ABSTRACT
Las guías ATS/ERS recomiendan utilizar valores de referencia nacionales para la interpretación de la espirometría. En 2014 se publicaron valores de referencia en población general chilena adulta, que difieren de los de Knudson actualmente en uso. Sin embargo, la mayoría de los laboratorios de función pulmonar siguen utilizando estas últimas ecuaciones. En 2012 se publicaron las ecuaciones multi-étnicas de la Global Lung Function Initiative (GLI) a fin de estandarizar mundialmente la interpretación de los exámenes de función pulmonar Nuestro objetivo fue comparar la concordancia de los informes espirométricos utilizando las ecuaciones más usadas en Chile versus las GLI. Métodos: Se comparó la concordancia en interpretación del patrón espirométrico (normal, obstructivo y restrictivo) y el grado de alteración, entre GLI con Gutiérrez 2014, con Knudson, y con NHANES III según las recomendaciones de la Sociedad Chilena de Enfermedades Respiratorias, a través del coeficiente de concordancia Kappa (K). Se estudiaron 315 sujetos mayores de 40 años (55% mujeres, edad: 59,3 ± 9,2 años), fumadores o ex fumadores, sanos o con EPOC, sometidos a una espirometría con broncodilatador como parte de un reconocimiento respiratorio. Se graficaron las diferencias utilizando el método de Bland-Altman. Resultados: La concordancia para patrón entre GLI con Gutiérrez 2014, con Knudson y con NHANES III fue buena (K = 0,73; 0,71 y 0,77 respectivamente), al igual que para patrón y grado de alteración (K = 0,68; 0,67 y 0,76 respectivamente). Conclusiones: Encontramos una buena concordancia entre las ecuaciones más usadas en Chile y las de GLI, en una muestra que incluyó adultos, fumadores, ex fumadores sanos y enfermos.
ATS/ERS recommend the use of national reference values for the interpretation of spirometry. Reference values were published (2014) in general adult Chilean population, which are different from those of Knudson currently in use. However, most pulmonary function laboratories continue to use these latter equations. Multi-ethnic Global Lung Function Initiative (GLI) equations were published (2012) in order to standardize the interpretation of pulmonary function tests worldwide. Our objective was to evaluate the agreement in the spirometric reports between the most used equations in Chile with those from GLI. Methods: We compared the agreement in the interpretation of the spirometric pattern (normal, obstructive and restrictive) and the degree of alteration between GLI with Gutiérrez 2014, with Knudson and with NHANES III according to recommendations of the Chilean Society of Respiratory Diseases, through the Kappa concordance coefficient (K). The sample correspond to 315 adults over 40 years of age (55% women, 59.3 ± 9.2 years-old), smokers or ex-smokers, healthy or with COPD, who underwent spirometry with a bronchodilator as part of a respiratory check-up. Differences were plotted using the Bland-Altman method. Results: agreement for pattern between GLI with Gutiérrez 2014, with Knudson and with NHANES III was good (K = 0.73, 0.71 and 0.77 respectively) and also was good for the pattern and degree of alteration (K = 0.68, 0.67 and 0.76 respectively). Conclusions: We found a good agreement between the equations most used in Chile and those from the GLI, for a sample that includes subjects with and without lung disease, smokers and ex-smokers.
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Aged, 80 and over , Spirometry/methods , Spirometry/standards , Lung/physiology , Models, Theoretical , Reference Values , Respiratory Function Tests/methods , Respiratory Function Tests/standards , Societies, Medical , Vital Capacity/physiology , Forced Expiratory Volume/physiologyABSTRACT
ABSTRACT Objective: To generate reference values for spirometry in Brazilian children 3-12 years of age and to compare those values with the values employed in the equations currently in use in Brazil. Methods: This study involved healthy children, 3-12 years of age, recruited from 14 centers (primary data) and spirometry results from children with the same characteristics in six databases (secondary data). Reference equations by quantile regressions were generated after log transformation of the spirometric and anthropometric data. Skin color was classified as self-reported by the participants. To determine the suitability of the results obtained, they were compared with those predicted by the equations currently in use in Brazil. Results: We included 1,990 individuals from a total of 21 primary and secondary data sources. Of those, 1,059 (53%) were female. Equations for FEV1, FVC, the FEV1/FVC ratio, FEF between 25% and 75% of the FVC (FEF25-75%) and the FEF25-75%/FVC ratio were generated for white-, black-, and brown-skinned children. The logarithms for height and age, together with skin color, were the best predictors of FEV1 and FVC. The reference values obtained were significantly higher than those employed in the equations currently in use in Brazil, for predicted values, as well as for the lower limit of normality, particularly in children with self-reported black or brown skin. Conclusions: New spirometric equations were generated for Brazilian children 3-12 years of age, in the three skin-color categories defined. The equations currently in use in Brazil seem to underestimate the lung function of Brazilian children 3-12 years of age and should be replaced by the equations proposed in this study.
RESUMO Objetivo: Gerar valores de referência para espirometria em crianças brasileiras de 3-12 anos de idade e comparar os resultados obtidos com as equações em uso no Brasil. Métodos: Foram incluídas crianças sadias de 3-12 anos recrutadas em 14 centros (dados primários) e resultados de espirometria de crianças com as mesmas características de seis bancos de dados (dados secundários). As equações quantílicas foram geradas após transformações logarítmicas dos dados espirométricos e antropométricos. A classificação por cor da pele foi autodeclarada. Os resultados obtidos foram comparados com os previstos nas equações em uso no Brasil para testar sua adequação. Resultados: Foram incluídos 1.990 indivíduos de 21 fontes de dados primários e secundários, sendo 1.059 (53%) do sexo feminino. Equações para VEF1, CVF, VEF1/CVF, FEF25-75% e FEF25-75%/CVF foram geradas para crianças brancas e para crianças negras e pardas. Os logaritmos da estatura e da idade e a cor da pele foram os melhores preditores para VEF1 e CVF. Os resultados obtidos foram significativamente maiores do que as estimativas geradas pelas equações em uso no Brasil, tanto para valores previstos quanto para o limite inferior da normalidade, particularmente em crianças negras e pardas. Conclusões: Novas equações espirométricas foram geradas para crianças brasileiras de 3-12 anos de cor branca, negra e parda. As equações atualmente em uso no Brasil parecem subestimar a função pulmonar de crianças brasileiras menores de 12 anos de idade e deveriam ser substituídas pelas equações propostas neste estudo.
Subject(s)
Humans , Female , Child, Preschool , Child , Spirometry/standards , Vital Capacity/physiology , Reference Values , Spirometry/methods , Brazil , Forced Expiratory Volume/physiology , Predictive Value of TestsABSTRACT
Spirometry is the most commonly used test to evaluate lung function in children and adults. To obtain good quality results, several requirements must be fulfilled: professional capacity of the technician, the quality of the equipment, the patient's collaboration, the use of appropriate reference standards. The purpose of spirometry is to define types of ventilatory alterations of the central and peripheral airways, to evaluate the response to bronchodilators and to guide the presence of restrictive diseases. The new consensus of national and international experts are described, which have been perfecting several aspects of this test.
La espirometría es el examen más comúnmente utilizado para evaluar la función pulmonar en niños y adultos. Para obtener resultados de buena calidad deben cumplirse varios requisitos, desde la capacidad profesional del técnico, calidad de los equipos, colaboración del paciente y utilización de patrones de referencia adecuados. La espirometría tiene como utilidad definir alteraciones ventilatorias obstructivas de vía aérea central y periférica, evaluar respuesta a broncodilatador y orientar al diagnóstico de enfermedades restrictivas. Se describen los nuevos consensos de expertos nacionales e internacionales, los cuales han ido perfeccionando varios aspectos de este examen.
Subject(s)
Humans , Child , Adolescent , Respiratory Physiological Phenomena , Spirometry/standards , Lung Volume Measurements/instrumentation , Quality Control , Reference Values , Spirometry/instrumentation , Calibration , Vital Capacity/physiology , Forced Expiratory Volume/physiology , Maximal Expiratory Flow-Volume Curves , Lung/physiologyABSTRACT
ABSTRACT Objective: To determine the frequency of spirometry in elderly people, by age group, at a pulmonary function clinic, to assess the quality of spirometry in the extremely elderly, and to determine whether chronological age influences the quality of spirometry. Methods: This was a cross-sectional retrospective study evaluating information (spirometry findings and respiratory questionnaire results) obtained from the database of a pulmonary function clinic in the city of Aracaju, Brazil, for the period from January of 2012 to April of 2017. In the sample as a whole, we determined the total number of spirometry tests performed, and the frequency of the tests in individuals ≥ 60 years of age, ≥ 65 years of age, and by decade of age, from age 60 onward. In the extremely elderly, we evaluated the quality of spirometry using criteria of acceptability and reproducibility, as well as examining the variables that can influence that quality, such a cognitive deficit. Results: The sample comprised a total of 4,126 spirometry tests. Of those, 961 (23.30%), 864 (20.94%), 102 (2.47%), and 26 (0.63%) were performed in individuals ≥ 60, ≥ 65, ≥ 86, and ≥ 90 years of age (defined as extreme old age), respectively. In the extremely elderly, the criteria for acceptability and reproducibility were met in 88% and 60% of the spirometry tests (95% CI: 75.26-100.00 and 40.80-79.20), respectively. The cognitive deficit had a negative effect on acceptability and reproducibility (p ≤ 0.015 and p ≤ 0.007, respectively). Conclusions: A significant number of elderly individuals undergo spirometry, especially at ≥ 85 years of age, and the majority of such individuals are able to perform the test in a satisfactory manner, despite their advanced age. However, a cognitive deficit could have a negative effect on the quality of spirometry.
RESUMO Objetivo: Determinar a frequência de idosos que realizaram espirometria num serviço de função pulmonar, e avaliar a qualidade da realização do exame na velhice extrema e se a idade cronológica influencia essa qualidade. Métodos: Estudo transversal retrospectivo utilizando informações (espirometria e questionário respiratório) de um banco de dados de um serviço de função pulmonar em Aracaju (SE) entre janeiro de 2012 e abril de 2017. Com base na amostra geral, determinou-se o número total de espirometrias realizadas em todas as idades, em idosos ≥ 60 anos, ≥ 65 anos, e por década de idade a partir da sexta década. Na velhice extrema, avaliou-se a qualidade da espirometria utilizando critérios de aceitabilidade e reprodutibilidade, e investigaram-se variáveis que influenciam essa qualidade, tal como déficit cognitivo. Resultados: A amostra geral foi composta por 4.126 espirometrias. Dessas, 961 (23,30%), 864 (20,94%), 102 (2,47%) e 26 (0,63%) foram realizadas em idosos com ≥ 60 anos de idade, ≥ 65 anos, ≥ 86 anos e ≥ 90 anos (velhice extrema), respectivamente. Na velhice extrema, os critérios de aceitabilidade e reprodutibilidade foram preenchidos em 88% (IC95%: 75,26-100,00) e 60% (IC95%: 40,80-79,20) das espirometrias, respectivamente. O déficit cognitivo influenciou negativamente a aceitabilidade e a reprodutibilidade (p ≤ 0,015; e p ≤ 0,007, respectivamente). Conclusões: Idosos na velhice extrema são uma realidade atual nos serviços de função pulmonar, e a maioria deles é capaz de realizar espirometrias adequadamente, apesar da idade avançada. O déficit cognitivo influencia negativamente a qualidade da espirometria.
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Aged, 80 and over , Respiratory Tract Diseases/diagnosis , Respiratory Tract Diseases/physiopathology , Spirometry/methods , Spirometry/standards , Lung/physiopathology , Respiratory Tract Diseases/psychology , Spirometry/psychology , Aging/physiology , Comorbidity , Peak Expiratory Flow Rate , Sex Factors , Vital Capacity/physiology , Forced Expiratory Volume/physiology , Cross-Sectional Studies , Reproducibility of Results , Retrospective Studies , Age Factors , Cognitive DysfunctionABSTRACT
INTRODUCCIÓN: La espirometría es el examen más utilizado para evaluar función pulmonar. Para niños pre-escolares actualmente se cuenta con patrones de referencia extranjeros. OBJETIVOS: 1. Medir variables espirométricas en pre-escolares chilenos sanos, 2. Comparar estos resultados con predictivos según GLI (Global Lung Initiative), Eigen (USA) y França (Brasil) y 3. De haber diferencia significativa con éstos, elaborar ecuaciones de referencia. SUJETOS Y MÉTODO: Se distribuyeron encuestas a apoderados de colegios y jardines infantiles de Santiago. Se excluyeron niños con antecedente de prematurez, síntomas asmáticos, enfermedad pulmonar crónica (incluida asma) y enfermedad crónica no respiratoria. La espirometría se realizó según guías ATS/ERS 2007, con equipo MedGraphics, USA. Se registraron antecedentes familiares, ambientales, peso y talla y los valores obtenidos en capacidad vital forzada (CVF), volumen espirado forzado en 0,5, 0,75 y 1 segundo (VEF 05, VEF0 75 y VEFj, respectivamente). RESULTADOS: Se realizaron 276 espirometrías, de las cuales 202 cumplieron criterios de aceptabilidad, 112 mujeres, edad promedio 5,01 ± 0,57 años, talla 108,7 ± 5,6 cm. Al comparar por género, solo hubo diferencia significativa en CVF, siendo superior en hombres. Los valores promedio obtenidos en el grupo total fueron: CVF 1,22 ± 0,22 litros, VEF1 1,16 ± 0,18 litros, VEF075 1,07 ± 0,17 litros. Nuestros parámetros fueron porcentualmente mayores que los predictivos según GLI, Eigen y França, excepto CVF con Eigen, motivo por el cual se construyeron ecuaciones predictivas. CONCLUSIONES: Los valores espirométricos de pre-escolares residentes en Santiago fueron superiores a los valores de referencia extranjeros. Se proponen patrones de referencia que podrían ser utilizados en nuestro medio.
INTRODUCTION: Spirometry is the most commonly used test to evaluate lung function. Foreign refe rence standards are currently available for preschool children. OBJECTIVES: 1. To measure spirometric variables in healthy Chilean preschool children, 2. To compare these results with predictive ones according to GLI (Global Lung Initiative), Eigen (USA) and França (Brazil), and 3. If there is a sig nificant difference with these, to develop reference equations. SUBJECTS AND METHOD: Questionnaires were distributed to parents in several schools and kindergartens in Santiago. Children with a history of prematurity, asthmatic symptoms, chronic lung disease (including asthma), and chronic non respiratory disease were excluded. Spirometry was performed according to ATS/ERS 2007 guideli nes, with MedGraphics equipment, USA. Family and environmental background, weight and height were recorded, as well as values obtained in forced vital capacity (FVC), forced expiratory volume in 0.5, 0.75 and 1 second (FEV0.5, FEV0.75, and FEV1, respectively). RESULTS: 276 spirometries were performed, 202 met acceptability criteria, 112 girls, average age 5.01 ± 0.57 years, height 108.7 ± 5.6 cm. When comparing by gender, there was only a significant difference in FVC, which was higher in boys. The average values obtained in the total group were: FVC 1.22 ± 0.22 liters, FEV1 1.16 ± 0.18 liters, FEV0.75 1.07 ± 0.17 liters. These parameters were higher in percentage than the predictive ones according to GLI, Eigen, and França, except FVC with Eigen, therefore, predictive equations were de veloped. CONCLUSIONS: Spirometric values of preschoolers living in Santiago were higher than foreign reference values. We proposed these reference standards to be used in our country.
Subject(s)
Humans , Male , Female , Child, Preschool , Child , Spirometry/standards , Reference Standards , Reference Values , Chile , Global Health , Healthy VolunteersABSTRACT
La espirometría es una prueba fundamental en la evaluación funcional respiratoria. Actualmente es muy utilizada debido a su bajo costo y aceptable reproducibilidad incluso en niños entre 2 y 6 años de vida. Considerando la importancia de aplicar procedimientos estandarizados para realizar espirometrías, el año 2006 un comité de especialistas en función pulmonar de la Sociedad Chilena de Enfermedades Respiratorias, elaboró un manual de procedimientos para realizar espirometrías. El año 2014 se publicaron ecuaciones de referencia para adultos chilenos y recientemente se han publicado recomendaciones para estandarizar el informe de los resultados de las pruebas de Función Pulmonar por las Sociedades Americana y Europea de Enfermedades Respiratorias ATS/ERS 2017. El objetivo de esta publicación ha sido actualizar el manual de procedimientos ya existente e incluir los nuevos conceptos de espirometrías en preescolares, valores de referencia, formato e interpretación de los informes.
Spirometry is a basic test for assessing pulmonary function. This test is largely used nowadays, because of its low cost and acceptable reproducibility. Its feasibility has been shown even in 2 to 6 year old children. Considering the importance of applying standardized techniques in spirometry, a committee of specialists on pulmonary function from Chilean Respiratory Society, published in 2006 a procedures manual on spirometry. By 2014 new spirometric reference equations for healthy Chilean adults were published and more recently in 2017, the American Thoracic Society and the European Respiratory Society have published recommendations for a standardized pulmonary function report. The aim of this manual is to report international norms performing spirometry, in order to promote their application in clinical and laboratory practice. In addition, this reviewed manual encloses newest concepts on spirometry in preschool children, reference values, and a general assent way for interpreting and reporting spirometric values at clinical and at laboratory work is proposed.
Subject(s)
Humans , Child , Adult , Spirometry/standards , Manuals as Topic , Quality Control , Reference Values , ChileABSTRACT
INTRODUCCIÓN: El pronóstico de los pacientes con fibrosis quística (FQ) ha mejorado en forma notable. La evaluación de la progresión de la enfermedad se basa en la medición del Volumen Espirado al primer segundo (VEF1). OBJETIVOS: 1. Describir volúmenes y flujos espiratorios forzados y comparar su interpretación según diferentes patrones de referencia (Knudson, multiétnicas Global Lung Initiative, Gutiérrez); 2. Comparar evolución de VEF1 según diferentes patrones de referencia; 3. Describir respuesta a broncodilatador. PACIENTES Y MÉTODO: Estudio retrospectivo de fichas clínicas y espirometrías de pacientes con FQ controlados en Hospital Dr. Sótero del Río. Se obtuvo antecedentes demográficos, resultados de prueba de sudor, estudio genético, estudio bacteriológico. Se evaluó respuesta a broncodilatador (salbutamol 400 ugr), considerando significativo un aumento en 12% en el VEF1. El valor de cloro en sudor se obtuvo mediante método de Gibson y Cooke. Se registraron: Capacidad Vital Forzada (CVF), Volumen Espirado al primer segundo (VEF1) y relación VEF1/CVF. Para graficar la progresión del VEF1 en el tiempo y las curvas teóricas de GLI, Knudson y Gutiérrez, se utilizó el software de libre distribución R versión 3.3.1. RESULTADOS: Se incluyeron 14 pacientes, 7 varones, edad entre 6 y 24 años, mediana 15 años, me diana índice de masa corporal (IMC) 18,15 (rango 14,6-23,3), mediana cloro en sudor 76 mEq/l (rango 50,2- 119), 7 pacientes con al menos 1 mutación F508del. Al utilizar fórmulas predictivas multiétnicas y de Gutiérrez, el compromiso de la función pulmonar ocurría con anterioridad en relación al uso de ecuaciones de Knudson. Ninguno de los pacientes presentó respuesta significativa a broncodilatador. CONCLUSIÓN: El grupo de pacientes descritos presenta en su mayoría compromiso funcional respiratorio y no tiene respuesta a broncodilatador. La interpretación del compromiso funcional respiratorio varía según los valores teóricos utilizados.
INTRODUCTION: The prognosis of patients with cystic fibrosis (CF) has remarkably improved. The as sessment of the disease progression is based on the measurement of the FEV1 (Forced Expiratory Volume in one second). OBJECTIVES: 1. To describe forced expiratory flows and volumes and com pare their interpretation according to different reference standards (Knudson, Gutiérrez, and multi ethnic GLI); 2. To describe bronchodilator response. Patients and Method: The medical records and spirometries of all patients with CF controlled at the Dr. Sotero del Rio Hospital were reviewed. Demographic background, sweat test results, genetic study , and bacteriological study were obtained. In addition, Forced Vital Capacity (FVC) was recorded as well as FEV1 and FEV1/FVC ratio. RESULTS: Data from 14 patients, were analyzed, seven males, aged 6-24 years, median 15 years, median BMI 18.15 (range 14.6-23.3), median sweat chloride test 76 mEq/l (range 50,2-119 mEq/l), seven patients with at least one F508del mutation. Using multi-ethnic and Gutierrez predictive formulas, lung function involvement occurred previously in relation to the use of Knudson equations. None of the patients had a significant bronchodilator response. CONCLUSION: The group of patients descri bed mostly presents functional respiratory involvement and had no bronchodilator response. The interpretation of functional respiratory involvement varies according to the theoretical values used.
Subject(s)
Humans , Male , Female , Child , Adolescent , Young Adult , Spirometry/standards , Bronchodilator Agents/therapeutic use , Cystic Fibrosis/diagnosis , Cystic Fibrosis/therapy , Reference Standards , Vital Capacity , Forced Expiratory Volume , Retrospective Studies , Follow-Up Studies , Treatment OutcomeABSTRACT
Desde el año 2007 existen guías internacionales para la realización e interpretación de espirometrías en preescolares. Un porcentaje de estos pacientes no logra obtener maniobras que cumplan con todos los criterios de aceptabilidad. El objetivo de este estudio fue desarrollar una escala de calidad mediante el juicio de expertos para interpretar estas espirometrías parcialmente aceptables. Material y Método: Se utilizó metodología Delphi, la cual permite llegar a un consenso entre expertos analizando un problema definido. Para esto se invitó a participar a pediatras especialistas en enfermedades respiratorias con dedicación en función pulmonar y que participan activamente en las sociedades científicas de la especialidad en Chile. Se realizaron rondas sucesivas solicitándoles su opinión por escrito acerca de los criterios utilizados para valorar espirometrías realizadas en preescolares. Estos criterios son los que definen la aceptabilidad de las maniobras espirométricas según las guías internacionales. Los grados de calidad propuestos fueron: muy bueno, bueno, regular y malo. Resultados: Participaron 13 de los 15 expertos invitados. En la primera ronda 9 de ellos estuvieron en desacuerdo con el grado de calidad regular. En la segunda ronda esta se eliminó y respondieron 11 expertos; 9 de ellos estuvieron de acuerdo con la utilización de esta nueva versión. El criterio más discutido fue el final de la espiración. Conclusión: La mayoría de los expertos estuvieron de acuerdo con la escala final, usando las apreciaciones muy bueno, bueno y malo. Esta contribuiría a mejorar el rendimiento de las espirometrías realizadas en niños entre 2 y 5 años.
Since 2007, there are international guidelines for implementation and interpretation of spirometry in preschool children. A percentage of these patients cannot obtain maneuvers that meet all eligibility criteria. The objective of this study was to develop a quality scale for interpreting these partially acceptable spirometry. Material and Method: Delphi methodology was used, which allows to reach consensus among experts analyzing a defined problem. We invited to participate pediatric pneumologists dedicated to lung function and who participated actively in scientific specialty societies in Chile. Successive rounds were conducted with questionnaires about criteria used to assess spirometry in preschool children. These criteria define the acceptability of spirometric maneuvers according to international guidelines. Proposed quality grades were very good, good, fair and bad. Results: Thirteen of the 15 invited experts accepted our invitation. In the first round 9 disagreed with the degree of regular quality. In the second round this was removed and 11 experts answered, 9 of them agreed with the use of this new version. The most contentious criterion was the end of expiration. Conclusion: Most experts agreed with the final scale, using very good, good and bad judgments. This would help to improve the performance of spirometry in children between 2 and 5 years.
Subject(s)
Humans , Male , Female , Child, Preschool , Adult , Middle Aged , Aged , Respiratory Function Tests , Spirometry/methods , Practice Guidelines as Topic , Spirometry/standards , Chile , Prospective Studies , Surveys and Questionnaires , Delphi Technique , InternationalityABSTRACT
ABSTRACT Objective: To determine the cut-off points for FEV1, FEV0.75, FEV0.5, and FEF25-75% bronchodilator responses in healthy preschool children and to generate reference values for FEV0.75. Methods: This was a cross-sectional community-based study involving children 3-5 years of age. Healthy preschool children were selected by a standardized questionnaire. Spirometry was performed before and after bronchodilator use. The cut-off point of the response was defined as the 95th percentile of the change in each parameter. Results: We recruited 266 children, 160 (60%) of whom were able to perform acceptable, reproducible expiratory maneuvers before and after bronchodilator use. The mean age and height were 57.78 ± 7.86 months and 106.56 ± 6.43 cm, respectively. The success rate for FEV0.5 was 35%, 68%, and 70% in the 3-, 4-, and 5-year-olds, respectively. The 95th percentile of the change in the percentage of the predicted value in response to bronchodilator use was 11.6%, 16.0%, 8.5%, and 35.5% for FEV1, FEV0.75, FEV0.5, and FEF25-75%, respectively. Conclusions: Our results provide cut-off points for bronchodilator responsiveness for FEV1, FEV0.75, FEV0.5, and FEF25-75% in healthy preschool children. In addition, we proposed gender-specific reference equations for FEV0.75. Our findings could improve the physiological assessment of respiratory function in preschool children.
RESUMO Objetivo: Determinar os pontos de corte de resposta ao broncodilatador do VEF1, VEF0,75, VEF0,5 e FEF25-75% em crianças pré-escolares saudáveis e gerar valores de referência para o VEF0,75. Métodos: Foi realizado um estudo transversal de base comunitária em crianças de 3-5 anos de idade. Pré-escolares saudáveis foram selecionados por um questionário padronizado. Foi realizada espirometria antes e depois do uso de broncodilatador. Foram definidos os pontos de corte dessa resposta como o percentil 95 de variação em cada parâmetro. Resultados: Foram recrutadas 266 crianças, e 160 (60,0%) foram capazes de gerar manobras expiratórias aceitáveis e reprodutíveis antes e depois do uso de broncodilatador. As médias de idade e estatura dos participantes foram 57,78 ± 7,86 meses e 106,56 ± 6,43 cm, respectivamente. A taxa de sucesso para o VEF0,5 foi de 35%, 68% e 70%, respectivamente, nos participantes com 3, 4 e 5 anos de idade. O percentil 95 de variação percentual do valor previsto na resposta ao broncodilatador foram, respectivamente, de 11,6%, 16,0%, 8,5% e 35,5%, para VEF1, VEF0,75, VEF0,5 e FEF25-75%. Conclusões: Nossos resultados definiram pontos de corte de resposta ao broncodilatador para o VEF1, VEF0,75, VEF0,5 e FEF25-75 em crianças pré-escolares saudáveis. Adicionalmente, foram propostas equações de referência para o VEF0,75, separadas por sexo. Os achados deste estudo podem melhorar a avaliação fisiológica da função respiratória em pré-escolares.
Subject(s)
Humans , Male , Female , Child, Preschool , Bronchodilator Agents/therapeutic use , Spirometry/standards , Cross-Sectional Studies , Forced Expiratory Flow Rates , Forced Expiratory Volume , Reference Values , Reproducibility of Results , Surveys and QuestionnairesABSTRACT
Background. Most of the Indian studies on prediction equations for spirometry in adults are several decades old and may have lost their utility as these were carried out with equipment and standardisation protocols that have since changed. Their validity is further questionable as the lung health of the population is likely to have changed over time. Objective. To develop prediction equations for spirometry in adults of north Indian origin using the 2005 American Thoracic Society/European Respiratory Society (ATS/ERS) recommendations on standardisation. Methods. Normal healthy non-smoker subjects, both males and females, aged 18 years and above underwent spirometry using a non-heated Fleisch Pneumotach spirometer calibrated daily. The dataset was randomly divided into training (70%) and test (30%) sets and the former was used to develop the equations. These were validated on the test data set. Prediction equations were developed separately for males and females for forced vital capacity (FVC), forced expiratory volume in first second (FEV1), FEV1/FVC ratio, and instantaneous expiratory flow rates using multiple linear regression procedure with different transformations of dependent and/or independent variables to achieve the best-fitting models for the data. The equations were compared with the previous ones developed in the same population in the 1960s. Results. In all, 685 (489 males, 196 females) subjects performed spirometry that was technically acceptable and repeatable. All the spirometry parameters were significantly higher among males except the FEV1/FVC ratio that was significantly higher in females. Overall, age had a negative relationship with the spirometry parameters while height was positively correlated with each, except for the FEV1/FVC ratio that was related only to age. Weight was included in the models for FVC, forced expiratory flow (FEF75) and FEV1/FVC ratio in males, but its contribution was very small. Standard errors of estimate were provided to enable calculation of the lower limits of normal and standardised residuals for these parameters. The equations were found to be valid on the test dataset, and therefore, may be extended to general population. Comparison with the 1960s equations revealed lack of good agreement, and substantially higher predicted FVC with the current equations, especially in the forty-years-plus age group, in both males and females. Even in the age group upto 40 years, the level of agreement was clinically not acceptable. Conclusions. Validated prediction equations have been developed for spirometry variables in adults of north Indian origin using the current ATS/ERS spirometry standardisation recommendations. The equations suggest an improvement in the lung health of the population over time in the middle-aged and the elderly. These equations should address a long-felt unmet need and enable a more appropriate evaluation of spirometry data in different chest diseases in Indian subjects.
Subject(s)
Adult , Age Factors , Female , Humans , India , Male , Middle Aged , Reference Values , Reproducibility of Results , Respiratory Physiological Phenomena , Sex Factors , Spirometry/methods , Spirometry/standardsABSTRACT
Spirometry must meet international standardizations criteria to be valid. Those criterias are classically described to be applied on starting from 6 years old children. In recent years, there have been numerous publications demonstrating that spirometry can be performed in preschool children, whenever the standardization is adapted to this age group. In this revision we describe the differences to perform and interpret spirometry between preschool children and children over 6 years old.
Para que la espirometría sea válida, debe cumplir con los criterios establecidos en estandarizaciones internacionales, las que clásicamente están descriptas para ser aplicadas a partir de los 6 años. En los últimos años, han surgido numerosas publicaciones que demuestran que la espirometría puede ser realizada en preescolares, siempre que se adapten las exigencias a este grupo etario. Se describen las diferencias entre el niño preescolar y el niño mayor de 6 años, para realizar e interpretar la espirometría.
Subject(s)
Humans , Child, Preschool , Child , Spirometry/standards , Reference StandardsABSTRACT
The purpose of this study was to compare the Korean COPD guideline to GOLD consensus report in terms of acute exacerbation. A total of 361 patients were enrolled in this study, and 16.9% of them experienced acute exacerbation during the follow-up. A total of 6.3% of patients in GOLD A, 9.5% in GOLD B, 7.7% in GOLD C and 17.0% of GOLD D experienced exacerbation during the first year of follow-up, respectively (P=0.09). There was no one who experienced exacerbation during the first year of follow-up in the Korean group 'ga'. The 12-month exacerbation rates of Korean group 'na' and 'da' were 4.5% and 16.0%, respectively (P<0.001). We explore the experience of exacerbation in patients with change of their risk group after applying Korean COPD guideline. A total of 16.0% of the patients who were reclassified from GOLD A to Korean group 'da' experienced acute exacerbation,and 15.3% from GOLD B to Korean group 'da' experienced acute exacerbation. In summary, the Korean COPD guideline is useful to differentiate the high risk from low risk for exacerbation in terms of spirometry. This indicates that application of Korean COPD guideline is appropriate to treat Korean COPD patients.
Subject(s)
Aged , Female , Humans , Male , Acute Disease , Disease Progression , Practice Guidelines as Topic , Pulmonary Disease, Chronic Obstructive/classification , Pulmonary Medicine/standards , Reproducibility of Results , Republic of Korea , Sensitivity and Specificity , Severity of Illness Index , Spirometry/standardsABSTRACT
OBJETIVOS: Valores de referência para testes de função pulmonar diferem em amostras de diferentes países, incluindo valores para pré-escolares. O objetivo principal do presente estudo foi derivar valores de referência em nossa população. MÉTODOS: Foi realizado estudo prospectivo, com aplicação de questionário a 425 crianças pré-escolares com idade variando entre três e seis anos, provenientes de escolas e creches públicas e privadas de uma cidade metropolitana do Brasil. As crianças foram selecionadas por amostragem aleatória simples dos referidos educandários. Foram avaliados: PFE, CVF, VEF1 VEF0,50, FEF25-75 e as relações: VEF1/CVF, VEF0,5/CVF e FEF25-75/CVF. RESULTADOS: Das 425 crianças recrutadas, 321 (75,6%) realizaram os testes. Destas, 135 (42,0%) apresentaram manobras aceitáveis, com curvas expiratórias completas e fizeram parte da análise de regressão para definir os valores de referência. Por análise de regressão linear e logarítmica, a estatura e o sexo influenciaram significativamente nas medidas de CVF. No sexo masculino, o r² se elevou com o modelo logarítmico, para a CVF e VEF1, porém o modelo linear foi mantido, por sua simplicidade. Os limites inferiores foram calculados através das medidas do 5º percentil dos resíduos. CONCLUSÃO: Curvas expiratórias completas são de mais difícil obtenção em pré-escolares. Além da estatura, o sexo também influencia nas medidas de CVF e VEF1. Foram definidos valores de referência para espirometria em crianças pré-escolares, nessa população, aplicáveis a populações semelhantes.
OBJECTIVES: Reference values for lung function tests differ in samples from different countries, including values for preschoolers. The main objective of this study was to derive reference values in this population. METHODS: A prospective study was conducted through a questionnaire applied to 425 preschool children aged 3 to 6 years, from schools and day-care centers in a metropolitan city in Brazil. Children were selected by simple random sampling from the aforementioned schools. Peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory volumes (FEV1, FEV0.50), forced expiratory flow (FEF25-75) and FEV1/FVC, FEV0.5/FVC and FEF25-75/FVC ratios were evaluated. RESULTS: Of the 425 children enrolled, 321 (75.6%) underwent the tests. Of these, 135 (42.0%) showed acceptable results with full expiratory curves and thus were included in the regression analysis to define the reference values. Height and gender significantly influenced FVC values through linear and logarithmic regression analysis. In males, R2 increased with the logarithmic model for FVC and FEV1, but the linear model was retained for its simplicity. The lower limits were calculated by measuring the fifth percentile residues. CONCLUSION: Full expiratory curves are more difficult to obtain in preschoolers. In addition to height, gender also influences the measures of FVC and FEV1. Reference values were defined for spirometry in preschool children in this population, which are applicable to similar populations.
Subject(s)
Child, Preschool , Female , Humans , Male , Lung/physiology , Spirometry/standards , Body Height , Brazil , Prospective Studies , Reference Values , Sample Size , Sex Factors , Surveys and QuestionnairesABSTRACT
The objective of this study was to develop new spirometric reference equations for the Korean population using the raw data of the fourth Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009). A total of 4,753 healthy lifelong nonsmokers without respiratory diseases and symptoms were selected as the reference population. Spirometric reference equations were derived through multiple regression analysis. The newly developed reference equations for spirometry parameters were as follows: FEV1 (L) = -0.00025410 x (Age [years])2 + 0.00012644 x (Height [cm])2 - 0.00262 x Weight (kg) + 0.61493 (Men); FEV1 (L) = -0.00017538 x Age2 + 0.00009598 x Height2 - 0.00231 x Weight + 0.46877 (Women); FVC (L) = -0.00000219 x Age3 + 0.0000006995642 x Height3 + 1.19135 (Men); FVC (L) = 0.0167 x Age - 0.00030284 x Age2 + 0.0000005850287 x Height3 + 0.77609 (Women); FEV1/FVC (%) = -0.00289 x Age2 - 0.16158 x Height3 + 114.13736 (Men); FEV1/FVC (%) = -0.21382 x Age - 0.00000143 x Height3 + 97.62514 (Women). The newly developed spirometric reference equation in this study can be used as criteria for the interpretation of spirometry results and the diagnosis of respiratory diseases in Korean adults.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Algorithms , Asian People , Forced Expiratory Volume/physiology , Nutrition Surveys , Reference Values , Regression Analysis , Republic of Korea , Spirometry/standardsABSTRACT
Introducción: se desconocen las características de los laboratorios de función pulmonar (LFP) del país. Estos datos pueden aportar elementos para el desarrollo de normativas que regulen su funcionamiento. Métodos: se estudiaron 35 LFP, agrupados en A) Área Metropolitana, y B) Interior del país, mediante entrevistas y formularios electrónicos, respectivamente. Se recabaron datos referidos a estructura y procesos. Resultados: se observó falta de uniformidad de diversa índole y magnitud en diversos aspectos. Estas diferencias fueron más evidentes bajo el análisis individual de los LFP que cuando se analizaron en conjunto según área geográfica y tipo de gestión. El 94% refiere basar su práctica en guías ATS/ERS, y la amplia mayoría de los responsables de los LFP están de acuerdo en implementar un programa de control de calidad. Discusión: la falta de uniformidad entre los LFP puede responder a múltiples causas: a) ausencia de normativas, b) LFP en espacios no diseñados para ese propósito, c) falta de programas de capacitación, d) costo de insumos y accesorios, e) ausencia de políticasnacionales de acceso al recurso.Conclusión: es necesaria la unificación de criterios en forma consensuada entre los participantes y las autoridades sanitarias, respecto de estructura y procesos. Se espera con esto garantizar un acceso uniforme y de alta calidad para pacientes, médicos y financiadores.
Introduction: The characteristics of pulmonary function laboratories (PFL) in our country are unknown. This information is essential to develop policies intended to harmonize theirfunctioning. Methods: Thirty-five PFL where surveyed in A) Buenos Aires Metropolitan Area, and B) Countryside, through interviews and electronic forms, respectively. Data on structure andprocesses were requested. Results: Lack of uniformity of different nature and magnitude in several aspects was observed. These differences were more apparent in the individual analysis than in the cluster analysis by geographic area and type of management of the PFL. Ninety-four percent of the PFL follow in their practice the ATS/ERS guidelines. The vast majority of their directors agree on implementing a quality control program. Discussion: The lack of uniformity among the PFL can be due to multiple causes: a) absenceof regulations, b) PFL located at inadequate premises, c) lack of training programs, d) cost of supplies and accessories, e) absence of national policies for access to their services.Conclusion: It is necessary to achieve agreement upon criteria among the participants and health authorities in respect of structure and processes. It is expected to ensure fast and high quality access to patients, physicians and health supporters.
Subject(s)
Humans , Spirometry/instrumentation , Spirometry/standards , Accreditation , Argentina , Data Collection , Workforce , Quality ControlABSTRACT
Introducción: La estenosis traqueal (ET) es una complicación de la intubación traqueal o de la traqueostomía. La dilatación con endoscopía rígida (DER) es el tratamiento inicial en presencia de ET sintomática. Habitualmente estos pacientes presentan hallazgosespirométricos sugestivos de ET: aplanamiento en las ramas inspiratoria, espiratoria o ambas de la curva flujo-volumen (CFV). Asimismo, índices numéricos correlacionan valores espirométricos y sustentan el diagnóstico presuntivo de ET. Objetivos: Evaluar las características espirométricas de los pacientes con ET post intubación, previo y posterior a la DER. Materiales y métodos: Se analizaron todas las DER realizadasen pacientes con ET entre Noviembre de 2006 y Marzo de 2009. Todos los pacientes incluidos contaban con espirometría previa y posterior a la DER. Se analizó el volumen espiratorio forzado en 1° segundo (VEF1), pico flujo espiratorio (PFE), índice VEF1/PFEy la morfología de la CFV. Resultados: Veinticinco dilataciones traqueales fueron realizadas en 15 pacientes con ET. Posterior a la DER se observó un incremento en el VEF1 y PEF (total y %), así como una disminución en el índice VEF1/PEF. La CFV mostró un mayor área bajo la curva como consecuencia de menor aplanamiento de una o ambas ramas. Conclusiones: La espirometria pre-dilatación confirmó el diagnóstico de ET utilizando el VEF1, PEF y su índice (análisis numérico). La morfología de la CFV sustentó dicho diagnostico (análisis visual). La espirometría post-dilatación permitióobjetivar la mejoría de la ET a través de ambos tipos de parámetros, coincidiendo con el aumento del diámetro traqueal observado endoscópicamente.
Introduction: Tracheal stenosis (TS) is a complication of endotracheal intubation or tracheostomy. Rigid endoscopic dilatation (RED) is the initial treatment in symptomatic TS. Usually these patients have spirometric results that suggest such alteration: flatteningof the flow-volume curve (FVC), either in the espiratory, the inspiratory or bothcurves. Also, quantitative indexes among different spirometric values are correlated suggesting the presence of TS. Objectives: To assess spirometric characteristics in patients who suffer from symptomatic TS due to airway intubation, before and after therapeutic RED. Materials and methods: All RED procedures in patients with symptomatic TS performed between November 2006 and March 2009 were included in the analysis. All included patients should have a spirometry performed before andafter tracheal dilatation. Forced expiratory volume in 1st second (FEV1), peak expiratory flow rate (PEFR), FEV1/PEFR index and FVC morphology were taken into consideration. Results: Twenty five ED were performed in 15 patients with TS. An increase in FEV1(total and %) and PEFR (total and %) and a decrease in FEV1/PEFR index were observed in the post-dilatation values. The FVC showed an improvement in its morphology through a larger area under the curve because of less flattening in one or both curves.Conclusions: Pre-dilatation spirometry confirmed TS diagnosis using FEV1, PEFR and its index (quantitative analysis) and by the morphology of the FVC (visual analysis). Post-dilatation spirometry allowed the documentation of TS improvement through both kinds of parameters, in agreement with the improvement of the luminal diameter seen endoscopically.
Subject(s)
Humans , Male , Adolescent , Female , Young Adult , Spirometry/instrumentation , Spirometry/standards , Tracheal Stenosis/complications , Argentina , Dilatation , Endoscopy , TracheostomyABSTRACT
OBJETIVO:Um dos maiores problemas no uso da espirometria é a avaliação dos valores obtidos em comparação a valores de referência padronizados. Tais valores de referência devem ser determinados pelo estudo de populações semelhantes àquelas que se deseja utilizar. Considerando as diferenças antropométricas entre raças e o efeito de variáveis regionais, como clima e qualidade do ar, recomenda-se que esses padrões sejam definidos e utilizados regionalmente. O objetivo deste estudo foi medir os valores espirométricos em residentes da província de Mazandaran, no Irã; determinar quais valores de referência padronizados se correlacionam de forma mais próxima aos valores obtidos; e produzir equações preditivas para a população alvo. MÉTODOS: Estudo transversal com 1.499 voluntários, dos quais dados demográficos e antropométricos foram coletados. Após terem sido instruídos quanto ao procedimento adequado, cada voluntário foi submetido à espirometria, sendo obtidas três curvas espirométricas de acordo com os critérios de aceitabilidade da American Thoracic Society. O teste com os maiores valores de VEF1 e CVF foram utilizados na análise. RESULTADOS: Houve correlações significativas entre os valores medidos e os valores de referência em ambos os gêneros. As correlações mais fortes ocorreram com os valores de referência da European Respiratory Society e com a faixa etária de 18-20 anos. As equações preditivas produzidas basearam-se nos coeficientes de regressão obtidos e nos dados demográficos coletados. CONCLUSÕES: Nossos resultados mostram que os valores de referência da European Respiratory Society são os mais apropriados para a população estudada.
OBJECTIVE: One of the major issues in the use of spirometry is the evaluation of the values obtained in comparison with standardized reference values. Such reference values should be determined by studying populations similar to the population in which they are intended to be used. Considering the anthropometric differences among races and the effect of regional issues, such as climate and air quality, it is recommended that these standards be set and used regionally. The objective of this study was to measure the spirometric values in residents of the Mazandaran province in Iran, as well as to determine which standardized reference values most closely correlate with the values obtained and to devise predictive equations for the target population. METHODS: This was a cross-sectional study of 1,499 volunteers, from whom demographic and anthropometric data were collected. After having been instructed in the correct procedure, each volunteer underwent spirometry. From each volunteer, we obtained three spirometry curves that met the acceptability criteria established by the American Thoracic Society. The test with the highest values of FEV1 and FVC was employed in the analysis. RESULTS: We observed significant correlations between the measured values and the reference values, for both genders. The strongest correlations were with the European Respiratory Society reference values and with the 18-20 year age bracket. The predictive equations devised were based on the regression coefficients obtained and the demographic data collected. CONCLUSIONS: Our results show that the European Respiratory Society standard is the most appropriate standard for use in the population studied.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Young Adult , Spirometry/standards , Anthropometry , Epidemiologic Methods , Iran/ethnology , Reference ValuesABSTRACT
In China there are 1,923,842 Korean Chinese, who live mostly (92.27%) in the country's three northeast provinces. In spite of this sizeable number, no spirometric data are available at present on them. The present study investigated normal spirometric reference values for the Korean Chinese children and adolescents. Spirometry was performed in 443 healthy Korean Chinese children and adolescents aged 8-18 yr with measurements of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF) and maximum mid-expiratory flow (MMEF). Reference equations for FEV1, FVC, PEF and MMEF were derived by using multiple regression analysis. All of the measured spirometric parameters correlated positively with height and age significantly (P < 0.001). The predicted values of FVC and FEV1 were higher than values obtained by using Caucasian and other Asian equations (P < 0.001). A set of spirometric reference equations has been derived using a relatively large, healthy, non-smoking young Korean Chinese population with a wide range of ages and heights, the results of which differ from those gained from several other reference equations. These reference equations should be used for evaluation of lung function in this population.
Subject(s)
Adolescent , Child , Female , Humans , Male , China , Forced Expiratory Volume , Lung/physiology , Maximal Expiratory Flow Rate , Peak Expiratory Flow Rate , Reference Values , Republic of Korea/ethnology , Spirometry/standards , Vital CapacityABSTRACT
OBJETIVO: Utilizar os dados clínicos e espirométricos para distinguir entre os padrões restritivo e inespecífico dos resultados dos testes de função pulmonar em pacientes com CVF reduzida e relação VEF1/CVF normal ou elevada. MÉTODOS: Foram avaliados resultados de testes de função pulmonar de 211 pacientes adultos submetidos à espirometria e a medidas de volumes pulmonares. O diagnóstico clínico na solicitação do exame e diversos dados funcionais foram utilizados para diferenciar pacientes com o padrão restritivo "verdadeiro" (CPT reduzida) daqueles com o padrão inespecífico (CPT normal). RESULTADOS: Na amostra estudada, a CPT estava reduzida em 144 casos e estava dentro da faixa normal em 67. As causas mais comuns do padrão inespecífico foram doenças pulmonares obstrutivas, insuficiência cardíaca congestiva, obesidade, bronquiolite, doenças intersticiais e doenças neuromusculares. Em pacientes com hipótese diagnóstica de fibrose pulmonar, doenças pleurais ou doenças da parede torácica, o valor preditivo positivo (VPP) para restrição foi > 90 por cento. Em homens, a CVF < 60 por cento do previsto teve um VPP para restrição de 98,8 por cento. Em mulheres, o padrão restritivo foi encontrado em 84,4 por cento daquelas com CVF < 50 por cento do previsto. Uma diferença entre VEF1 por cento e CVF por cento > 0 por cento teve um VPP para restrição de 89,5 por cento. Após regressão logística, uma escala de pontos foi desenvolvida para predizer o padrão restritivo. CONCLUSÕES: O padrão restritivo pode ser identificado com segurança em diversos casos com VEF1 e CVF reduzidos e relação VEF1/CVF normal usando-se um algoritmo que leva em conta o diagnóstico clínico e alguns achados espirométricos.
OBJECTIVE: To use clinical and spirometry findings in order to distinguish between the restrictive and nonspecific patterns of pulmonary function test results in patients with low FVC and a normal or elevated FEV1/FVC ratio. METHODS: We analyzed the pulmonary function test results of 211 adult patients submitted to spirometry and lung volume measurements. We used the clinical diagnosis at the time spirometry was ordered, together with various functional data, in order to distinguish between patients presenting with a "true" restrictive pattern (reduced TLC) and those presenting with a nonspecific pattern (normal TLC). RESULTS: In the study sample, TLC was reduced in 144 cases and was within the normal range in 67. The most common causes of a nonspecific pattern were obstructive disorders, congestive heart failure, obesity, bronchiolitis, interstitial diseases, and neuromuscular disorders. In patients given a working diagnosis of pulmonary fibrosis, pleural disease, or chest wall disease, the positive predictive value (PPV) for restriction was > 90 percent. In males, an FVC < 60 percent of predicted had a PPV for restriction of 98.8 percent. In females, the restrictive pattern was found in 84.4 percent of those with an FVC < 50 percent of predicted. A difference of > 0 percent between the FEV1 percent and the FVC percent had a PPV for restriction of 89.5 percent. After performing logistic regression, we developed a point scale for predicting the restrictive pattern. CONCLUSIONS: In many patients with reduced FEV1, reduced FVC, and a normal FEV1/FVC ratio, the restrictive pattern can be identified with confidence through the use of an algorithm that takes the clinical diagnosis and certain spirometry measurements into account.