Reference values for spirometry in Brazilian children.

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.

Bronchodilator response cut-off points and FEV 0.75 reference values for spirometry in preschoolers.

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.

Exhaled nitric oxide as a diagnostic tool for wheezing in preschool children: A diagnostic accuracy study.

Background: Airways inflammation may precede pulmonary dysfunction in wheezing individuals. The fraction of exhaled nitric oxide (FENO) has been described as a useful method for wheezing diagnosis in children, however, its application requires evidence. This study aimed to determine the accuracy of FENO in identifying wheezing in preschoolers.

Reference values for spirometry in preschool children.

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.

Early termination of exhalation: effect on spirometric parameters in healthy preschool children.

Objective: To evaluate the acceptability and reproducibility of spirometry in preschool children; to estimate the effect size of early termination of exhalation (ETE) on FVC, FEV(1) and FEV(0.5); and to evaluate the validity of FEV(0.5) in curves with ETE.

[Asthma in schoolchildren from Recife, Brazil. Prevalence comparison: 1994-95 and 2002].

Objectives: To describe the prevalence of asthma and asthma variants in schoolchildren from Recife in 2002, and to compare these data with data from 1994-95; to analyze the relationship between maternal schooling and the presence of asthma or worsening asthma; and to evaluate the diagnostic accuracy of the yearly prevalence of wheezing as an asthma indicator.

Methods: Cross-sectional study. A probabilistic sample of 3,086 and 2,774 13- and 14-year-old students answered a written questionnaire in 1994-95 and 2002, as part of the International Study of Asthma and Allergies in Childhood.