Peak Expiratory Flow Measurements Research Articles

A randomized trial of the efficacy of interventions in improving indoor air quality and health in children with asthma: final results

Introduction: We tested the efficacy of two in-home interventions in improving asthma symptoms in children living in homes using wood stoves for heating and investigated evidence that improvements in health occur by way of PM2.5 reductions. Methods: We recruited 98 homes in western Montana, Idaho, and Alaska, and randomly assigned each to a new wood stove, an active air filtration unit, or a placebo filtration unit. During two consecutive winter periods, we evaluated changes in asthma-related health using the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) and pulmonary function measures (peak expiratory flow; forced expiratory flow in the first second; and diurnal peak flow variability, dPFV) using a PiKo-1 meter (Ferraris). We also measured 48-hour average indoor PM2.5 and coarse PM (PM10-2.5) concentrations using a DustTrak (TSI) and particle counter (Lighthouse), respectively. We used linear mixed models to investigate the dependence on treatment assignment of pre- to post-intervention PAQLQ and pulmonary function changes. In dose-response analyses, we evaluated the impact of PM2.5 and PM10-2.5 on PAQLQ scores and pulmonary function. Results: Relative to placebo, the wood stove arm had no impact on PM2.5 or asthma measures. In contrast, the active air filter arm was associated significantly with both lower PM2.5 and improved dPFV (4.2 percentage point greater reduction, 95% CI: -7.9, -0.5). The magnitude of this improvement was greatest in children with the most severe asthma at baseline. Dose-response analysis showed evidence of a small and statistically non-significant link between a doubling of PM2.5 concentrations and dPFV worsening (0.9 percentage point increase, 95% CI: -0.1, 1.9, p = 0.079). Conclusions: In the first randomized, placebo-controlled trial designed to achieve improvements in asthma via reductions in wood stove-generated PM2.5, we found that air filters can significantly reduce PM2.5 and improve a marker of airway reactivity in children.

Silica Exposure and Effect on Peak Expiratory Flow: Slate Pencil Workers' Study.

Peak expiratory flow (PEF) is a spirometric test that detects obstructive changes in the respiratory tract; has good correlation with the FEV1; and is much less expensive, simpler, and easier to perform under field conditions than FEV1. Chronic silicosis is also known to have obstructive features in advanced stages. Thus, this study was performed to assess the effect of silica exposure on PEF and the factors related to it. The present study was carried out among 193 slate pencil cutting workers of Multanpura village of Madhya Pradesh, India. An interview technique was used to record demographic characteristics and occupational history on a predesigned form, which included a questionnaire regarding occupational history and silica-related respiratory morbidities. This was followed by a complete medical examination and measurement of PEF using a spirometer. The mean age was 43.35 ± 11.31 y, and the mean duration of exposure was 18.72 ± 9.33 y. In the present study, PEF was found to be significantly reduced in those age ≥40 y, those who were female, those having duration of exposure >10 y, and those having respiratory morbidity, whereas the reduction in PEF was statistically nonsignificant for smokers. Higher age, female sex, higher duration of exposure, and respiratory morbidity were found to be important correlates of PEF.

Diurnal Variation of Peak Expiratory Flow Rate in Healthy Young Adults of North East of India

PEF measurement is a simple and easy procedure to evaluate and assess the degree of 24hrs variation (circadian) in lung function. Thus this study was undertaken to study the diurnal variation in peak expiratory flow (PEF) in 60 healthy non-smoking adults of Northeast, in the age group between 18-24 years. The PEFR (L/min) was measured with mini Wright’s peak flow meter for three times a day, morning, afternoon and evening. The diurnal variation was observed with lowest values in the morning followed by progressive rise peaking in the evening. Diurnal variation for individual subject was calculated by using amplitude percent mean (A%M). We conclude that a definite pattern of diurnal variation in PEF is seen in healthy population and its knowledge is important for meaningful interpretation of PEF recordings in disease condition.

Preoperative maximal expiratory pressure is associated with duration of invasive mechanical ventilation after cardiac surgery: An observational study

ObjectiveTo evaluate the association of maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), and peak expiratory flow (PEF) with total duration of invasive mechanical ventilation (IMV) in subjects undergoing cardiac surgery. BackgroundProlonged IMV is associated with respiratory infections, prolonged hospitalization, and increased mortality. Pulmonary function tests can help predict postoperative outcomes after cardiac surgery. MethodsWe recruited subjects admitted for cardiac surgery. All MIP, MEP, and PEF measurements were performed before surgery. Multivariable analysis was performed using a multiple linear regression model to control for possible confounders and test for association of MIP, MEP, and PEF with IMV duration. ResultsOverall, 125 subjects were included in the study. Higher MEP was associated with reduced duration of IMV after adjustment for confounders (P = 0.015), but no such association was observed between MIP or PEF and IMV. ConclusionsIn subjects undergoing elective cardiac surgery, preoperative MEP is associated with IMV duration.

Epidemiology of bronchial asthma in school children (10-16 years) in Srinagar.

Objectives:To assess the epidemiological profile of asthma in school going children in Srinagar, Kashmir.Study design:Cross-sectional study.Setting:Thirty-one schools with proportionate representation from both government and private schools as well as from primary, middle, and high schools.Participants:School children aged 10–16 years with equal representation of sex and all ages.Main Outcome Measure:Prevalence of current and past asthma.Methods and Results:After administering a modified pretested questionnaire, peak expiratory flow measurement was carried. Children who had asthma-like symptoms or positive family history of asthma or physician-labeled asthma were subjected to spirometry and bronchodilator reversibility. Out of 806 children, bronchial asthma was seen in 60 (prevalence of 7.4%) which included 34 boys and 26 girls. Majority of asthmatic children (78.3% [n = 47]) had probable asthma; 6.7% (n = 4) had definite asthma; and 15% (n = 9) had physician-diagnosed asthma. Majority of children had intermittent asthma (78.3% [n = 47]). Mild persistent asthma was seen in 12.7% (n = 7) and 10% (n = 6) had moderate persistent asthma. None of the children had severe persistent asthma. The prevalence of current asthma was 3.2% (n = 26). On univariate analysis, the factors found to be statistically significant were family history of asthma (odds ratio [OR] =8.174; confidence interval [CI] =4.403–15.178), seasonal cough (OR = 4.266; CI = 2.336–7.791), allergic rhinitis (OR = 2.877; CI = 1.414–5.852), atopic dermatitis (OR = 6.597; CI = 2.72–16.004), and obesity (OR = 6.074; CI = 2.308–18.034). On multivariate analysis, family history, seasonal cough, allergic rhinitis, atopic dermatitis, and obesity were found to be significant independent risk factors.Conclusions:Srinagar qualifies as a low prevalence area for bronchial asthma in the age group of 10–16 years. Majority of children had mild intermittent asthma resulting in under diagnosis and wrong treatment.

Are serum eosinophilic cationic protein levels of toll collectors affected by diesel exhaust exposure?

Objective:There are few studies on the diesel exhaust particulates (DEP) / eosinophilic cationic protein (ECP) level relationship. This study aimed to detect ECP levels in a highly DE exposed group, named as toll collectors.Methods:In a cross-sectional study, levels of serum ECP, rates of respiratory symptoms, mean levels of respiratory functions, smoking status, and variations in peak expiratory flow (PEF) during weekends and working days were compared for 68 toll collectors (TC) (range of age, 24-48 years) and 28 controls (range of age, 25-61 years). All subjects in the study group were men.Results:No significant difference was observed in terms of symptoms and smoking rates between the toll collectors and control group. The number of toll collectors [12/68 (17.7%) vs 1/28 (3.5%)] with diurnal PEF variability in the working period was higher than that of controls (p=0.058). Mean ECP level of toll collectors was higher than that of controls (32.8 vs 21.4 ng/L), but the difference was not significant. Mean ECP levels were higher in subjects experiencing diurnal PEF variability during work and off-work periods (34.9 vs 28.3 ng/L, p=0.410).Conclusions:Serial PEF measurements combined with serum ECP measurements did not add a new tool to detect the sensitivity of workers dealing with DE. Much more diesel exhaust exposed workers should be included to search for cheap and available methods when evaluating airway.

Horse Allergy: Curly Horses Allow Horse Allergic Riders To Ride Again.

To test the hypothesis that so called hypoallergenic horses (Curly horses) allow horse allergic riders to ride again, we investigated 40 horse allergic riders in a period of 37 months. Methods: We tested these patients (pts.) by skin prick test (SPT) with different non-curly and Curly horses and studied the riding hours and horse brushing by measurements of peak expiratory flow (PEF) and Tiffeneau tests (FEV1) as well as peak nasal inspiratory flow (PNIF) over 12 months. The results in 37/40 pts. showed no relevant reactions of the lower airways or nasal flow. Only in 3/40 patients an initial significant fall of FEV1 was observed, reversed by a single inhalation of salbutamol and not repeated despite further riding contact. In contrast to other allergic events (e. g. baker's asthma) a further and regular contact with these horses abolished the mild allergic reactions of the start period of contact. This may be due to hypoallergenic properties of these horses, whose test material produces weaker reactions in the SPT than that of normal horses. After a period of three years, a loss of reactivity to normal horses could be confirmed in some of the riders. Conclusion: The tested purebreed Curly horses may be a suitable alternative for horse allergic riders if the methodological precautions of this study are followed.

AAIRS Score Overview: The Acute Asthma Intensity Research Score

Pediatric acute asthma exacerbations are responsible for 640,000 emergency department (ED) visits each year and are the most frequent reason for childhood hospitalization in the United States.1 Expert panel guidelines recommend that treatment and hospitalization decisions be made based on assessment of severity and response to treatment. However, these guidelines specify severity assessment that includes spirometry for peak expiratory flow measurement (FEV1), measures that are generally unavailable or difficult for pediatric patients to perform during exacerbations.2–4 The Acute Asthma Intensity Research Score (AAIRS) is a 17-point (0 to 16, with 16 most severe) bedside severity score that uses readily evaluated physical signs (Figure 1) and that has been validated against the criterion standard %-predicted FEV1.5, 6 We are not aware of training videos published in the peer-review literature for acute asthma severity scores. The accompanying video follows the course of a young child with a moderately severe asthma exacerbation over several hours of ED care to demonstrate the seven physical signs comprising the AAIRS and how they are to be evaluated for AAIRS scoring. The protocol under which the AAIRS was developed was approved by our institutional review board, and development of the training video was a quality improvement initiative requested by our clinical leadership.

Cleaning products and short-term respiratory effects among female cleaners with asthma

ObjectiveWe evaluated the short-term effects of exposure to cleaning products on lung function and respiratory symptoms among professional cleaning women.MethodsTwenty-one women with current asthma and employed as professional cleaners participated...

Air Pollution and Lung Function in Dutch Children: A Comparison of Exposure Estimates and Associations Based on Land Use Regression and Dispersion Exposure Modeling Approaches.

BackgroundThere is limited knowledge about the extent to which estimates of air pollution effects on health are affected by the choice for a specific exposure model.ObjectivesWe aimed to evaluate the correlation between long-term air pollution exposure estimates using two commonly used exposure modeling techniques [dispersion and land use regression (LUR) models] and, in addition, to compare the estimates of the association between long-term exposure to air pollution and lung function in children using these exposure modeling techniques.MethodsWe used data of 1,058 participants of a Dutch birth cohort study with measured forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) measurements at 8 years of age. For each child, annual average outdoor air pollution exposure [nitrogen dioxide (NO2), mass concentration of particulate matter with diameters ≤ 2.5 and ≤ 10 μm (PM2.5, PM10), and PM2.5 soot] was estimated for the current addresses of the participants by a dispersion and a LUR model. Associations between exposures to air pollution and lung function parameters were estimated using linear regression analysis with confounder adjustment.ResultsCorrelations between LUR- and dispersion-modeled pollution concentrations were high for NO2, PM2.5, and PM2.5 soot (R = 0.86–0.90) but low for PM10 (R = 0.57). Associations with lung function were similar for air pollutant exposures estimated using LUR and dispersion modeling, except for associations of PM2.5 with FEV1 and FVC, which were stronger but less precise for exposures based on LUR compared with dispersion model.ConclusionsPredictions from LUR and dispersion models correlated very well for PM2.5, NO2, and PM2.5 soot but not for PM10. Health effect estimates did not depend on the type of model used to estimate exposure in a population of Dutch children.CitationWang M, Gehring U, Hoek G, Keuken M, Jonkers S, Beelen R, Eeftens M, Postma DS, Brunekreef B. 2015. Air pollution and lung function in Dutch children: a comparison of exposure estimates and associations based on land use regression and dispersion exposure modeling approaches. Environ Health Perspect 123:847–851; http://dx.doi.org/10.1289/ehp.1408541

Can serial PEF measurements separate occupational asthma from allergic alveolitis?

Occupational asthma commonly results in work-related changes in serial peak expiratory flow (PEF) measurements. Whether alveolitis can result in similar changes is unknown. To identify differences and similarities of serial PEF between workers with occupational alveolitis and asthma seen during an outbreak investigation in a factory with metal-working fluid exposure. Workers with respiratory symptoms and rest-day improvement were identified by questionnaire. Each was asked to measure PEF 8 times daily for 4 weeks at home and work. Alveolitis was subsequently diagnosed from a validated scoring system including radiological changes, carbon monoxide diffusing capacity, bronchoalveolar lavage and biopsy results. Occupational asthma was confirmed with a positive Oasys score >2.5 and a mean rest-work PEF >16 l/min from serial 2-hourly PEF measurements. The Oasys PEF plotter calculated differences between rest and workdays for mean PEF, diurnal variation and the scores were used to confirm an occupational effect (Oasys, area between curve and time point). Records were compared between the alveolitis group and the group with occupational asthma without alveolitis. Forty workers with occupational asthma and 16 with alveolitis had indistinguishable PEF changes on workdays in terms of magnitude (median reduction 18.5 and 16.1 l/min, respectively) and diurnal variation. Immediate reactions were more common with occupational asthma and late reactions more common with alveolitis. PEF responses to metal-working fluid aerosols do not distinguish occupational asthma from alveolitis except in timing. They can be used to identify the workplace as the cause of asthma and also alveolitis.

Los Angeles phonospirometry technique: creating a normogram that correlates with peak expiratory flow measurements in children

Objective: Measurement of peak expiratory flow (PEF) is recommended in the assessment of patients with asthma. However, the use of PEF involves multiple barriers, which have limited its use. Phonospirometry, as assessed by a novel Los Angeles phonospirometry technique, has shown good correlation to standard PEF measurements in a pilot study on symptomatic patients with asthma. We sought to develop a normogram for phonospirometry, and to validate the PEF normogram. Methods: A convenience sample of asymptomatic children ages 3–17 years old was approached for participation in the Emergency Department. Sample size calculations determined that at least 30 children per age group (n = 450) were needed. Children were asked to perform PEF measurements and phonospirometry, measured as the length of time (in s) the child was able to chant “lalala” in a single breath. Results: 510 children were enrolled. Spearman's rho between PEF and phonospirometry was 0.722. Phonospirometry correlated with both age and height, with a spearman rho of 0.697 and 0.696, respectively. This was slightly lower than the correlation of PEF with age and height with spearman rhos of 0.877 and 0.902, respectively. A normogram was developed for phonospirometry based on age and height. Conclusions: This study determined normal value ranges for the Los Angeles phonospirometry technique for age and height, and also showed that the technique has good correlation with PEF. This technique may be used to assess a pediatric patient with an acute asthma exacerbation.

Asthma spreading and primary diagnostics problems in rural regions of Kazakhstan

Methods Screening study amongst the population of two villages of two different rural regions was conducted. 1204 patients became subjects. 681 women and 523 men, their age between 16 and 79 (average 41.3±4.17). During the first stage of the study, they underwent meticulous survey and peak expiratory flow measurement. In the second phase of the study, we examined patients of the study group with the use of an algorithm of asthma management developed by our team. It is a step-by-step strategy, created for general practitioners and medical assistants. This algorithm was designed to facilitate the early detection of asthma.

Questions and commentary on the article ‘Daily changes of peak expiratory flow and respiratory symptom occurrence around a soy processing factory’

Dear Editor, An interesting article by Heederik D et al. was published in a recent number of Ann Agric Environ Med. (2014, vol. 21, no 1, 5–10) concerning the relationship between, on the one hand, concentration of soy allergens in the proximity of a factory producing soy oil and intensity of respiratory symptoms, daily changes of peak expiratory flow (PEF) and bronchodilator utilization [1]. The authors tested daily changes of PEF, bronchodilator use and respiratory symptoms in two groups of people: those living in the vicinity of the soy oil factory and habitants living in the control area located about 5 km from the factory. They found positive skin prick tests (SPTs) to common allergens among 81% of participants and positive results of SPTs to soy in 11–12% examined people. The authors concluded that sensitization to soy allergen was not increased among the people living in the proximity of the factory; however, the soy-sensitized individuals living in the surroundings of the factory reported more respiratory symptoms, greater bronchodilator utilization, and lower PEF after having been downwind of the factory. Peak expiratory flow measurements, above all, are a useful method of evaluation of asthma control. Daily variability of PEF of more than 20% can be a symptom of pathological bronchial tree hyperresponsiveness (BHR) and bad asthma control [2]. BHR is an individual feature and is not directly correlated with the concentration of aeroallergens. Among people with allergic rhinoconjunctivitis and without bronchial asthma and/or BHR, the daily variability of PEF could be slight and may be comprised in the normal value for healthy people. The authors found positive results of allergic skin prick tests in the majority of participants from both groups (81%). Unfortunately, they did not report the percentage of people with asthma in both groups. This is important information, insofar as, for example, a higher incidence of bronchial asthma and BHR among participants from the study group may have influence on the greater variability of PEF, respiratory symptoms and bronchodilator consumption. Additionally, on the other hand, the lack of people with bronchial asthma in the control group could result in small daily PEF changes, scant other symptoms. It is also worth considering the smoking status of the participants in the statistical analysis. In the study group, the percentage of current smokers was higher than in the control; obviously, tobacco addiction has a significant influence on bronchial hyperresponsiveness and value of spirometric function tests [3].

Respiratory function of workers at a construction company in Bangalore Urban district

Introduction: Construction sector is one among the largest employers in India. Most of the construction workers are migrants susceptible to occupational health hazards. Construction workers are exposed to a variety of dust and chemicals that may pose a risk to the respiratory system. There is paucity of data on the respiratory function of construction workers in India. Objectives: The objectives were to assess the respiratory function of construction workers and to study possible factors associated with the respiratory function of these construction workers. Methodology: A cross sectional study was conducted among 197 workers in a construction company in Bangalore Urban district from November - December 2010. The study tools were an interview schedule to study the respiratory function and possible associated factors and clinical examination which included anthropometry (height, weight) and Wright’s mini peak flow meter to measure peak expiratory flow rate (PEFR). The data was analyzed using standard statistical software. Results: Among male workers, the mean PEFR was 457.43 l/min (SD 65.38 l/min) while among female workers, the mean PEFR was 326 l/min (SD 46.95 l/min). Respiratory function as measured by peak flow meter was decreased in 127 (64.5%) workers. The current reported tobacco smoking was 41.2% (77) among 187 males. Only 3 (1.5%) workers reported to use of face mask. There was no significant association (p>0.05) between respiratory function, and duration of work more than a year at construction company, use of face mask or smoking. Conclusion: This preliminary study revealed that the respiratory function among the workers was decreased. More precise studies with population control matched for age using pulmonary function tests are needed to assess the findings of the study.DOI: http://dx.doi.org/10.3126/ijosh.v4i1.10000

Asthma Diagnosis in Spain: Survey of Opinions, Attitudes and Knowledge among Primary Care Physicians

Background: Asthma is frequently misdiagnosed. Peak expiratory flow (PEF) measurement is easy and very useful for asthma diagnosis in primary care. Objectives: The DIANA project aimed to assess the impact of a course on PEF measurement among primary care physicians in Spain. Methods: A 7-item questionnaire was sent to selected primary care physicians (Phase A). Respondents were then invited to take a web-based course on PEF in asthma diagnosis. Finally, the questionnaire was again sent to all physicians (Phase B). Questionnaires also asked for demographical data such as age, sex, speciality, route of access to speciality, and geographical area. A comparative statistical analysis was performed on the results of both questionnaires. An extended analysis was performed later. Answers were analysed by percentages and using McNemar’s test. The planned duration of the project was one year. Results: No statistically significant differences in percentages between the two phases were found for Items 1 (related to asthma diagnosis) and 4 (related to availability and use of PEF meter). However, for Item 2 (related to diagnosis of occupational asthma) differences were significant (p<0.05), with an odds ratio (OR) of 1.50 for those participating in Phase B. Differences were also significant (p<0.05) for those who took the course, with an OR of 1.37. For Item 3 (related to the usefulness of measuring daily variability of PEF), there were also significant differences (p<0.05) between the two phases, with an OR of 1.39. There were also significant differences (p<0.05) for those who took the course, with an OR of 1.53. Conclusions: The first four results of the survey showed that educational intervention may improve knowledge of the usefulness of PEF in asthma diagnosis among primary care physicians. However, the high percentages of correct answers among those who did not take the course merit further investigation.

Extrabronchial symptoms and late phase reaction enhance the diagnostic value of aspirin bronchial challenge.

IntroductionLysine aspirin (l-ASA) bronchial challenge can be used in the diagnostics of aspirin exacerbated respiratory disease. It is safer than oral challenge, however it is characterized by a lower sensitivity.AimWe sought to investigate whether additional indicators of the positive result of l-ASA bronchial challenge, i.e. late phase reaction (LPR) and extrabronchial symptoms (EBS), may enhance its diagnostic value.Material and methodsSixty-seven patients with a positive history of asthma exacerbated by aspirin and/or other non-steroidal inflammatory drugs underwent l-ASA bronchial challenge. The control groups comprised 15 aspirin tolerant asthmatics and 15 healthy subjects. Forced expiratory volume in 1 s (FEV1) and 24-hour peak expiratory flow (PEF) measurements were performed in all subjects in order to recognize early and late response to l-ASA. All subjects underwent oral ASA challenge 2 weeks after l-ASA bronchial challenge.ResultsBasing on FEV1 and PEF results, early reaction was present in 50.7% of patients, early and LPR in 29.9% and LPR in only 10.4% of aspirin exacerbated respiratory disease patients. The EBS were noted in 31.3% of subjects. Inclusion of LPR and EBS as positive criteria of the challenge increased sensitivity to 94.0%.ConclusionsThese results indicate that both LPR and EBS should be considered as positive criteria of aspirin bronchial challenge as they enhance its diagnostic value.

Critical pathway of acute asthma attack for the Emergency Center: patients' outcomes and effectiveness

Purpose: Early recognition and management of asthma attack is critical before it becomes worse. We developed critical pathway (CP) of asthma attack at Emergency Center (EC) for making undelayed decision and management of asthma attack. Methods: Acute asthma attack assessment and treatment (4AT) CP began on April 1st 2012 and recruited the patients for 18 months. This study enrolled the patients who were older than 15 years and visited EC for dyspnea and wheezing. Initial assessment was done measuring peak expiratory flow rate (PEFR), oxygen saturation (SaO2). Once CP is activated, oxygen, inhalation of short acting β2 agonist, and injection of corticosteroid were administered to the patients. Every hour after CP activated, we reassess the patients’ response and make decisions whether to admit or discharge. Results: Until January 10th 2014, 62 patients enrolled in this study. Seven patients hospitalized for asthma and 40 patients discharged. The other 15 patients were deactivated as they were diagnosed of heart failure, myocardial infarction, aortic dissection, anaphylaxis, chronic obstructive pulmonary disease and pneumonia for the causes of dyspnea. Mean Interval from EC arrival to 4AT activation was 32.6±29.1 minutes and the mean interval from 4AT activation to position decision was 254.5±302.0 minutes. Among 47 patients who were diagnosed with asthma attack, 13 patients were not aware of asthma before this attack. Forty patients were discharged at EC after management of CP. Among them, 34 patients revisited clinic, but 6 patients did not. We called back to the lost 6 patients but only 3 patients were connected. Even they visited EC due to asthma attack, 2 patients had no insight of importance of regular management and the other one promised to revisit. Conclusion: CP was successful for early management of asthma attack. However, 15% of discharged patients never show up again. So, education program about the importance of ongoing management of asthma for prevention of asthma attack is needed. (Allergy Asthma Respir

Explorations cliniques et fonctionnelles dans la BPCO : de la détection au suivi

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.

Comparison of US emergency department acute asthma care quality: 1997-2001 and 2011-2012

It remains unclear whether the quality of acute asthma care in US emergency departments (EDs) has improved over time. We investigated changes in concordance of ED asthma care with 2007 National Institutes of Health guidelines, identified ED characteristics predictive of concordance, and tested whether higher concordance was associated with lower risk of hospitalization. We performed chart reviews in ED patients aged 18 to 54 years with asthma exacerbations in 48 EDs during 2 time periods: 1997-2001 (2 prior studies) and 2011-2012 (new study). Concordance with guideline recommendations was evaluated by using item-by-item quality measures and composite concordance scores at the patient and ED levels; these scores ranged from 0 to 100. The analytic cohort comprised 4039 patients (2119 from 1997-2001 vs 1920 from 2011-2012). Over these 16 years, emergency asthma care became more concordant with level A recommendations at both the patient and ED levels (both P < .001). By contrast, concordance with non-level A recommendations (peak expiratory flow measurement and timeliness) decreased at both the patient (median score, 75 [interquartile range, 50-100] to 50 [interquartile range, 33-75], P < .001) and ED (mean score, 67 [SD, 7] to 50 [SD, 16], P < .001) levels. Multivariable analysis demonstrated ED concordance was lower in Southern and Western EDs compared with Midwestern EDs. After adjusting for severity, guideline-concordant care was associated with lower risk of hospitalization (odds ratio, 0.37; 95% CI, 0.26-0.53). Between 1997 and 2012, we observed changes in the quality of emergency asthma care that differed by level of guideline recommendation and substantial interhospital and geographic variations. Greater concordance with guideline-recommended management might reduce unnecessary hospitalizations.