The impact of spirometry on pediatric asthma diagnosis and treatment

Global, Race-Neutral Reference Equations and Pulmonary Function Test Interpretation

Importance

Race and ethnicity are routinely used to inform pulmonary function test (PFT) interpretation. However, there is no biological justification for such use, and it may reinforce health disparities.

Objective

To compare the PFT interpretations produced with race-neutral and race-specific equations.

Design, Setting, and Participants

In this cross-sectional study, race-neutral reference equations recently developed by the Global Lung Function Initiative (GLI) were used to interpret PFTs performed at an academic medical center between January 2010 and December 2020. The interpretations produced with these race-neutral reference equations were compared with those produced using the race and ethnicity-specific reference equations produced by GLI in 2012. The analysis was conducted from April to October 2022.

Main Outcomes and Measures

The primary outcomes were differences in the percentage of obstructive, restrictive, mixed, and nonspecific lung function impairments identified using the 2 sets of reference equations. Secondary outcomes were differences in severity of these impairments.

Results

PFTs were interpreted from 2722 Black (686 men [25.4%]; mean [SD] age, 51.8 [13.9] years) and 5709 White (2654 men [46.5%]; mean [SD] age, 56.4 [14.3] years) individuals. Among Black individuals, replacing the race-specific reference equations with the race-neutral reference equations was associated with an increase in the prevalence of restriction from 26.8% (95% CI, 25.2%-28.5%) to 37.5% (95% CI, 35.7%-39.3%) and of a nonspecific pattern of impairment from 3.2% (95% CI, 2.5%- 3.8%) to 6.5% (95% CI, 5.6%-7.4%) and no significant change in the prevalence of obstruction (19.9% [95% CI, 18.4%-21.4%] vs 19.5% [95% CI, 18.0%-21.0%]). Among White individuals, replacing the race-specific reference equations with the race-neutral reference equations was associated with a decrease in the prevalence of restriction from 22.6% (95% CI, 21.5%-23.6%) to 18.0% (95% CI, 17.0%-19.0%), a decrease in the prevalence of a nonspecific pattern of impairment from 8.7% (95% CI, 7.9%-9.4%) to 4.0% (95% CI, 3.5%-4.5%), and no significant change in the percentage with obstruction from 23.9% (95% CI, 22.8%-25.1%) to 25.1% (95% CI, 23.9%- 26.2%). The race-neutral reference equations were associated with an increase in severity in 22.8% (95% CI, 21.2%-24.4%) of Black individuals and a decrease in severity in 19.3% (95% CI, 18.2%-20.3%) of White individuals vs the race-specific reference equations.

Conclusions and Relevance

In this cross-sectional study, the use of race-neutral reference equations to interpret PFTs resulted in a significant increase in the number of Black individuals with respiratory impairments along with a significant increase in the severity of the identified impairments. More work is needed to quantify the effect these reference equations would have on diagnosis, referral, and treatment patterns.

Does routine spirometry impact on clinical decisions and patient-related outcome measures of children seen in respiratory clinics: an open-label randomised controlled trial

INTRODUCTION

There is limited evidence on the efficacy of using spirometry routinely in paediatric practice for improving outcomes.

OBJECTIVE

To determine whether the routine use of spirometry alters clinical decisions and patient-related outcome measures for children managed by respiratory paediatricians.

METHODS

We undertook a parallel open-label randomised controlled trial involving children (aged 4-18 years) able to perform spirometry in a specialist children's hospital in Australia. Children were randomised to either routine use of spirometry (intervention) or clinical review without use of spirometry (control) for one clinic visit. The primary outcomes were the (a) proportion of children with 'any change in clinical decisions' and (b) 'change score' in clinical decisions. Secondary outcomes were change in patient-related outcome measures assessed by State-Trait Anxiety Inventory (STAI) and Parent-Proxy QoL questionnaire for paediatric chronic cough (PC-QoL).

RESULTS

Of 136 eligible children, 106 were randomised. Compared with controls, the intervention group had significantly higher proportion of children with 'any change in clinical decisions' (n=54/54 (100%) vs n=34/52 (65.4%), p<0.001) and higher clinical decision 'change score' (median=2 (IQR 1-4) vs 1 (0-2), p<0.001). Also, improvement was significantly greater in the intervention group for overall STAI score (median=-5 (IQR -10 to -2) vs -2.5 (-8.5, 0), p=0.021) and PC-QoL social domain (median=3 (IQR 0 to 5) vs 0 (-1, 1), p=0.017).

CONCLUSION

The routine use of spirometry in children evaluated for respiratory issues at clinical outpatient review is beneficial for optimising clinical management and improving parent psychosocial well-being.

REGISTRATION

Australia and New Zealand Clinical Trials Registry ACTRN12619001686190.

Prematurity-associated wheeze: current knowledge and opportunities for further investigation

Prematurity-associated wheeze is a common complication of preterm birth, with significant impact on the health and healthcare utilization of former preterm infants. This wheezing phenotype remains poorly understood and difficult to predict. This review will discuss the current state of the literature on prematurity-associated wheeze. We will discuss etiology and pathophysiology, and offer two conceptual models for the pathogenesis of this complex condition. This review will also identify current methods of ascertainment, and discuss the strengths and limitations of each. We will explore research-backed approaches to prevention and management, and finally suggest both pre-clinical and clinical avenues for investigation. An in-depth understanding of prematurity-associated wheeze will aid clinicians in its diagnosis and management, and inspire scientists to pursue much-needed further study into causes and prevention of this common and impactful condition. IMPACT: There is no recent, concise review on the current state of research on prematurity-associated wheeze, which is a rapidly evolving area of study. This article highlights causal models of wheeze, methods of ascertainment, management strategies for the clinician, and opportunities for further research for the physician scientist.

Does the routine use of spirometry improve clinical outcomes in children?-A systematic review

Spirometry provides a quantitative measure of lung function and its use is recommended as an adjunct to enhance pediatric respiratory healthcare in many clinical practice guidelines. However, there is limited evidence confirming the benefits (or otherwise) of using spirometry from either clinician or patient perspectives. This systematic review aimed to determine the impact of spirometry on change in clinical decision making and patient-reported outcome measures. We searched PubMed, Embase, Cochrane Central Register of Controlled Trials, www.clinicaltrials.gov, and World Health Organization International Clinical Trials Registry Platform, from inception to July 2021. We included randomized controlled trials (RCTs) comparing the use versus non-use of spirometry during standard clinical review in children aged <18 years with respiratory problems in clinics. We used Cochrane methodology. The search identified 3475 articles; 8 full-text articles were reviewed but only 1 study fulfilled the inclusion criteria. The single study involved two cluster RCTs of spirometry for children with asthma in general practice. The included study did not find any significant intergroup difference at the 12-month follow-up for asthma-related quality-of-life and clinical endpoints. However, the findings were limited by methodological weaknesses and high risks of bias. With a paucity of data, the clinical benefits of spirometry remain unclear. Thus, there is a clear need for RCTs that provide high-quality evidence to support the routine use of spirometry in children with suspected or known lung disease. Pending the availability of better evidence, we recommend that clinicians adhere to the current clinical practice recommendations.

Impact of using spirometry on clinical decision making and quality of life in children: protocol for a single centre randomised controlled trial

INTRODUCTION

Although spirometry has been available for decades, it is underused in paediatric practice, other than in specialist clinics. This is unsurprising as there is limited evidence on the benefit of routine spirometry in improving clinical decision making and/or outcomes for children. We hypothesised that using spirometry for children being evaluated for respiratory diseases impacts on clinical decision making and/or improves patient-related outcome measures (PROMs) and/or quality of life (QoL), compared with not using spirometry.

METHODS AND ANALYSIS

We are undertaking a randomised controlled trial (commenced in March 2020) that will include 106 children (aged 4-18 years) recruited from respiratory clinics at Queensland Children's Hospital, Australia. Inclusion criteria are able to perform reliable spirometry and a parent/guardian who can complete questionnaire(s). Children (1:1 allocation) are randomised to clinical medical review with spirometry (intervention group) or without spirometry (control group) within strata of consultation status (new/review), and cough condition (present/absent). The primary outcome is change in clinical decision making. The secondary outcomes are change in PROM scores, opinions regarding spirometry and degree of diagnosis certainty. Intergroup differences of these outcomes will be determined by χ2 test or unpaired t-test (or Mann-Whitney if not normally distributed). Change in outcomes within the control group after review of spirometry will also be assessed by McNemar's test or paired t-test/Wilcoxon signed-rank test.

ETHICS AND DISSEMINATION

The Human Research Ethics Committee of the Queensland Children's Hospital approved the study. The trial results will be disseminated through conference presentations, teaching avenues and publications.

TRIAL REGISTRATION NUMBER

ACTRN12619001686190; Pre-results.

Pictorial versus written asthma action plans for youth: initial impact on regimen knowledge, medication adherence, symptom control, and family satisfaction

OBJECTIVE

Asthma action plans (AAP) are recommended to guide asthma management. Written AAPs (WAAPs) are under-utilized and can be difficult to understand. Our study designed and tested a simplified pictorial AAP (PAAP). We hypothesized that better outcomes would be obtained for youth with the PAAP.

METHODS

One hundred and sixty-nine (169) youth (aged 8-17; AAP-naïve) were screened for this pilot, 2-arm randomized controlled trial. Feasibility, usability and preliminary efficacy of PAAP compared to a WAAP, for improving outcomes (inhaled corticosteroid (ICS) adherence, symptom control, AAP knowledge, AAP satisfaction) were assessed quantitatively. Youth received an AAP from their physician after completing baseline measures and completed measures at three additional time points (1-, 3-, and 6-month).

RESULTS

Forty-five youth were recruited (PAAP = 22; WAAP = 23). Youth AAP knowledge was higher for the PAAP group compared to the WAAP group (p = .017). ICS adherence did not differ between groups, over time, or based on prescribed dosing; however, for WAAP participants, adherence was lower with a higher daily prescription (4 puffs) relative to a lower dose (p = .006). Symptom control improved with both AAPs, but the change was not statistically significant. Lung function did not change significantly by AAP type or time, and literacy variables were not related significantly to outcomes. Youth satisfaction with AAP improved significantly for the PAAP group compared to the WAAP group (p = .03).

CONCLUSIONS

Higher AAP knowledge and satisfaction among youth in the PAAP group suggests that structured education from a physician using a PAAP is beneficial. Intervention and study design insights gained will guide future research.

The 'clinically significant' bronchodilator responsiveness (BDR) in children: a comparative study between six definitions of scholarly societies and a mini-review

Objective: To compare the percentages of children with and without airway obstruction (obstructive and non-obstructive groups, respectively) presenting a 'clinically significant' BDR according to the following definitions: GINA: FEV₁ increase >12% predicted (∆_Predicted), ATS/ERS: FEV₁ increase ≥12% initial (∆_Initial) and ∆FEV₁ absolute (∆) ≥200 ml and/or ∆FVC_Initial ≥12% and ∆FVC ≥200 ml, British thoracic society (BTS): ∆FEV_1Initial ≥12%, National asthma education and prevention program (NAEPP): ∆FEV_1Initial ≥12% and ∆FEV₁ > 200 ml, Group of research on advances in pediatric pneumology: ∆FEV_1Initial ≥12% or ∆PEF_Initial ≥20%, and South African thoracic society (SATS): ∆FEV_1Initial ≥12% or ∆FEV₁ >200 ml and/or ∆FVC_Initial ≥12% or ∆FVC >200 ml.Methods: This was a multicenter comparative study involving 278 children aged 6 to16 years: obstructive group (FEV₁/FVC < lower-limit-of-normal, n = 116) and non-obstructive group (FEV₁/FVC ≥ lower-limit-of-normal, n = 162). Spirometry was performed before/after a bronchodilator test. The Cochrane Q test was used to compare the percentage of responders according to the six definitions.Results: The percentages of responders among the obstructive [ranging from 51.72 (NAEPP) to 74.14% (SATS)] and the non-obstructive [ranging from 0.62 (NAEPP, BTS) to 8.64% (SATS)] groups were definition-dependent.Conclusion: In children, a 'clinically significant' BDR is definition-dependent.

Development of Oral Chewable Tablets Containing Montelukast Nanoparticles for the Treatment of Childhood Asthma: Preclinical Study in Animal Model

The aim of the present study was to formulate oral chewable tablets of Montelukast (MTL) in the form of nanoparticles (NP’s). The MTL loaded NP’s were formulated by ionotropic external gelation method using tripolyphosphate (TPP) as crosslinking agent and Tween 60 as surfactant. NP’s were characterized for drug loading, encapsulation efficiency, surface morphology, saturation solubility, particle size, zeta potential and polydispersity index. The optimized NP formulation was used for development of chewable tablets using direct compression method. The prepared tablets were characterized for disintegration test, dissolution, thickness, hardness, friability and assay. The optimized formulation was evaluated in asthamatic animals to demonstrate the efficiency in asthama. The encapsulation efficiency of NP’s was found between 91.24 to 98.21% while drug loading was in the range of 10.09–14.25%. All formulations were found of nanosized in nature (110 to 200 nm) with excellent zeta potential (20.12 to 22.27 mV). PDI of all NP formulations were found within acceptable limit (less than 0.3). The nanoparticles were found spherical in shape with smooth surface. The saturation solubility of MTL was enhanced nearly 10 times (92 mg/ml) as compared to pure MTL saturation solubility. All physical parameters of the tablets were found within range. The optimized tablets showed disintegration time of 20 sec while other formulations showed DT in the rage of 35–57 sec. Tab1 (Optimized formulation) showed almost 100% MTL release from chewable tablets within the period of 30 min. Reduction in lung resistance (RI) was found in animals treated with Tab1. This reduction in RI was found nearly two fold and three fold as compare to MTL treated and control group animals. These observations clearly support the efficacy of chewable tablets containing nanoparticulate MTL in asthmatic animals.

Priorities for future research into asthma diagnostic tools: A PAN-EU consensus exercise from the European asthma research innovation partnership (EARIP)

The diagnosis of asthma is currently based on clinical history, physical examination and lung function, and to date, there are no accurate objective tests either to confirm the diagnosis or to discriminate between different types of asthma. This consensus exercise reviews the state of the art in asthma diagnosis to identify opportunities for future investment based on the likelihood of their successful development, potential for widespread adoption and their perceived impact on asthma patients. Using a two-stage e-Delphi process and a summarizing workshop, a group of European asthma experts including health professionals, researchers, people with asthma and industry representatives ranked the potential impact of research investment in each technique or tool for asthma diagnosis and monitoring. After a systematic review of the literature, 21 statements were extracted and were subject of the two-stage Delphi process. Eleven statements were scored 3 or more and were further discussed and ranked in a face-to-face workshop. The three most important diagnostic/predictive tools ranked were as follows: "New biological markers of asthma (eg genomics, proteomics and metabolomics) as a tool for diagnosis and/or monitoring," "Prediction of future asthma in preschool children with reasonable accuracy" and "Tools to measure volatile organic compounds (VOCs) in exhaled breath."

Assessing Exercise-Induced Bronchoconstriction in Children; The Need for Testing

Objective: Exercise-induced bronchoconstriction (EIB) is a specific morbidity of childhood asthma and a sign of insufficient disease control. EIB is diagnosed and monitored based on lung function changes after a standardized exercise challenge test (ECT). In daily practice however, EIB is often evaluated with self-reported respiratory symptoms and spirometry. We aimed to study the capacity of pediatricians to predict EIB based on information routinely available during an outpatient clinic visit. Methods: A clinical assessment was performed in 20 asthmatic children (mean age 11.6 years) from the outpatient clinic of the MST hospital from May 2015 to July 2015. During this assessment, video images were made. EIB was measured with a standardized ECT performed in cold, dry air. Twenty pediatricians (mean years of experience 14.4 years) each evaluated five children, providing 100 evaluations, and predicted EIB severity based on their medical history, physical examination, and video images. EIB severity was predicted again after additionally providing baseline spirometry results. Results: Nine children showed no EIB, four showed mild EIB, two showed moderate, and five showed severe EIB. Based on clinical information and spirometry results, pediatricians detected EIB with a sensitivity of 84% (95% CI 72-91%) and a specificity of 24% (95% CI 14-39%).The agreement between predicted EIB severity classifications and the validated classifications after the ECT was slight [Kappa = 0.05 (95% CI 0.00-0.17)]. This agreement still remained slight when baseline spirometry results were provided [Kappa = 0.19 (95% CI 0.06-0.32)]. Conclusion: Pediatricians' prediction of EIB occurrence was sensitive, but poorly specific. The prediction of EIB severity was poor. Pediatricians should be aware of this in order to prevent misjudgement of EIB severity and disease control.

Misdiagnosis of asthma in schoolchildren

BACKGROUND

A correct diagnosis of asthma is the cornerstone of asthma management. Few pediatric studies have examined the accuracy of physician-diagnosed asthma.

OBJECTIVES

We determined the accuracy of parent reported physician-diagnosed asthma in children sampled from a community cohort.

METHODS

Nested case-control study that recruited 203 children, aged 9-12, from a community-based sample. Three groups were recruited: asthma cases had a parental report of physician-diagnosed asthma, symptomatic controls had respiratory symptoms without a diagnosis of asthma, and asymptomatic controls had no respiratory symptoms. All participants were assessed and assigned a clinical diagnosis by one of three study physicians, and then completed spirometry, methacholine challenge, and allergy skin testing. The reference standard of asthma required a study physician's clinical diagnosis of asthma and either reversible bronchoconstriction or a positive methacholine challenge. Diagnostic accuracy, sensitivity and specificity were calculated for parent-reported asthma diagnosis compared to the reference standard.

RESULTS

One hundred two asthma cases, 52 controls with respiratory symptoms but no asthma diagnosis, and 49 asymptomatic controls were assessed. Physician agreement for the diagnosis of asthma was moderate (kappa 0.46-0.81). Compared to the reference standard, 45% of asthma cases were overdiagnosed and 10% of symptomatic controls were underdiagnosed. Parental report of physician-diagnosed asthma had 75% sensitivity and 92% specificity for correctly identifying asthma.

CONCLUSIONS

There is significant misclassification of childhood asthma when the diagnosis relies solely on a clinical history. This study highlights the importance of objective testing to confirm the diagnosis of asthma. Pediatr Pulmonol. 2017;52:293-302. © 2016 Wiley Periodicals, Inc.

Differences in spirometry values between U.S. children 6-11 years and adolescents 12-19 years with current asthma, 2007-2010

BACKGROUND

National Asthma Education and Prevention Program (NAEPP) guidelines recommend that periodic spirometry be performed in youth with asthma. NAEPP uses different spirometry criteria to define uncontrolled asthma for children (6-11 years) and adolescents (12+ years).

OBJECTIVE

To describe differences in spirometry between U.S. children and adolescents with current asthma.

METHODS

We examined cross-sectional spirometry data from 453 U.S. youth with current asthma age 6-19 years from the 2007-2010 National Health and Nutrition Examination Surveys. The main outcomes were percentage predicted forced expiratory volume at 1 sec (FEV1%) ≤80 and the ratio of FEV1 to forced vital capacity (FEV1/FVC) ≤0.80. We also examined the prevalence of youth with spirometry values consistent with uncontrolled asthma, using NAEPP age-specific criteria, defined for children aged 6-11 years as FEV1% ≤80 or FEV1/FVC ≤0.80, and for adolescents aged 12-19 years as FEV1% ≤80.

RESULTS

Children 6-11 years and adolescents 12-19 years did not differ in prevalence of FEV1% ≤80 (10.1% vs. 9.0%) or FEV1/FVC ≤0.80 (30.6% vs. 29.8%). However, based on the NAEPP age-specific criteria, 33.0% of children 6-11 years and 9.0% of adolescents 12-19 years had spirometry values consistent with uncontrolled asthma (P < 0.001).

CONCLUSION

Children 6-11 years and adolescents 12-19 years with current asthma did not differ in the percentage with FEV1% ≤80 or FEV1/FVC ≤0.80. However, the percent of children and adolescents with spirometry values consistent with uncontrolled asthma did differ. The difference appears to stem mainly from the different spirometry criteria for the two age groups.

Mismatch between asthma symptoms and spirometry: implications for managing asthma in children

OBJECTIVES

To examine the concordance between spirometry and asthma symptoms in assessing asthma severity and beginning therapy by the general pediatrician.

STUDY DESIGN

Between 2008 and 2012, spirometry testing was satisfactorily performed in 894 children (ages 5-19 years) whose asthma severity had been determined by their pediatrician using asthma guideline-based clinical criteria. Spirometry-determined asthma severity using national asthma guidelines and clinician-determined asthma severity were compared for concordance using weighted Kappa coefficients.

RESULTS

Thirty percent of participants had clinically determined intermittent asthma; 32%, 33%, and 5% had mild, moderate, and severe, persistent asthma, respectively. Increasing disease severity was associated with decreases in the forced expiratory volume in 1 second/forced vital capacity (FVC) ratio (P < .001), the forced expiratory volume in 1 second/FVC% predicted (P < .0001), and the FVC% predicted (P < .01). In 319 children (36%), clinically determined asthma severity was lower than spirometry-determined severity. Concordance was 0.16 (95% CI 0.10, 0.23), and when adjusted for bias and prevalence, was 0.20 (95% CI 0.17, 0.23). When accounting for age, sex, exposure to smoke, and insurance type, only spirometry-determined asthma severity was a significant predictor of agreement (P < .0001), with worse agreement as spirometry-determined severity increased.

CONCLUSIONS

Concordance between spirometry and asthma symptoms in determining asthma severity is low even when guideline-based clinical assessment tools are used. Because appropriate therapy reduces asthma morbidity and is guided by disease severity, results from spirometry testing could better guide pediatricians in determining appropriate therapy for their patients with asthma.

Spirometry use in children hospitalized with asthma

Asthma is the most common chronic disorder of childhood and continues to be a leading cause of pediatric hospital admission. The National Asthma Education and Prevention Program (NAEPP) recommends that spirometry be obtained for asthma patients upon hospital admission, after bronchodilation during the acute phase of asthma symptoms, and at least one additional time before discharge from the hospital. The objectives of this study were to describe the use of spirometry in children hospitalized with asthma and to determine association of pulmonary function with future exacerbations. A retrospective cohort study design was utilized involving review of medical records of children ≥5 years old admitted with asthma to Cincinnati Children's Hospital Medical Center from September 1, 2009 to March 31, 2011. Hospitalization or emergency department (ED) visits were identified by the ICD-9-CM codes of having either a primary diagnosis of asthma (493) or a respiratory illness (460-496) plus a secondary diagnosis of asthma. Asthma re-exacerbation was defined as either having an ED visit or hospitalization for asthma that occurred within 3 months after the index hospitalization. All spirometries were performed in a pediatric pulmonary function laboratory. Among 1,037 admissions included in this study, 89 (8.6%) had spirometry that was recommended by a consulting asthma specialist and usually performed on the day of discharge. Spirometries for forty-five of these patients (54.9%) met all acceptability and repeatability criteria of the American Thoracic Society. Patients who performed acceptable spirometry were significantly older (12.4 ± 3.8 vs. 10.7 ± 3.0 years; P = 0.041). The average forced expiratory volume in the first second (FEV1 ) was 84.4 ± 19.7% predicted; forced vital capacity (FVC) was 98.1 ± 16.0% predicted; FEV1 /FVC was 74.6 ± 9.6%; forced expiratory flow at 25-75% (FEF25-75 ) was 61.2 ± 30.1% predicted. Ten patients (22%) who performed spirometry developed a re-exacerbation. Patients with versus without re-exacerbation had significantly lower FEV1 /FVC (P = 0.027) and FEF25-75 (P = 0.031). Nevertheless, separate logistic regression models found that FEV1 /FVC and FEF25-75 were not associated with re-exacerbation when adjusted for age and length-of-stay. We found that few children admitted with asthma had spirometry as recommended in the NAEPP guidelines unless recommended by specialists and both lower lung function (FEV1 /FVC and FEF25-75 ) and history of more frequent and more recent prior health-care utilization for asthma were associated with repeat asthma exacerbation. However, the value of performing spirometry on asthmatic children prior to hospital discharge remains unclear and will require prospective study.

Physician specialty influences important aspects of pediatric asthma management

BACKGROUND

Physician training influences patient care.

OBJECTIVE

To compare asthma management and change in the percentage predicted FEV1 among pediatric physician specialties.

METHODS

A retrospective cohort of children 6 years of age or older, seen in a multidisciplinary asthma clinic between 2009 and 2010, and followed to 2012, was completed to examine differences in asthma outcomes by specialty (2 pediatricians, 3 pediatric allergists, 5 pediatric respirologists). Univariate analyses compared investigation, including allergy testing (skin prick or RAST), comorbid conditions, and prescription by specialty. Multivariate regression, which controlled for random effect of the individual physician, examined specialty differences for prescribed inhaled corticosteroids (ICS) and changes in percentage predicted FEV1.

RESULTS

More than 56% of the patients (309/548) were seen by pediatric respirologists, 26% by pediatric allergists, and 18% by pediatricians. Physician specialty influences investigation requested, comorbid diagnoses, treatment, and improvement in FEV1. Pediatric allergists' patients had more allergy tests, were more likely to be diagnosed with allergic rhinitis and, consequently, were more likely to be prescribed nasal steroids than pediatricians and pediatric respirologists. Pediatricians were less likely to prescribe ICS (odds ratio 0.39 [95% CI, 0.15-0.96]; P < .05) than pediatric allergists, with the greatest difference in ICS prescription among children with a percentage predicted FEV1 ≥ 80%. Improvement in FEV1 among children who received care with pediatric allergists was higher than those seen by pediatricians (13%; P < .001) and pediatric respirologists (8%; P = .005).

CONCLUSIONS

Patient management domains with the greatest room for discretion (investigations, comorbid diagnoses, and treatment with ICS among children with normal lung function) are most heavily influenced by physician specialty. These results have implications for asthma management at the patient level and in future practice guidelines.

Spirometry in children

Respiratory disorders are responsible for considerable morbidity and mortality in children. Spirometry is a useful investigation for diagnosing and monitoring a variety of paediatric respiratory diseases, but it is underused by primary care physicians and paediatricians treating children with respiratory disease. We now have a better understanding of respiratory physiology in children, and newer computerised spirometry equipment is available with updated regional reference values for the paediatric age group. This review evaluates the current literature for indications, test procedures, quality assessment, and interpretation of spirometry results in children. Spirometry may be useful for asthma, cystic fibrosis, congenital or acquired airway malformations and many other respiratory diseases in children. The technique for performing spirometry in children is crucial and is discussed in detail. Most children, including preschool children, can perform acceptable spirometry. Steps for interpreting spirometry results include identification of common errors during the test by applying acceptability and repeatability criteria and then comparing test parameters with reference standards. Spirometry results depict only the pattern of ventilation, which may be normal, obstructive, restrictive, or mixed. The diagnosis should be based on both clinical features and spirometry results. There is a need to encourage primary care physicians and paediatricians treating respiratory diseases in children to use spirometry after adequate training.

Effect of spirometry and medical review on asthma control in patients in general practice: a randomized controlled trial

BACKGROUND AND OBJECTIVE

Although guidelines for asthma emphasize the importance of spirometry for continuity and evaluation of care, it is underused in general practice. The objective of this study was to investigate the effect of spirometry and medical review on asthma control in general practice over 12 months.

METHODS

Patients were recruited through 31 practices, which were randomly allocated to one of three groups: Group A had 3-monthly spirometry with medical review, Group B spirometry only before and after the trial, and Group C usual care. Asthma control data were analysed by intention to treat using non-parametric tests and logistic regression models fitted to allow for confounders, repeated measures and clustering by practice.

RESULTS

The trial was completed by 195 patients (Group A 69, Group B 78, Group C 48). Asthma control improved in all groups during the 12 months trial, most impressively in Group A (odds ratio per 3 months = 1.27, 95% confidence interval: 1.08-1.49, P = 0.004), but the difference between the groups' respective 3-monthly changes was not significant. At 6 months, asthma control in Group A had increased more from baseline than in Groups B + C (P = 0.006).

CONCLUSIONS

Regular spirometry with medical review was associated with improved asthma control in general practice patients, while there was less improvement in either the spirometry only or usual care group. The mechanisms of this improvement may include appropriate adjustment of medication and improved compliance.

Pulmonary function testing in the diagnosis of asthma: a population study

BACKGROUND

Asthma is a common chronic respiratory condition, the diagnosis of which depends on symptoms and objective evidence of variable airflow obstruction or airway hyperresponsiveness. The proportion of people who have had objective pulmonary function testing around the time of diagnosis and factors associated with receiving testing are not well understood.

METHODS

A retrospective cohort study was conducted using the health administrative data of all individuals aged 7 years and older with newly physician-diagnosed asthma living in Ontario, Canada between 1996 and 2007. Receipt of pulmonary function testing in the peridiagnostic period was determined and examined across patient sociodemographic and clinical factors.

RESULTS

Only 42.7% (95% CI, 42.6%-42.9%) of the 465,866 Ontarians newly diagnosed with asthma received pulmonary function testing between 1 year prior and 2.5 years following the time of diagnosis. In adjusted analyses, individuals 7 to 9 years old and those 70 years or older were less likely to receive testing than younger adults, individuals in the lowest neighborhood income quintile were less likely to receive testing than those in the highest, and individuals seeing a medical specialist were more likely to receive testing than those seeing only a general practitioner.

CONCLUSIONS

Less than one-half of patients with new physician-diagnosed asthma in Ontario, Canada received objective pulmonary function testing around the time of diagnosis. Further study is needed to determine why more pulmonary function testing is not being used to diagnose asthma and how barriers to its appropriate use can be overcome.

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 (FEV(1)) 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 FEV(1)% 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.

Lung function measurement in the assessment of childhood asthma: recent important developments

PURPOSE OF REVIEW

To present three clinically important developments related to the utilization of pulmonary function to objectively assess the asthmatic child.

RECENT FINDINGS

The new asthma guidelines (2007) have added the forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio to the FEV1 as spirometric criteria for classifying asthma. Although a better indicator of airway obstruction, it has not clearly been shown to correlate with clinical criteria. The normal cut point for the ratio used in the guidelines of 85% for children may be too high, and compared to the lower limits of normal of 80%, could result in unnecessary treatment in some children. The bronchodilator response (BDR) phenotype reflects airway lability and has been associated with biomarkers of inflammation and responsiveness to inhaled corticosteroids as well as predicting long-term outcomes. Several studies have shown improved spirometric techniques in preschoolers as well as defining normal values in this age group. Impulse oscillometry (IOS), which is less demanding than spirometry, has been shown to identify asthmatic preschoolers in some cases better than spirometry and possibly identifying obstruction in the peripheral airways. It may also be a more useful test than spirometry in evaluating long-term drug studies.

SUMMARY

In addition to the FEV1/FVC ratio to detect airway obstruction, the BDR phenotype would appear to give important additional information regarding airway lability and inflammation, and should be included as routine spirometry. IOS is a promising test to identify asthmatic preschoolers, but more studies are needed to determine exactly what it measures and what constitutes normal values.

The use of spirometry in a primary care setting

Objective:

To determine the use of spirometry in family practice, internal medicine, and pediatric outpatient settings.

Methods:

Data were collected from 45 outpatient offices in the central Pennsylvania area via phone survey that asked a set of four questions: 1) Do you have spirometry in your office? 2) Do you use spirometry for asthma patients? 3) In what situation do you use spirometry for? 4) Do you use spirometry more for chronic obstructive pulmonary disease (COPD) or asthma?

Results:

It was found that pediatricians used spirometry 66% of the time, family practitioners 47% of the time, and internal medicine practitioners 60% of the time. Of those who did not use spirometry, 94% stated that they refer to a hospital if they required spirometry and 6% referred to subspecialists if the patient required spirometry. 10% of pediatricians performed the test on each asthma visit, otherwise the others used it only for exacerbations or as a baseline. No internists used spirometry regularly for asthma patients, and 22% used it more for COPD. In family practice only 14% used spirometry routinely at each visit for asthma patients.

Conclusions:

Pediatricians used spirometry more often in the outpatient setting than other specialists, followed closely by internal medicine physicians. Family practice physicians were the least likely to use spirometry. Multiple barriers seemed to prevent routine use of spirometry, but no one barrier accounted for the majority.

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.

Value of the bronchodilator response in assessing controller naïve asthmatic children

OBJECTIVE

To define the bronchodilator response (BDR) cutoff point that best identified asthma to determine the frequency of abnormal spirometry results across severity.

STUDY DESIGN

Controller naïve children were evaluated with clinical criteria alone to establish a diagnosis of asthma and severity classification, then compared with the BDR, which was calculated as the percent change from the initial forced expiratory volume in 1 second. Receiver operator characteristic analysis determined the cutoff point for asthma diagnosis that gave the best combination of sensitivity and specificity.

RESULTS

Children with asthma (n = 346) and 51 children without asthma, aged 4 to 17 years, who met entry criteria for spirometry were identified. The mean BDR in asthmatics was 8.6% (95% CI, 7.5-9.8), compared with 2.2% (95% CI, 0.2-4.3) for non-asthmatics (P < .001). A BDR > or = 9% best differentiated these populations with a sensitivity rate of 42.5% and a specificity rate of 86.3%. Abnormal spirometry results, defined as a BDR > or = 9%, a forced expiratory volume in 1 second < 80% predicted, or both, ranged from 44.4% for mild intermittent bronchial asthma to 57.0% for severe persistent bronchial asthma.

CONCLUSION

Spirometric criteria that include BDR can potentially identify children who have clinically mild asthma and might benefit from controller therapy.