scholarly journals The lower limit of normal versus a fixed ratio to assess airflow limitation: will the debate ever end?

2018 ◽  
Vol 51 (3) ◽  
pp. 1800403 ◽  
Author(s):  
Lewis J. Smith
Keyword(s):  
Lower Limit ◽  
Fixed Ratio ◽  
Airflow Limitation ◽  
Lower Limit Of Normal

scholarly journals Young and middle-aged adults with airflow limitation according to lower limit of normal but not fixed ratio have high morbidity and poor survival: a population-based prospective cohort study

2018 ◽  
Vol 51 (3) ◽  
pp. 1702681 ◽  
Author(s):  
Yunus Çolak ◽  
Shoaib Afzal ◽  
Børge G. Nordestgaard ◽  
Jørgen Vestbo ◽  
Peter Lange
Keyword(s):  
Heart Failure ◽  
Lower Limit ◽  
Fixed Ratio ◽  
Airflow Limitation ◽  
Middle Aged ◽  
General Population Study ◽  
Increased Risk ◽  
All Cause Mortality ◽  
Middle Aged Adults ◽  
Lower Limit Of Normal

A presumed consequence of using a fixed ratio for the definition of airflow limitation (AFL) has been overdiagnosis among older individuals and underdiagnosis among younger individuals. However, the prognosis of younger individuals with potentially underdiagnosed AFL is poorly described. We hypothesised that potential underdiagnosis of AFL at a younger age is associated with poor prognosis.We assigned 95 288 participants aged 20–100 years from the Copenhagen General Population Study into the following groups: individuals without AFL with forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ≥0.70 and ≥lower limit of normal (LLN) (n=78 779, 83%); individuals with potentially underdiagnosed AFL with FEV1/FVC ≥0.70 and <LLN (n=1056, 1%); individuals with potentially overdiagnosed AFL with FEV1/FVC <0.70 and ≥LLN (n=3088, 3%); and individuals with AFL with FEV1/FVC <0.70 and <LLN (n=12 365, 13%). We assessed risk of exacerbations, pneumonias, ischaemic heart disease, heart failure and all-cause mortality. Median follow-up was 6.0 years (range: 2 days–11 years).Compared to individuals without AFL, individuals with potentially underdiagnosed AFL had an increased risk of morbidity and mortality with age- and sex-adjusted hazard ratios (HR) of 2.7 (95% CI: 1.7–4.5) for pneumonias, 2.3 (95% CI: 1.2–4.5) for heart failure, and 3.1 (95% CI: 2.1–4.6) for all-cause mortality.Young and middle-aged adults with AFL according to LLN but not fixed ratio experience increased respiratory and cardiovascular morbidity and early death.

Agreement Between Fixed-Ratio and Lower Limit of Normal Spirometry Interpretation Protocols Decreases With Age

2013 ◽  
Vol 55 (7) ◽  
pp. 802-808 ◽  
Author(s):  
Marek A. Mikulski ◽  
Alicia K. Gerke ◽  
Spencer Lourens ◽  
Thomas Czeczok ◽  
Nancy L. Sprince ◽  
...  
Keyword(s):  
Lower Limit ◽  
Fixed Ratio ◽  
Lower Limit Of Normal

Respiratory Symptoms Do Not Differ When Defining COPD By Fixed Ratio Or Lower Limit Of Normal

2010 ◽  
Author(s):  
Michael B. Drummond ◽  
David M. Shade ◽  
Cristine E. Berry ◽  
Meredith C. McCormack ◽  
Nadia N. Hansel ◽  
...  
Keyword(s):  
Lower Limit ◽  
Respiratory Symptoms ◽  
Fixed Ratio ◽  
Lower Limit Of Normal

Fixed ratio or lower limit of normal for the FEV1/VC ratio: relation to symptoms and extended lung function tests

2015 ◽  
Vol 37 (3) ◽  
pp. 263-269 ◽  
Author(s):  
Per Wollmer ◽  
Sophia Frantz ◽  
Gunnar Engström ◽  
Magnus Dencker ◽  
Claes-Göran Löfdahl ◽  
...  
Keyword(s):  
Lung Function ◽  
Lower Limit ◽  
Fixed Ratio ◽  
Lung Function Tests ◽  
Function Tests ◽  
Lower Limit Of Normal
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