Measuring interrupter resistance (Rint) is an increasingly popular lung function technique and especially suitable for preschool children because it is simple, quick and requires only passive cooperation. A European Respiratory Society (ERS)/American Thoracic Society (ATS) Task Force recently published empirical recommendations related to procedures, limitations and interpretation of the technique. However, for valid interpretation, high-quality reference equations are required and these have been lacking. The aim of the present study was to collate Rint data from healthy children in order to produce more robust reference equations. A further aim was to examine the influence of methodological differences on predicted Rint values.Rint data from healthy children were collected from published and unpublished sources. Reference equations for expiratory and inspiratory Rint were developed using the LMS (lambda, mu, sigma) method.Data from 1,090 children (51% males) aged 3-13 yrs were collated to construct sex-specific reference equations for expiratory Rint and data from 629 children (51% males) were collated for inspiratory Rint. Height was the best independent predictor of both expiratory and inspiratory Rint. Differences between centres were clinically irrelevant, and differences between ethnic groups could not be examined.The availability of a large and generalisable sample and the use of modern statistical techniques enabled the development of more appropriate reference equations for Rint in young children.

Spirometric reference equations that use only height for predicting pulmonary function are unsuitable for describing the progression of pulmonary function. Those that incorporate height and age demonstrate some discrepancy with longitudinal data. Failure to take these spurious trends into account leads to significant errors in estimating the natural course of respiratory disease, in allocating patients to treatment groups, or in assessing long-term effects of drug intervention in school children and adolescents.

No abstract

No abstract

This study was conducted to describe the relationship between anthropometric parameters and lung function in Estonian children, to determine the reference values for spirometry, and to compare these results with other data sets. The results are based on 1170 healthy non-smoking children (643 girls and 527 boys), aged 6-18 years. The spiroanalyser Pneumoscreen II (Jaeger) was used to register dynamic lung parameters. Natural logarithmic values of lung volumes, standing or sitting height and age were used in the final regression model. Prediction equations for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), peak expiratory flow, forced expiratory flows when 50 and 75% of FVC has been exhaled, and mean forced expiratory flow over the middle 50% of the FVC for both sexes are presented. In comparison with recent data from European children the reference values were close for FVC, the differences were bigger for FEV1 and forced expiratory flows, especially in taller children.