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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

Study flow chart.
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Figure 0001: Study flow chart.

Mentions: As a part of the Obstructive Lung Disease in Northern Sweden (OLIN) studies, 1,016 randomly selected respondents from a large postal questionnaire survey in 2006 (33) were invited to clinical examinations in 2008–2009. Of them, 737 subjects (72.5%) aged 21–86 years participated in structured interviews and spirometry (34). In 2011–2013, 738 additional healthy non-smokers according to the 2006 questionnaire survey were invited to identical examinations, and 448 subjects (60.6%) aged 25–91 years participated (17). The study flow chart is illustrated in Fig. 1. Information about respiratory diseases and symptoms, other diseases, and smoking history was collected at the interview. The study was approved by the Regional Ethical Review Board at Umeå University, Sweden.


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)

Study flow chart.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 0001: Study flow chart.
Mentions: As a part of the Obstructive Lung Disease in Northern Sweden (OLIN) studies, 1,016 randomly selected respondents from a large postal questionnaire survey in 2006 (33) were invited to clinical examinations in 2008–2009. Of them, 737 subjects (72.5%) aged 21–86 years participated in structured interviews and spirometry (34). In 2011–2013, 738 additional healthy non-smokers according to the 2006 questionnaire survey were invited to identical examinations, and 448 subjects (60.6%) aged 25–91 years participated (17). The study flow chart is illustrated in Fig. 1. Information about respiratory diseases and symptoms, other diseases, and smoking history was collected at the interview. The study was approved by the Regional Ethical Review Board at Umeå University, Sweden.

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