of COPD risk factors and clinical features. Validation was by retrospective analysis of the NHANES III data set, a population-based U.S. household survey that included spirometry. We examined the predictive ability of individual questions in a multi-variate framework to correctly discriminate between persons with and without spirometric airway obstruction (defined as FEV1/FVC < 0.70). We then tested the discriminatory ability of the questions in combination. The following items showed significant predictive ability: increased age, smoking status, pack-years, cough, wheeze, and prior diagnosis of asthma or COPD. The best performing combination was age, smoking status, pack-years smoked, wheeze, phlegm, body mass index, and prior diagnosis of obstructive lung disease. Using this combination in a population of current and former smokers aged 40 and over, we achieved a sensitivity of 85% and specificity of 45%, with a positive predictive value of 38% and a negative predictive value of 88%. Performance of this tool is comparable to other screening methods designed for use in a general population. Symptom-based questionnaires can be a viable method to identify persons likely to have COPD in the general population. Dissemination of such tools should raise awareness among at-risk persons and help identify COPD patients in the primary care setting.

Airway Obstruction Is Common but Unsuspected in Patients Admitted to a General Medicine Service

Obstructive lung disease (OLD) is a worldwide health problem with major impact on health and economics, and can be easily diagnosed by spirometry. Recent expert panels have emphasized the underreporting and underrecognition of this condition. The goal of this study was to measure the prevalence of airway obstruction in patients admitted to an urban teaching hospital and to determine the frequency of a diagnosis of OLD at admission or discharge. Prospective study of 153 patients admitted to a medicine service at the Johns Hopkins Hospital in Baltimore, MD. Patients completed bedside spirometry and a questionnaire. Twenty-six percent of patients had airway obstruction (FEV(1)/FVC < 70%), including 6% with a very severe airway obstruction (FEV(1) < 30% predicted). At hospital discharge, a clinical diagnosis of OLD was present in only 33% of patients with mild airway obstruction (FEV(1) > 70% predicted), 30% of patients with moderate airway obstruction (FEV(1) 50 to 69% predicted), 33% of patients with severe airway obstruction (FEV(1) 30 to 49% predicted), and 89% of patients with very severe airway obstruction (FEV(1) < 30% predicted). Only 40% of patients with airway obstruction were receiving bronchodilator medication at hospital admission or discharge. Airway obstruction is common in hospitalized patients and is usually undiagnosed and untreated. Spirometry may be a useful component of the examination of hospitalized medical patients to identify OLD.

Enfermedad pulmonar obstructiva tras trasplante alogénico de progenitores hematopoyéticos en niños

Bronchiolitis obliterans is recognized as a life-threatening pulmonary complication that can develop 3 months after bone marrow transplantation. To determine the incidence and clinical progression of obstructive lung disease (OLD) in a population of children who had undergone allogenic hematopoietic stem cell transplantation (HSCT). We examined a sequential sample of 110 patients who received allogeneic HSCT between January 1992 and June 2002. The incidence of OLD in the 77 children who survived for more than 100 days after transplantation was analyzed. The diagnosis of OLD was based on clinical findings with no evidence of infection, pulmonary function test (FEV1/FVC less than 80 % and FEV1 less than 80 % of predicted value) and computed tomography scan. Eight patients (10.4 %) developed OLD at a median time of onset of 184 days after allogenic HSCT (range: 100-1735 days). All patients with OLD had respiratory symptoms. In six out of eight patients airflow obstruction was diagnosed within 1 year of transplantation. All patients showed chronic graft-versus-host disease (GVHD) (p < 0.01). The incidence of OLD in the 23 patients with chronic GVHD was 34.8 %. Two patients (25 %) had a complete response to intensified treatment of chronic GVHD with immunosuppressant therapy. FEV1 declined rapidly in three patients (37.5 %) who died of respiratory failure. Two patients (25 %) had partial reversal but pulmonary function continued below normal values. In one patient (12.5 %) severe obstructive disease was stable. The time of onset and form of progression of OLD after HSCT may vary. OLD is strongly associated with chronic GVHD and its incidence depends on the number of patients with chronic GVHD.

Cigarette Smoking-Attributable Morbidity

Cigarette Smoking-Attributable Morbidity

Diagostic value of respiratory impedance measurements in elderly subjects

Obstructive lung disease (OLD) is highly prevalent in elderly subjects but markedly under-diagnosed. Indeed, only 40–50% of hospitalized elderly patients are able to adequately perform spirometric tests. This study aimed to evaluate, in an acute-care geriatric hospital, the diagnostic value of measuring airway impedance (Zrs) by the forced oscillation technique (FOT) for: (1) identifying OLD and (2) identifying responders vs. non-responders to bronchodilators.Sixty-seven patients (aged 82±8 years) underwent consecutive measurement of Zrsand forced expiratory volumes before and after bronchodilators. Zrswas measured by FOT at frequencies of 4–30 Hz. Correlations, ROC curves and logistic regression models were established to determine the sensitivity (Se) and specificity (Sp) of Zrsin identifying OLD.Significant correlations were found between spirometric and Zrsmeasurements. The Zrsparameters yielding the best Se and Sp for detecting OLD were: Fn (resonant frequency; Se: 76%; Sp: 78%) and R0(resistance extrapolated for a frequency of 0: Se: 76%; Sp: 74%). Using the logistic regression models, 76% of the patients were correctly classified as having OLD or not. Zrswas however not contributive in identifying responders to bronchodilators.Zrsmeasurements by FOT are contributive to the diagnosis of OLD in elderly hospitalized patients.

Obstructive lung disease and low lung function in adults in the United States: data from the National Health and Nutrition Examination Survey, 1988-1994.

Obstructive lung disease (OLD) is an important cause of morbidity and mortality in the US adult population. Potentially treatable mild cases of OLD often go undetected. This analysis determines the national estimates of reported OLD and low lung function in the US adult population. We examined data from the Third National Health and Nutrition Examination Survey (NHANES III), a multistage probability representative sample of the US population. A total of 20,050 US adults participated in NHANES III from 1988 to 1994. Our main outcome measures were low lung function (a condition determined to be present if the forced expiratory volume in 1 second-forced vital capacity ratio was less than 0.7 and the forced expiratory volume in 1 second was less than 80% of the predicted value), a physician diagnosis of OLD (chronic bronchitis, asthma, or emphysema), and respiratory symptoms. Overall a mean (SE) of 6.8% (0.3%) of the population had low lung function, and 8.5% (0.3%) of the population reported OLD. Obstructive lung disease (age-adjusted to study population) was currently reported among 12.5% (0.7%) of current smokers, 9.4% (0.6%) of former smokers, 3.1% (1.1%) of pipe or cigar smokers, and 5.8% (0.4%) of never smokers. Surprisingly, 63.3% (0.2%) of the subjects with documented low lung function had no prior or current reported diagnosis of any OLD. This study demonstrates that OLD is present in a substantive number of US adults. In addition, many US adults have low lung function but no reported OLD diagnosis, which may indicate the presence of undiagnosed lung disease.

OBSTRUCTIVE PULMONARY DISEASE: The Clinician's Perspective

This article reviews the differential diagnosis of obstructive lung disease, including lesions that may mimic chronic obstructive pulmonary disease, as well as the tools on which the clinician relies for making a proper diagnosis. The clinician's view of the radiologist's role is briefly discussed, but the details of specific radiologic techniques are discussed elsewhere in this issue.