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Reference values for spirometry in Brazilian children
Marcus Herbert Jones1, Paula Cristina Vasconcellos Vidal1, Fernanda Cordoba Lanza2
1. Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS - Porto Alegre (RS) Brasil.
Insights
New spirometry reference values for Brazilian children aged 3-12 were created, showing current equations underestimate lung function, especially in darker-skinned children. These updated equations are recommended for accurate pediatric lung health assessments.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
- Public Health Research
Background:
- Spirometry is crucial for assessing lung function in children.
- Existing reference equations in Brazil may not accurately reflect the diverse pediatric population.
- Accurate reference values are needed for diagnosing and managing pediatric respiratory conditions.
Purpose of the Study:
- To establish new, updated reference values for spirometry in Brazilian children aged 3 to 12 years.
- To compare these new values with existing spirometry equations used in Brazil.
- To investigate the influence of skin color on spirometric reference values.
Main Methods:
- A cross-sectional study combining primary and secondary data from 1,990 healthy Brazilian children (3-12 years).
- Quantile regression analysis was used to generate new reference equations after log-transforming spirometric and anthropometric data.
- Spirometric parameters including FEV1, FVC, FEV1/FVC, and FEF25-75% were analyzed, considering self-reported skin color.
Main Results:
- New spirometric reference equations were generated for white, black, and brown-skinned children.
- Height and age were significant predictors of FEV1 and FVC, with skin color also playing a role.
- The newly derived reference values were significantly higher than those from current Brazilian equations, particularly for children with black or brown skin.
Conclusions:
- Novel spirometric reference equations have been developed for Brazilian children aged 3-12, categorized by skin color.
- Current spirometry equations used in Brazil appear to underestimate lung function in this pediatric age group.
- The proposed equations are recommended for more accurate assessment of lung function 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. 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.
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