Lung function reference values in different German populations

Background: Spirometry is a frequently performed lung function test and an important tool in medical surveillance examinations of pulmonary diseases. The interpretation of lung function relies on the comparison to reference values derived from a healthy population. The study aim was to compare the lung function data of three representative population-based German studies (Study of Health in Pomerania [SHIP-1], Cooperative Health Research in the Region of Augsburg [KORA-S3] and European Community Respiratory Health Survey Erfurt [ECRHS-I Erfurt]) with existing European spirometry reference values and to establish a new set of comprehensive German prediction equations.

Methods: Spirometry was performed in 4133 participants of three population-based surveys using almost identical standardised methods. Current and former smokers, subjects with cardiopulmonary disorders or on medication with potential influence on lung function were excluded. Sex specific prediction equations were established by quantile regression analyses. Comparison was performed to existing European reference values.

Results: The healthy reference sample consisted of 1302 (516 male) individuals, aged 20-80 years. Sex specific comprehensive prediction equations adjusted for age and height are provided. Significant differences were found in comparison to previous studies with pronounced lower values of the current population if applying historic prediction equations.

Conclusion: The results contribute to the interpretation of lung function examination in providing a comprehensive set of spirometry reference values obtained in a large number of healthy volunteers. Whereas the differences in between the investigated studies are negligible, striking divergence was detected in comparison to historic and recent European spirometry prediction values.