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Reference values for spirometry - report from the Obstructive Lung Disease in Northern Sweden studies.

Backman H, Lindberg A, Odén A, Ekerljung L, Hedman L, Kainu A, Sovijärvi A, Lundbäck B, Rönmark E - Eur Clin Respir J (2015)

Bottom Line: This modelling approach resulted in unbiased estimates of the spirometric outcomes, and the obtained estimates were appropriate not only for the northern Sweden sample but also for the south-western Sweden sample.Furthermore, the evaluation based on the south-western Sweden sample indicates a high external validity.The comparison with GLI brought further evidence to the consensus that, when available, appropriate local population-specific reference values may be preferred.

View Article: PubMed Central - PubMed

Affiliation: The OLIN Unit, Division of Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.

ABSTRACT

Background: Abnormal lung function is commonly identified by comparing observed spirometric values to corresponding reference values. It is recommended that such reference values for spirometry are evaluated and updated frequently. The aim of this study was to estimate new reference values for Swedish adults by fitting a multivariable regression model to a healthy non-smoking general population sample from northern Sweden. Further aims were to evaluate the external validity of the obtained reference values on a contemporary sample from south-western Sweden, and to compare them to the Global Lung Function Initiative (GLI) reference values.

Method: Sex-specific multivariable linear regression models were fitted to the spirometric data of n=501 healthy non-smoking adults aged 22-91 years, with age and height as predictors. The models were extended to allow the scatter around the outcome variable to depend on age, and age-dependent spline functions were incorporated into the models to provide a smooth fit over the entire age range. Mean values and lower limits of normal, defined as the lower 5th percentiles, were derived.

Result: This modelling approach resulted in unbiased estimates of the spirometric outcomes, and the obtained estimates were appropriate not only for the northern Sweden sample but also for the south-western Sweden sample. On average, the GLI reference values for forced expiratory volume in one second (FEV1) and, in particular, forced expiratory vital capacity (FVC) were lower than both the observed values and the new reference values, but higher for the FEV1/FVC ratio.

Conclusion: The evaluation based on the sample of healthy non-smokers from northern Sweden show that the Obstructive Lung Disease in Northern Sweden reference values are valid. Furthermore, the evaluation based on the south-western Sweden sample indicates a high external validity. The comparison with GLI brought further evidence to the consensus that, when available, appropriate local population-specific reference values may be preferred.

No MeSH data available.


Related in: MedlinePlus

(a–f) Sex- and age-dependent decline in the OLIN reference values (mean and LLN) in comparison with GLI. The predicted mean and LLN for the OLIN and the GLI reference values are plotted against age, for FEV1, FVC and the FEV1/FVC ratio, respectively. Figures (a), (b) and (c) display predicted values for a 165 cm tall woman, while (d), (e) and (f) display predicted values for a 180 cm tall man.
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Figure 0002: (a–f) Sex- and age-dependent decline in the OLIN reference values (mean and LLN) in comparison with GLI. The predicted mean and LLN for the OLIN and the GLI reference values are plotted against age, for FEV1, FVC and the FEV1/FVC ratio, respectively. Figures (a), (b) and (c) display predicted values for a 165 cm tall woman, while (d), (e) and (f) display predicted values for a 180 cm tall man.

Mentions: To make further comparisons to the GLI reference values, the predicted reference values of FEV1, FVC and the FEV1/FVC ratio (mean and LLN) for a woman and man of average height are plotted by age in Fig. 2a–f. The comparisons showed that for a man of average height, meanGLI for both FEV1 and, in particular, for FVC, were lower than meanOLIN across the ages 22–86 years. For a woman of average height, meanOLIN and meanGLI for FEV1 were similar, but meanGLI FVC is constantly lower than meanOLIN FVC. Consequently, the meanGLI FEV1/FVC ratio was also consistently lower than the meanOLIN for the woman. For a woman of average height, the LLNGLI and LLNOLIN for the FEV1/FVC ratio was well in concordance throughout the age span, but less so for FEV1 and FVC where LLNGLI was consistently lower than LLNOLIN. The pattern was somewhat different for the average height man, where the gap between LLNGLI and LLNOLIN increased with increasing age for all three spirometric indices. LLNGLI for the FEV1/FVC ratio reached below 0.7 at the age between 46 and 47 years for a woman of average height and at the age 39–40 years for a man of average height. The corresponding ages when LLNOLIN reached below 0.7 for the FEV1/FVC ratio are 43–44 years for the woman and 53–54 years for the man. Both the LLNGLI and LLNOLIN for FEV1/FVC reached below 0.7 in earlier stages in life for taller subjects compared to for shorter subjects of both sexes.


Reference values for spirometry - report from the Obstructive Lung Disease in Northern Sweden studies.

Backman H, Lindberg A, Odén A, Ekerljung L, Hedman L, Kainu A, Sovijärvi A, Lundbäck B, Rönmark E - Eur Clin Respir J (2015)

(a–f) Sex- and age-dependent decline in the OLIN reference values (mean and LLN) in comparison with GLI. The predicted mean and LLN for the OLIN and the GLI reference values are plotted against age, for FEV1, FVC and the FEV1/FVC ratio, respectively. Figures (a), (b) and (c) display predicted values for a 165 cm tall woman, while (d), (e) and (f) display predicted values for a 180 cm tall man.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4629723&req=5

Figure 0002: (a–f) Sex- and age-dependent decline in the OLIN reference values (mean and LLN) in comparison with GLI. The predicted mean and LLN for the OLIN and the GLI reference values are plotted against age, for FEV1, FVC and the FEV1/FVC ratio, respectively. Figures (a), (b) and (c) display predicted values for a 165 cm tall woman, while (d), (e) and (f) display predicted values for a 180 cm tall man.
Mentions: To make further comparisons to the GLI reference values, the predicted reference values of FEV1, FVC and the FEV1/FVC ratio (mean and LLN) for a woman and man of average height are plotted by age in Fig. 2a–f. The comparisons showed that for a man of average height, meanGLI for both FEV1 and, in particular, for FVC, were lower than meanOLIN across the ages 22–86 years. For a woman of average height, meanOLIN and meanGLI for FEV1 were similar, but meanGLI FVC is constantly lower than meanOLIN FVC. Consequently, the meanGLI FEV1/FVC ratio was also consistently lower than the meanOLIN for the woman. For a woman of average height, the LLNGLI and LLNOLIN for the FEV1/FVC ratio was well in concordance throughout the age span, but less so for FEV1 and FVC where LLNGLI was consistently lower than LLNOLIN. The pattern was somewhat different for the average height man, where the gap between LLNGLI and LLNOLIN increased with increasing age for all three spirometric indices. LLNGLI for the FEV1/FVC ratio reached below 0.7 at the age between 46 and 47 years for a woman of average height and at the age 39–40 years for a man of average height. The corresponding ages when LLNOLIN reached below 0.7 for the FEV1/FVC ratio are 43–44 years for the woman and 53–54 years for the man. Both the LLNGLI and LLNOLIN for FEV1/FVC reached below 0.7 in earlier stages in life for taller subjects compared to for shorter subjects of both sexes.

Bottom Line: This modelling approach resulted in unbiased estimates of the spirometric outcomes, and the obtained estimates were appropriate not only for the northern Sweden sample but also for the south-western Sweden sample.Furthermore, the evaluation based on the south-western Sweden sample indicates a high external validity.The comparison with GLI brought further evidence to the consensus that, when available, appropriate local population-specific reference values may be preferred.

View Article: PubMed Central - PubMed

Affiliation: The OLIN Unit, Division of Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.

ABSTRACT

Background: Abnormal lung function is commonly identified by comparing observed spirometric values to corresponding reference values. It is recommended that such reference values for spirometry are evaluated and updated frequently. The aim of this study was to estimate new reference values for Swedish adults by fitting a multivariable regression model to a healthy non-smoking general population sample from northern Sweden. Further aims were to evaluate the external validity of the obtained reference values on a contemporary sample from south-western Sweden, and to compare them to the Global Lung Function Initiative (GLI) reference values.

Method: Sex-specific multivariable linear regression models were fitted to the spirometric data of n=501 healthy non-smoking adults aged 22-91 years, with age and height as predictors. The models were extended to allow the scatter around the outcome variable to depend on age, and age-dependent spline functions were incorporated into the models to provide a smooth fit over the entire age range. Mean values and lower limits of normal, defined as the lower 5th percentiles, were derived.

Result: This modelling approach resulted in unbiased estimates of the spirometric outcomes, and the obtained estimates were appropriate not only for the northern Sweden sample but also for the south-western Sweden sample. On average, the GLI reference values for forced expiratory volume in one second (FEV1) and, in particular, forced expiratory vital capacity (FVC) were lower than both the observed values and the new reference values, but higher for the FEV1/FVC ratio.

Conclusion: The evaluation based on the sample of healthy non-smokers from northern Sweden show that the Obstructive Lung Disease in Northern Sweden reference values are valid. Furthermore, the evaluation based on the south-western Sweden sample indicates a high external validity. The comparison with GLI brought further evidence to the consensus that, when available, appropriate local population-specific reference values may be preferred.

No MeSH data available.


Related in: MedlinePlus