A literature review of the evidence that a 12% improvement in FEV1 is an appropriate cut-off for children

Introduction: A well-performed spirometry, using a change in forced expiratory volume in one second (FEV₁) after albuterol, is commonly used to support the likelihood of an asthma diagnosis. The current standard, accepted by the 2007 National Heart Lung and Blood Institute Asthma Expert Panel Report-3 (EPR-3) guidelines, is a 12% improvement in the FEV₁ after a bronchodilator. Objective: We sought to determine whether existing studies support or refute using a 12% improvement as a significant change in FEV₁ in children and adolescents. Data sources: We reviewed the literature of children and adolescents using Medline searches to discover pertinent population studies and comparative studies that included FEV₁ measurements. Result: The majority of the discovered studies suggest a less stringent improvement in FEV₁ in children might be applicable. Conclusion: Supported by the published literature, we suggest an alternative interpretive strategy of expressing the results of a spirometry measurement when a diagnosis of asthma in a child is being considered using a bronchodilator response.     

Effect of Bilateral Lung Volume Reduction Surgery on FEV1 Decline in Severe Emphysema

Study Objective. To examine whether lung volume reduction surgery (LVRS) alters the anticipated natural rates of decline in FEV₁. Design. Retrospective analysis of spirometry results (188 studies) in patients before and after bilateral LVRS. Setting. Large, urban, academic medical center. Patients. 25 patients with severe emphysema (mean (SD) age 60 ± 8 yrs; FEV₁ 0.74 ± 0.29 L, 29% predicted). Interventions. Bilateral LVRS performed via median sternotomy, with areas targeted for resection based on preoperative evaluation using high-resolution computed tomography, quantitative perfusion scans, and intraoperative inspection of the lungs. Linear regression analysis was performed on each patient using all serial postbronchodilator FEV₁ values from before and after LVRS. Results. Lung function data were available between 2–1001 days prior to LVRS and 71–1169 days after LVRS. Comparison of single pre- and post-LVRS FEV₁ results confirmed a significant post-operative (3 month) improvement in lung function. The calculated rate of decline in FEV₁ prior to LVRS was 202 ± 205 mL/yr. Following LVRS, the rate of decline in FEV₁ was unchanged at 178 ± 150 mL/yr (p = 0.64). Conclusions. In patients with severe emphysema, bilateral LVRS does not appear to significantly alter the rate of FEV₁ decline.     

Utility of Portable Spirometry in a Pediatric Emergency Department in Children with Acute Exacerbation of Asthma

Objectives. The primary purpose of this study was to determine if portable spirometers can be successfully used in an emergency department (ED) in children with an acute exacerbation of asthma. The secondary purpose of this study was to determine if a validated clinical asthma score (CAS) correlates with the spirometry results in children with an acute exacerbation of asthma. Methods. Children between the ages of 6 and 17 years who presented to an urban free-standing children's hospital ED with an acute exacerbation of asthma were enrolled in our study. On arrival, the CAS was recorded and then portable spirometry was performed. Attempts were continued until acceptable and reproducible flow loop measurements were obtained or until the patient was unable to perform further attempts. Outcomes included success at spirometry and correlation of spirometry with the CAS. Results. A total of 101 patients were enrolled in this study. Of those patients, only 35 (35%) were able to successfully perform portable spirometry. Successful spirometry attempts were associated with older age (10.4 vs. 8.9, p = .01), lower respiratory rates (24.8 vs. 30.2, p = .001), lower heart rates (110 vs. 124, p = .004), and lower CASs (8.4 vs. 9.7, p = .001). Increasing asthma severity correlated with a decreased likelihood of successfully obtaining a useful forced expiratory volume in 1 second (FEV₁) measurement (p = .013). Compared with cases of mild asthma, a patient with moderate asthma is 33% less likely to be able to perform spirometry, and a patient with severe asthma 93% less likely to perform spirometry. The CAS correlated poorly with the more objective measure of FEV₁% predicted in those with mild asthma. Conclusion. Many children are incapable of using portable spirometry for the evaluation of acute exacerbations of asthma in the ED. The clinical asthma scoring system demonstrated poor correlation with portable spirometry measurements in terms of severity classification.     

The FEV1/FEV6 ratio is a good substitute for the FEV1/FVC ratio in the elderly.

AIMS: To determine the agreement between the FEV1/FEV6 ratio and the FEV1/FVC ratio in an elderly population. METHOD: The study sample consisted of 3874 participants in a cross-sectional population survey in Troms?, Norway, aged 60 years or more, in whom acceptable spirometry had been obtained. Mean differences between the FEV1/FEV6 ratio (%) and the FEV1/FVC ratio (%) were calculated according to age, sex, smoking habit, and the degree of airflow limitation. ROC-curve analysis and Kappa-statistics were used to estimate the utility of the FEV1/FEV6 ratio in predicting an FEV1/FVC ratio < 70%. RESULTS: The mean difference between FEV1/FEV6% and FEV1/FVC% was 2.7% in both men and women. The difference between the two measures increased somewhat with increasing age, and was more pronounced with smoking and decreasing FEV1/FVC ratio. The value for the FEV1/FEV6 ratio which best predicted an FEV1/FVC ratio of 70%, was 73%, and a very good agreement was found between these two cut-off values (kappa = 0.86). CONCLUSION: The FEV1/FEV6 ratio appears to be a good substitute for the FEV1/FVC ratio in an elderly population.     

The Efficacy and Tolerability of Inhaled Montelukast Plus Inhaled Mometasone Compared with Mometasone Alone in Patients with Chronic Asthma

Background. The efficacy of oral montelukast in chronic asthma is well established. Montelukast is also an effective adjunctive therapy to inhaled corticosteroids (ICS) in asthma uncontrolled on ICS alone. Inhaled montelukast was recently shown to provide significant bronchodilation compared with placebo in patients with chronic asthma. The purpose of this study was to evaluate the efficacy of inhaled montelukast added to inhaled mometasone. Methods. This was an 8-week, multicenter, randomized, double-blind, placebo-controlled study comparing once-daily inhaled montelukast 1 mg plus inhaled mometasone 220 μg (delivered by separate dry powder inhalers) with placebo plus inhaled mometasone 220 μg. Men and women aged 15–85 years with chronic asthma, forced expiratory volume in 1 second (FEV₁) 50–80% of the predicted value, and β-agonist reversibility ≥12% were eligible. Patients were required to meet a minimum symptom threshold while receiving open-label inhaled mometasone during a 3-week prestudy/run-in period. Patients received blinded (montelukast vs. placebo) treatment for 2 weeks, entered a 1-week washout period, then crossed over to the other treatment for 2 weeks. The primary endpoint was the average change from baseline in FEV₁ over the 2-week treatment period. Secondary endpoints included daytime and nighttime symptom scores. Other endpoints included short-acting β-agonist (SABA) use, asthma exacerbations, asthma control, peak expiratory flow (PEF), and blood eosinophil count. Results. A total of 134 patients were randomized. For the primary endpoint, change from baseline in FEV₁, inhaled montelukast plus inhaled mometasone was significantly more effective than placebo plus inhaled mometasone (least squares mean 0.22 L vs. 0.17 L; p = .033 [two-sided at α = 0.05]). Inhaled montelukast plus inhaled mometasone was also significantly more effective than placebo plus inhaled mometasone in improving daytime asthma symptom scores (p = .005) and nighttime asthma symptom scores (p = .015), increasing the percentage of days with asthma control (p = .004), decreasing the percentage of days with asthma exacerbations (p ≤ .001), and decreasing the blood eosinophil count (p = .013). Differences were not significant on AM or PM PEF or SABA use, although the latter approached significance (p = .073). Both treatments were well tolerated. Conclusion. Inhaled montelukast plus inhaled mometasone was significantly more effective than placebo plus inhaled mometasone in improving FEV₁, symptoms, asthma control, and blood eosinophil count.     

A Randomized Study Comparing the Effect of Loratadine Added to Montelukast with Montelukast,Loratadine, and Beclomethasone Monotherapies in Patients with Chronic Asthma

Background. Loratadine added to montelukast has been suggested to improve endpoints of asthma. Objective. This study investigated the additive effects of concomitant montelukast and loratadine when compared with montelukast, loratadine, and inhaled beclomethasone monotherapies in asthma. Methods. Patients (N = 406) were 15 to 65 years of age with a forced expiratory volume in 1 second (FEV₁)-predicted of 50% to 85%, FEV₁ reversibility ≥ 15%, and a minimal level of daytime symptoms and β -agonist use. This three-part 2X2 crossover-study consisted of two double-blind 6-week treatment periods where patients were administered once daily oral montelukast 10 mg, loratadine 10 mg, montelukast 10 mg + loratadine 10 mg, or twice daily inhaled beclomethasone 200 μ g. A subsequent 48-week extension study compared montelukast+loratadine with beclomethasone. The primary endpoint was the percentage change from baseline in FEV₁. Results. Over 6 weeks of double-blind treatment, significant improvements (p < 0.05) in the primary endpoint of FEV₁ were seen for montelukast+loratadine versus loratadine (least-square mean percentage-point difference of 5.8%), beclomethasone versus montelukast+loratadine (2.35%), montelukast versus loratadine (5.94%), and beclomethasone versus montelukast (4.65%); a numerical improvement (p = 0.054) was seen for montelukast+loratadine versus montelukast (1.60%). Significant improvements for montelukast+loratadine versus montelukast were seen in some secondary endpoints (evening peak expiratory flow, nocturnal asthma symptom score, nocturnal awakenings, and asthma-specific quality of life) but not others. Significant improvements in most endpoints except daytime asthma symptoms score were seen for montelukast+loratadine versus loratadine. In the extension study, both montelukast+loratadine and beclomethasone improved several endpoints. All treatments were generally comparable in the percentage of patients with clinical and laboratory adverse experiences. Conclusion. In this study, the addition of loratadine to montelukast produced a small numerical, but not statistically significant, improvement in FEV₁ and, in general, no consistent improvement in other asthma endpoints. No improvement of montelukast+loratadine versus beclomethasone was seen in any endpoint.     

Bronchial Asthma Showing Reduction in FEV1 after Inhalation of Qvar™

The administration of Qvar (a hydrofluoroalkane-134a beclomethasone dipropionate; HFA-BDP) is highly useful for the treatment of patients with asthma. However, we found in a case of bronchial asthma that replacing the prior inhaled corticosteroids with Qvar resulted in temporary dyspnea and reduction in forced expiratory volume in 1 second (FEV₁). Qvar contains beclomethasone dipropionate combined with absolute ethanol and an alternative to fluorocarbon. The patient had complicated alcohol-induced asthma. FEV₁ decreased markedly and immediately after Qvar inhalation. The Qvar placebo is free of beclomethasone but contains other ingredients (ethanol and fluorocarbon). FEV₁ did not decrease after the Qvar placebo, Aldecin inhalation, and Qvar inhalation orally treated with atropine before inhalation of Qvar?. It seems unlikely that the components of Qvar (except beclomethasone) are responsible for the reduction in FEV₁ observed immediately after inhalation of Qvar. These findings would be noteworthy when using Qvar for Japanese patients with asthma known to have a relatively high frequency of the complication of alcohol-induced asthma.     

Portable Spirometry During Acute Exacerbations of Asthma in Children

Background. Spirometry is the gold standard for assessment of asthma and is objective and non-invasive. This is a pilot study to evaluate whether portable spirometry can be successfully performed by children in the pediatric emergency department for acute exacerbations of asthma. Methods. We enrolled children more than 6 years of age presenting to an urban pediatric emergency department with a history of asthma during an acute exacerbation. On arrival and after each bronchodilator treatment, vital signs and a clinical score were recorded. Portable spirometry was then performed. Attempts were continued until acceptable and reproducible measurements were obtained or until the patient was unable to perform further attempts. Outcomes included success at spirometry and correlation of spirometry with clinical signs. Results. Thirty-four subjects were enrolled with a median age of 12 years. Ninety-one percent of subjects completed at least one attempt at spirometry. Seventy-three percent of all spirometry attempts were reproducible. Portable spirometry demonstrated increased severity of the exacerbation in comparison to clinical signs and peak expiratory flow. Percent of predicted forced expiratory volume in 1 second, ratio of forced expiratory volume in 1 second to forced vital capacity, and peak expiratory flow are all poorly correlated with degree of wheezing, clinical score, respiratory rate, and oxygen saturation (r < 0.5). Conclusion. Portable spirometry can be successfully performed by children with acute exacerbations of asthma in the emergency department and demonstrated greater degrees of airway obstruction than did clinical signs. Spirometry provides objective, non-invasive measurements of the severity of airway obstruction in the emergency department for children with acute exacerbations of asthma.     

A Phase I Randomized,Placebo-Controlled,Dose-Exploration Study of Single-Dose Inhaled Montelukast in Patients with Chronic Asthma

Background. The efficacy of oral montelukast has been well established in asthma and allergic rhinitis in adults and children. The purpose of this study was to evaluate dose-related bronchodilation and tolerability of inhaled montelukast. Methods. Randomized, double-blind, crossover, adaptive-design study comparing single-dose administration of inhaled montelukast versus placebo in patients age 15–65 years with chronic asthma (n = 68). Montelukast was delivered as a witnessed dose through dry powder inhaler at doses of 25, 250, or 1000 μg, and doses of 50, 100, and 500 μg could be used if needed based on a prespecified dose–response algorithm. Each administration was followed by a 4- to 7-day washout period before crossing over to the next treatment. The primary endpoint was the change from baseline in a forced expiratory volume in 1 second (FEV₁) over the first 4 hours after administration, calculated as a time-weighted average (ΔFEV₁ [0–4 hours]). Other endpoints included the onset and duration of bronchodilation and the effect of albuterol when added to inhaled montelukast. Results. Over 4 hours postdose, and compared with placebo (least-squares [LS] mean 0.03 L), inhaled montelukast 100 μg (0.13 L; p ≤ .001), 250 μg (0.10 L; p < .01), and 1000 μg (0.12 L; p ≤ .001) had significantly greater ΔFEV₁ (0–4 hours). At 24 hours postdose, inhaled montelukast 100 μg (0.10 L) and 1000 μg (0.09 L) had significantly greater bronchodilation compared with placebo (0.02 L; p < .05 vs. montelukast). Montelukast 1000 μg provided significant bronchodilation versus placebo within 20 minutes of administration (0.03 L vs. –0.05 L), whereas montelukast 100 μg provided significant bronchodilation relative to placebo within 2 hours of dosing (0.09 L vs. 0.01 L). Montelukast (pooled doses) plus albuterol was significantly more effective than montelukast plus placebo for ΔFEV₁ (0–90 minutes) (0.34 L vs. 0.15 L; p = .015). The tolerability of inhaled montelukast was similar to that of placebo. No serious adverse experiences were reported. Conclusions. Inhaled montelukast provided significant bronchodilation compared with placebo as early as 20 minutes after the administration that persisted for 24 hours and provided additive bronchodilation to albuterol.     

Bacterial Contamination of Spacer Devices Used by Asthmatic Children

Objectives. To investigate bacterial contamination in spacer devices used by asthmatic children and the device maintenance procedures practiced by parents. Methods. Spacer devices used by 62 asthmatic children were examined. Swabs taken from the inner surface of the reservoirs and face masks were cultured. Parents were interviewed regarding their spacer cleaning and disinfection routines. Results. Bacterial contamination was noted in 22 reservoirs (35.5%) and 16 masks (25.8%). Pseudomonas aeruginosa was isolated from 21.0% of the reservoirs and 14.5% of the face masks, Klebsiella pneumoniae from 6.5% and 4.8%, and Staphylococcus aureus from 9.7% and 8.1%, respectively. Only 34 parents (54.8%) reported that they received cleaning and maintenance instructions from the medical staff at initiation of spacer use by their child, and only 38 (61.8%) cleaned the device after each use. Conclusion. Bacterial contamination is common in spacer devices. This study demonstrates that contamination rates are significantly lower when parents clean and actually dry (preferably with an air blower) spacer devices after each use. Spacer device maintenance should be emphasized in education programs for managing asthma.     

The Diagnostic Importance of a Reduced FEV1/FEV6

Abstract

Background: On spirometry the FEV₁/FEV₆ ratio has been advocated as a surrogate for the FEV₁/FVC. The significance of isolated reductions in either the FEV₁/FEV₆ or FEV₁/FVC is not known. Methods: First-time adult spirograms (n = 22,837), with concomitant lung volumes (n = 12,040), diffusion (n = 14,154), and inspiratory capacity (n = 12,480) were studied. Four groups were compared. 1) Only FEV₁/FEV₆ reduced (n = 302). 2) Only FEV₁/FVC reduced (n = 1158). 3) Both ratios reduced (n = 6593). 4) Both ratios normal (n = 14,784). Results: In patients with obstructed spirometry (either a reduced FEV₁/FVC and/or FEV₁/FEV₆), 3.8% only had a reduced FEV₁/FEV₆, while 14.4% only had a reduced FEV₁/FVC. The mean FEV₁ was lower when both ratios were reduced. The group with only a reduced FEV₁/FEV₆, compared to only the FEV₁/FVC reduced, had a lower FEV₁, FVC, BMI, Expiratory Time, and IC (p values < 0.0001). DLCO was also lower (p = 0.005), and the FEV₁/FVC and RV/TLC were higher (p values < 0.0001). When the patients with only a reduced FEV₁/FEV₆ had a subsequent spirogram, 60% had a reduced FEV₁/FVC when their mean expiratory times were 3.5 seconds longer. Ninety percent of this group had strong clinical evidence of airways obstruction. Conclusions: The FEV₁/FEV₆ is not as sensitive as the FEV₁/FVC for diagnosing airways obstruction, but in the presence of a normal FEV₁/FVC, subjects have greater physiologic abnormalities than when only the FEV₁/FVC is reduced. The FEV₁/FEV₆ ratio should not replace the FEV₁/FVC as the standard for airways obstruction, but there is benefit including this measurement to identify individuals with greater air trapping and diffusion abnormalities.     

Effect of Dust Aerosol in Patients with Asthma

Objective. Sandstorms frequently cause adverse health effects especially in patients with asthma. The aim of our research was to explore the mechanism of sandstorm-induced asthmatic exacerbation by administering dust aerosol through an environmentally controlled exposure chamber. Methods. Four samples of soil (Ganganagar clay, Bikaner sand, Jaipur sand, and Ganganagar sand) were collected from three sandstorm-prone areas of Rajasthan, the desert state of India. Twenty patients with asthma, who had stable disease with a forced expiratory volume in first second (FEV₁) more than 70% of predicted, volunteered to participate in this randomized single-blind placebo-controlled crossover study. The four samples of dust and placebo were administered randomly on 5 study days. FEV₁ was measured for the next 60 minutes and the maximal decline in FEV₁ (ΔFEV₁) from baseline was measured. The samples of dust were also analyzed for particle size and adhesiveness. Results. The maximal decline in FEV₁ was observed 15 minutes post-exposure with all dust samples. Mean ΔFEV₁ was 0.69 ± 0.08 liters for Ganganagar clay, 0.52 ± 0.06 liters for Bikaner sand, 0.39 ± 0.07 liters for Jaipur sand, and 0.32 ± 0.04 liters for Ganganagar sand dust aerosol samples. Decline in FEV₁ correlated with volume of dust particles with size <10 μm (PM₁₀) and adhesiveness of the dust particles. Conclusion. Smaller-size sandstorm dust particles with higher adhesive properties have a greater potential of aggravating asthma.     

Fluticasone Propionate HFA-134a Pressurized Metered-Dose Inhaler in Adolescents and Adults with Moderate to Severe Asthma

In this randomized, double-blind, placebo-controlled trial, 397 patients with moderate to severe asthma, previously treated with bronchodilators alone, received fluticasone propionate 88, 220, or 440 μg twice daily, or placebo via metered dose inhaler (MDI) for 12 weeks. Mean change from baseline to endpoint in pre-dose percent predicted forced expiratory volume in one second (FEV₁) was greater (p < 0.001) in each fluticasone propionate group (9.0%, 88 μg bid; 9.8%, 220 μg bid; 11.2%, 440 μg bid) versus placebo (3.4%). Morning and evening peak expiratory flow (PEF), asthma symptoms, and supplemental albuterol use also improved in all fluticasone propionate groups versus placebo. The incidence of adverse events and 24-hour urine cortisol excretion rates were similar between active treatments and placebo.     

Evaluation of Bedoradrine Sulfate (MN-221), a Novel,Highly Selective Beta2-Adrenergic Receptor Agonist for the Treatment of Asthma via Intravenous Infusion

Background. The number of hospitalizations or deaths due to asthma, most of which result from acute exacerbations of asthma, has remained the same for the past 20 years. MN-221 (bedoradrine sulfate) is a novel, highly selective beta₂- (β₂-) adrenergic agonist administered via intravenous (IV) infusion in development for the treatment for acute exacerbation of asthma. Objectives. Trial MN-221-CL-004 assessed the safety profile and preliminary efficacy of MN-221 in escalating doses in patients with stable mild-to-moderate asthma. Study MN-221-CL-005 assessed the safety profile and preliminary efficacy of MN-221 in patients with stable moderate-to-severe asthma when given as a fixed dose over 1- or 2- hr infusion. Methods. Two randomized, placebo-controlled clinical trials (n = 40) were performed to evaluate the pharmacokinetic (PK) and clinical effects of a novel, highly selective β₂-agonist, MN-221, via IV infusion. Safety evaluations included vital signs, adverse events (AEs), clinical laboratory parameters, and electrocardiogram results. Efficacy evaluation included measurement of forced expiratory volume in 1 second (FEV₁) and PK parameters were additionally monitored. The study was reviewed and approved by the Institutional Review Board at each site. Results. Adverse effects were mild or moderate and there were no serious AEs or deaths during the studies. The most frequently reported AEs were tremor, hypokalemia, and headache. There were no consistent dose-dependent effects of MN-221 on any safety parameters, with the exception of heart rate, which was not considered to be clinically significant and did not require any treatment. Moderate hypokalemia occurred once in one subject in the MN-221-CL-004 study and twice in one subject in the MN-221-CL-005 study and were transient and returned to normal range following single oral potassium chloride treatments. PK assessments indicated a linear response in MN-221 plasma concentrations for the doses evaluated. Dose escalation results showed that mean changes in FEV₁ from pre-infusion were significantly greater than placebo and an overall dose response was statistically significant (p < .0001). Post-infusion FEV₁ improvements appeared to plateau at the 30 μg/min dose level despite a higher peak plasma concentration at 60 μg/min. Dose-rate escalation results demonstrated greater mean increases in change in FEV₁ compared to the placebo group with the largest increase associated with the higher MN-221 dose rate and peak plasma concentration. Conclusions. The safety profile of MN-221 and evidence of dose- and plasma-concentration-related bronchodilation supports further clinical development and suggests the potential for clinical benefit without increased clinical risk, particularly for patients where inhaled or nebulized therapy is not adequate or possible. Trial registry name and registration number:Name: MN-221-CL-005Number: NCT00679263     

Comparison of Mometasone Furoate Dry Powder Inhaler and Fluticasone Propionate Dry Powder Inhaler in Patients with Moderate to Severe Persistent Asthma Requiring High-Dose Inhaled Corticosteroid Therapy: Findings from a Noninferiority Trial

Background. Inhaled corticosteroids (ICSs) are one of the suggested first-line therapies for patients with persistent asthma of moderate severity. Methods: The efficacy and safety of mometasone furoate (MF) 400 μg twice daily (BID) and fluticasone propionate (FP) 500 μ g BID administered for 12 weeks via dry powder inhaler (DPI) were compared in a noninferiority trial, in adults with moderate-to-severe persistent asthma. The primary variable was the change from baseline in am peak expiratory flow rate (PEFR). pm PEFR, forced expiratory volume in 1 second (FEV₁), asthma symptoms, rescue medication use, response to therapy, exacerbation rates, and adverse events were also assessed. Results. The lower bound of 95% CIs for treatment differences in the primary variable ranged from 2.6% to 5.6% throughout the 12-week study and were within the prespecified noninferiority range. No significant between-group differences were observed in lung function, rescue medication use, response to therapy, exacerbation rates, or adverse events. At most of the weeks assessed, there were no between-group differences in asthma symptoms. Most adverse events were mild-to-moderate. Conclusion. MF-DPI 400 μ g BID was therapeutically equivalent to FP-DPI 500 μ g BID in patients with moderate-to-severe persistent asthma.     

Minimal Clinically Important Differences in COPD Lung Function

The FEV₁ is widely used by physicians in the diagnosis, staging, treatment, monitoring and establishing prognosis for patients with COPD. The MCID is the smallest difference which patients perceive as beneficial and which would mandate a change in patient management. A precise MCID for FEV₁ has not been established.

In attempt to establish a MCID for predose or trough FEV₁, several limitations need to be addressed. There are issues such as reproducibility, repeatability, acceptability, variability, placebo effect, and equipment effects. Patient factors, such as baseline level of FEV₁, albuterol reversibility, diurnal variation, influence the results.

Nonetheless, using anchoring techniques, a change in pre dose FEV₁ of about 100 mL can be perceived by patients, correlates with fewer relapses following exacerbations and is in the range usually achieved with bronchodilators approved for COPD.

In the future, consistent reporting of spirometric variables, such as a predose FEV₁ and other outcomes, can be incorporated into a more quantitative effort to establish the MCID. Also distributional/statistical methods may be useful in determining the MCID FEV₁.     

The Impact of Spirometry on Pediatric Asthma Diagnosis and Treatment

Research has shown that spirometry is underutilized in the clinical setting. This study profiles the use of spirometry in an asthma management program at an inner-city community health clinic. Eligible subjects included 56 children who presented with an acute asthma exacerbation. Physicians recorded patient diagnosis before and after viewing spirometry. Bivariate and multivariate analysis was used to determine associations between symptoms and forced expiratory volume in 1 second (FEV₁). Physicians changed 30.4% of patients' treatment plans after viewing spirometry results. Wheezing was significantly associated with FEV₁ in bivariate analysis; however, multivariate modeling failed to identify significant relationships. The use of spirometry influenced patient diagnosis and treatment.     

Individual FEV1 Trajectories Can Be Identified from a COPD Cohort

Objective: We aim to make use of clinical spirometry data in order to identify individual COPD-patients with divergent trajectories of lung function over time. Study Design and Setting: Hospital-based COPD cohort (N = 607) was followed on average 4.6 years. Each patient had a mean of 8.4 spirometries available. We used a Hierarchical Bayesian Model (HBM) to identify the individuals presenting constant trends in lung function. Results: At a probability level of 95%, one third of the patients (180/607) presented rapidly declining FEV₁ (mean -78 ml/year, 95% CI -73 to -83 ml) compared to that in the rest of the patients (mean -26 ml/year, 95% CI -23 to -29 ml, p ≤ 2.2 × 10^-16). Constant improvement of FEV₁ was very rare. The rapid decliners more frequently suffered from exacerbations measured by various outcome markers. Conclusion: Clinical data of unique patients can be utilized to identify diverging trajectories of FEV₁ with a high probability. Frequent exacerbations were more prevalent in FEV₁-decliners than in the rest of the patients. The result confirmed previously reported association between FEV₁ decline and exacerbation rate and further suggested that in clinical practice HBM could improve the identification of high-risk individuals at early stages of the disease.     

A multifaceted community-based asthma intervention in Chicago: effects of trigger reduction and self-management education on asthma morbidity

Introduction. In the exercise challenge test (ECT), a drop in forced expiratory volume in the first second (FEV₁) of between 10 and 15% is the determinant variable for a diagnosis of exercise-induced bronchospasm. Hypothesis. The use of FEV₁ plus mean forced expiratory flow between 25% and 75% of the forced vital capacity (FEF_25–75%) may increase the sensitivity of the ECT in asthmatic children. Specific objective. To compare FEV₁ and FEF_25–75% changes in a group of asthmatic and healthy children. Methodology. This was a cross-sectional study. Asthmatics were categorized by their severity (GINA) and after 1 month without controller therapy, an ECT was done under standard protocol. As well, a questionnaire about rhinitis and asthma was conducted with the entire population. ROC curves were used for analysis. Results. A total of 147 children (34 healthy and 113 asthmatics, 18 and 58 males, respectively) were evaluated. Divided into healthy children and intermittent, mild and moderate persistent asthmatics, they had similar average ages (9.4, 9.48, 8.97, and 11.2 years, respectively). Using a 15% fall in FEV₁, we obtained 29% sensitivity and 100% specificity. However, when we used a 10% fall in FEV₁, sensitivity was 47% and specificity was 97%. Adding a 28% fall in FEF_25–75%, sensitivity was 52% and specificity was 94%. Conclusion. This study suggests that test sensitivity can increase by using a lower FEV₁ cut-off (10%) and adding a 28% fall in FEF_25–75%.