Abstract
Background: Commonly used reference values for spirometry, such as the European Community for Steel and Coal (ECSC), are too low for the Nordic countries, including Norway, Sweden and Finland. The GLI reference values are currently endorsed by several respiratory societies including the ERS, but applicability evaluations from European countries are scarce and therefore requested.
Aim: To evaluate whether the GLI reference values are applicable in the Nordic countries.
Methods: During 1998-2013, general population samples in different regions of the Nordic countries were examined clinically, and healthy non-smoking subjects were identified. The total sample size for healthy non-smoking subjects were n=1000 (18-80y, 61% women) in four regions in Finland, and n=501 (22-91y, 49% women) and n=366 (17-78y, 52% women) in northern and south-western Sweden, respectively. GLI predicted values and Z-scores for Forced Expiratory Volume in the first second (FEV1) and Forced Vital Capacity (FVC) were calculated and compared across regions, ages and sex.
Results: The GLI predicted values for FEV1 and FVC were lower compared to the current realities in all six regions. These discrepancies were observed both for men and women and across all ages. The discrepancies were most pronounced for FVC. Mean FVC as % of GLI reference values were, for men and women respectively, 106.2% and 105.1% in Finland, 102.9% and 104.2% in south-western Sweden and 104.1% and 105.9% in northern Sweden.
Conclusions: The choice of reference values is crucial for correct interpretation of results from spirometry. The GLI reference values are too low for the Nordic countries.
- Copyright ©ERS 2015