uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Underestimation of airflow obstruction among young adults using FEV1/FVC<70% as a fixed cut-off: a longitudinal evaluation of clinical and functional outcomes
Show others and affiliations
2008 (English)In: Thorax, ISSN 0040-6376, Vol. 63, no 12, 1040-1045 p.Article in journal (Refereed) Published
Abstract [en]

Background: Early detection of airflow obstruction is particularly important among young adults because they are more likely to benefit from intervention. Using the forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) (FEV1/FVC) <70% fixed ratio, airflow obstruction may be underdiagnosed. The lower limit of normal (LLN), which is statistically defined by the lower fifth percentile of a reference population, is physiologically appropriate but it still needs a clinical validation.Methods: To evaluate the characteristics and longitudinal outcomes of subjects misidentified as normal by the fixed ratio with respect to the LLN, 6249 participants (aged 20-44 years) in the European Community Respiratory Health Survey were examined and divided into three groups (absence of airflow obstruction by the LLN and the fixed ratio; presence of airflow obstruction only by the LLN; presence of airflow obstruction by the two criteria) for 1991-1993. LLN equations were obtained from normal non-smoking participants. A set of clinical and functional outcomes was evaluated in 1999-2002.Results: The misidentified subjects were 318 (5.1%); only 45.6% of the subjects with airflow obstruction by the LLN were also identified by the fixed cut-off. At baseline, FEV1 (107%, 97%, 85%) progressively decreased and bronchial hyperresponsiveness (slope 7.84, 6.32, 5.57) progressively increased across the three groups. During follow-up, misidentified subjects had a significantly higher risk of developing chronic obstructive pulmonary disease and a significantly higher use of health resources (medicines, emergency department visits/hospital admissions) because of breathing problems than subjects without airflow obstruction (p<0.001).Conclusions: Our findings show the importance of using statistically derived spirometric criteria to identify airflow obstruction.

Place, publisher, year, edition, pages
2008. Vol. 63, no 12, 1040-1045 p.
National Category
Medical and Health Sciences
URN: urn:nbn:se:uu:diva-16794DOI: 10.1136/thx.2008.095554ISI: 000261033800005PubMedID: 18492741OAI: oai:DiVA.org:uu-16794DiVA: diva2:44565
Available from: 2008-06-04 Created: 2008-06-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Janson, Christer
By organisation
Respiratory Medicine and Allergology
In the same journal
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 155 hits
ReferencesLink to record
Permanent link

Direct link