Reference Values for Spirometry Derived Using Lambda, Mu, Sigma (LMS) Method in Korean Adults: in Comparison with Previous References

BACKGROUND: The present study aimed to update the prediction equations for spirometry and their lower limits of normal (LLN) by using the lambda, mu, sigma (LMS) method and to compare the outcomes with the values of previous spirometric reference equations. METHODS: Spirometric data of 10,249 healthy non-smokers (8,776 females) were extracted from the fourth and fifth versions of the Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007–2009; V, 2010–2012). Reference equations were derived using the LMS method which allows modeling skewness (lambda [L]), mean (mu [M]), and coefficient of variation (sigma [S]). The outcome equations were compared with previous reference values. RESULTS: Prediction equations were presented in the following form: predicted value = e {a + b × ln(height) + c × ln(age) + M − spline}. The new predicted values for spirometry and their LLN derived using the LMS method were shown to more accurately reflect transitions in pulmonary function in young adults than previous prediction equations derived using conventional regression analysis in 2013. There were partial discrepancies between the new reference values and the reference values from the Global Lung Function Initiative in 2012. CONCLUSION: The results should be interpreted with caution for young adults and elderly males, particularly in terms of the LLN for forced expiratory volume in one second/forced vital capacity in elderly males. Serial spirometry follow-up, together with correlations with other clinical findings, should be emphasized in evaluating the pulmonary function of individuals. Future studies are needed to improve the accuracy of reference data and to develop continuous reference values for spirometry across all ages.

Percentages of the measured value vs.the expected value of pulmonary function parameters in healthy children aged 5-14 years in Beijing / 中华实用儿科临床杂志

Objective To investigate the distribution of measured value and the expected value of spirometry parameters in healthy children aged 5-14 years old in Beijing,and to provide evidence for clinical interpretation precisely.Methods Four hundred healthy children (198 boys and 202 girls) aged 5 to 14 years from the kindergartens and the primary schools in Beijing were selected as subjects.All of the parameters were measured by using Jaeger Masterscreen spirometry machine(Germany).Pulmonary function parameters including forced vital capacity(FVC),forced expiatory volume in 1 second (FEV1),FEV1/FVC,peak expiratory flow(PEF),forced expiratory flow at 50% of vital capacity(FEF50),forced expiratory flow at 75% of vital capacity(FEF75),and the maximal midexpiratory flow(MMEF) were collected for analysis.The expected values of the 7 parameters above were calculated according to Zapletal prediction equations(4-18 years old).The measured value vs.the expected value was calculated.Results Children aged 5 to 12 years had similar height and weight between boys and girls,and the differences were not significant(all P>0.05);while boys were taller and heavier than girls in 13-<14 years old group and 14 years old group,and the diffe-rences were significant(t=3.35,2.05,5.99,2.67;all P<0.05).The mean measured value vs.the expected value of PEF,FVC,FEV1,FEV1/FVC of children in different gender and age groups ranged between 105.0%-114.7%,95.4%-106.8%,104.6%-115.4% and 105.8%-112.6%,respectively.The mean measured value vs.the expected value of small airway function parameters FEF50,FEF75,MMEF was as follows respectively:79.7%-103.7%,70.2%-110.5%,and 81.6%-114.7%.The low limit of normal(LLN) measured value vs.the expected value of the 7 pulmonary function parameters was as follows:PEF 85.0%,FVC 84.7%,FEV1 92.4%,FEV1/FVC 98.4%,FEF50 67.7%,FEF75 60.1%,and MMEF 71.0%.Conclusions The pulmonary function parameters of the healthy children in Beijing are higher than those of the Zapletal prediction.The measured value vs.the expected value of FEV1 92.4%,FEV1/FVC 98.4%,PEF 85.0%,FVC 84.7%,FEF50 67.7%,FEF75 60.1%,and MMEF 71.0% can be used as LLN in 5-14 years old children.

Comparación entre los criterios de la global initiative for chronic obstructive lung disease y el límite inferior de la normalidad para el diagnóstico de enfermedad pulmonar obstructiva crónica / Comparison between global initiative for chronic obstructive lung disease criterion and lower limit of normal criterion for the diagnosis of chronic obstructive pulmonary disease

Introducción: existe evidencia de limitaciones que presentan los métodos utilizados para interpretar la función pulmonar como obstructiva. Objetivo: analizar las ventajas y las desventajas del método recomendado por la Global Initiative for Chronic Obstructive Lung Disease (GOLD) y las del límite inferior de la normalidad (LIN). Métodos: se realizó un estudio de evaluación de estas tecnologías biomédicas. Se incluyeron 732 pacientes con criterio clínico de EPOC con disnea (grupo 1) y 2 grupos controles constituidos por 100 individuos sanos de 18 a 30 años (grupo 2) y otro de 100 individuos sanos de 60 años o más (grupo 3). A todos los grupos se les aplicó ambos métodos de interpretación espirométrica y se compararon los resultados. Resultados: fueron negativos por los criterios de la GOLD 26 pacientes (3,5 por ciento) y por el LIN, 79 (10,8 por ciento). El método de la GOLD reflejó 4 por ciento de casos con función pulmonar obstructiva en el grupo 3 y el LIN evidenció 25 por ciento de negativas en el grupo 2. Cuando se aplicaron los dos métodos combinados el 100 por ciento de los pacientes con EPOC clínica fueron positivos de obstrucción bronquial. Conclusiones: el método de la GOLD es más exacto que el LIN para el diagnóstico de EPOC. Sin embargo, el LIN es más efectivo en hombres mayores de 60 años. Al utilizar ambos métodos a la vez se evidencia que se logra el diagnóstico de EPOC en el 100 por ciento de los casos(AU)

Introduction: there is evidence of the limitations of the methods used to interpret pulmonary function such as obstructive. Objective: compare the advantages and disadvantages of the method recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the lower limit of normal (LLN). Methods: an evaluation study of these biomedical technologies was conducted. 732 patients were included with clinical criteria of chronic obstructive pulmonary disease (COPD) with dyspnea (group 1) and 2 control groups of 100 healthy individuals of 18-30 years (group 2) and another 100 healthy individuals aged 60 or more (group 3). All groups were applied both spirometric interpretation methods and the results compared. Results: 26 patients (3.5 percent) were negative according to GOLD criteria and 79 (10.8 percent) according to LIN. The GOLD method reflected 4 percent of cases with obstructive lung function in group 3 and LIN showed 25 percent negative in group 2. When the two combined methods were applied to 100 percent of COPD patients were positive for clinic bronchial obstruction. Conclusions: GOLD method is more accurate than LIN for the diagnosis of COPD. However, LIN is most effective in men older 60 years. By using both methods at a time, COPD diagnosis is achieved in 100 percent of cases(AU)

Comparison of the Prevalence of Chronic Obstructive Pulmonary Disease Diagnosed by Lower Limit of Normal and Fixed Ratio Criteria

The Global Initiative of Chronic Obstructive Lung Disease (GOLD) guidelines define chronic obstructive pulmonary disease (COPD) in subjects with FEV1/FVC or =65, 14.9% and 31.1%, respectively. In conclusion, the prevalence of COPD by LLN criterion was significantly lower in elderly compared to fixed ratio of FEV1/FVC. Implementing LLN criterion instead of fixed ratio of FEV1/FVC may reduce the risk of over-diagnosis of COPD in elderly people.