The need to change the method for defining mild airway obstruction

Quanjer, Philip H.; Enright, Paul; Miller, Martin; Stocks, Janet; Ruppel, Gregg; Swanney, Maureen P.; Crapo, Robert O.; Pedersen, Ole F.; Falaschetti, Emanuela; Schouten, Jan P.; Jensen, Robert L.

doi:10.1183/09031936.00135110

Cited by 62 publications

(61 citation statements)

References 35 publications

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“…The latter lower limit was arbitrarily selected because of its simplicity, and because it constituted a limit that would not vary with the prediction equation used. Many investigators have documented that the GOLD criterion for defining airway obstruction can result in marked overestimation of the prevalence of airway obstruction in subjects aged o45 years, which may lead to unnecessary medical expenditure and to underestimation in younger adults [5]. This is because using a fixed ratio of 0.70 ignores both the natural decline of the FEV1/(F)VC ratio with age and the sex differences observed in a normal population.…”

Section: Introductionmentioning

confidence: 94%

“…The age bias has created recent discussion and controversy about the criteria used to define airways obstruction [5,[13][14][15][16][17][18][19][20][21]. The ATS and ERS advocate use of the fifth percentile of FEV1/FVC from a healthy population as the LLN [3], whereas the GOLD group adopted a fixed 0.70 cut-off value for the FEV1/FVC ratio because of its simplicity and independence of different prediction equations [4].…”

Section: Discussionmentioning

confidence: 99%

“…The ATS and ERS advocate use of the fifth percentile of FEV1/FVC from a healthy population as the LLN [3], whereas the GOLD group adopted a fixed 0.70 cut-off value for the FEV1/FVC ratio because of its simplicity and independence of different prediction equations [4]. The GOLD criterion for airway obstruction, by ignoring sex differences and the natural decline of the FEV1/FVC ratio with age to well below 0.70, leads to a .50% overestimation of the prevalence rate of airway obstruction in subjects aged o45 years and to significant underestimates in younger adults [5]. These findings are corroborated in Age group years the present study ( fig.…”

Section: Discussionmentioning

confidence: 99%

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Grading the severity of airways obstruction: new wine in new bottles

Quanjer

Pretto

Brazzale

et al. 2013

European Respiratory Journal

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116

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The objective of this study was to redesign the current grading of obstructive lung disease so that it is clinically relevant and free of biases related to age, height, sex and ethnic group.Spirometric records from 17 880 subjects (50.4% female) from hospitals in Australia and Poland, and 21 191 records (53.0% female) from two epidemiological studies (age range 18-95 years) were analysed. We adopted the American Thoracic Society(ATS)/European Respiratory Society (ERS) criteria for airways obstruction based on an forced expiratory volume in 1 s (FEV1)/(forced) vital capacity ((F)VC) ratio below the fifth percentile and graded the severity of pulmonary function impairment using z-scores for FEV1, which signify how many standard deviations a result is from the mean predicted value.Using the lower limit of normal for FEV1/(F)VC and z-scores for FEV1 of -2, -2.5, -3 and -4 to delineate severity grades of airflow limitation leads to close agreement with ATS/ERS severity classifications and removes age, sex and height related bias.The new classification system is simple, easily memorised and clinically valid. It retains previously established associations with clinical outcomes and avoids biases due to the use of per cent predicted FEV1. Combined with the Global Lung Function prediction equations it provides a worldwide diagnostic standard, free of bias due to age, height, sex and ethnic group. @ERSpublications Using FEV1 z-scores to classify severity of airways obstruction is clinically valid and overcomes bias inherent in % pred

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Section: Introductionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Grading the severity of airways obstruction: new wine in new bottles

Quanjer

Pretto

Brazzale

et al. 2013

European Respiratory Journal

Self Cite

123

116

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“…The other measure is the FEV 1 /FVC ratio below the 5th percentile, in other Wouter van Dijk, MD, PhD 1,2 Wan Tan, MD 3 words, below the lower limit of normal (LLN). 1,[11][12][13][14][15][16][17] Prevalence studies have shown discordance between the fixed ratio and LLN, suggesting potential overdiagnosis by the former or underdiagnosis by the latter. 3,4,8,18,19 This controversy persists because of the absence of a reference standard for the diagnosis of COPD.…”

Section: Introductionmentioning

confidence: 99%

Clinical Relevance of Fixed Ratio vs Lower Limit of Normal of FEV1/FVC in COPD: Patient-Reported Outcomes From the CanCOLD Cohort

Dijk

Tan

et al. 2015

The Annals of Family Medicine

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PURPOSEThe way in which spirometry is interpreted can lead to misdiagnosis of chronic obstructive pulmonary disease (COPD) resulting in inappropriate treatment. We compared the clinical relevance of 2 criteria for defining a low ratio of forced expiratory volume in 1 second to forced vital capacity (FEV 1 /FVC): the fixed ratio and the lower limit of normal. METHODSWe analyzed data from the cross-sectional phase of the populationbased Canadian Cohort of Obstructive Lung Disease (CanCOLD) study. We determined associations of the spirometric criteria for airflow limitation with patientreported adverse outcomes, including respiratory symptoms, disability, health status, exacerbations, and cardiovascular disease. Sensitivity analyses were used to explore the impact of age and severity of airflow limitation on these associations. RESULTSWe analyzed data from 4,882 patients aged 40 years and older. The prevalence of airflow limitation was 17% by fixed ratio and 11% by lower limit of normal. Patients classified as having airflow limitation by fixed ratio only had generally small, nonsignificant increases in the odds of adverse outcomes. Patients having airflow limitation based on both fixed ratio and lower limit of normal had larger, significant increases in odds. But strongest associations were seen for patients who had airflow limitation by both fixed ratio and lower limit of normal and also had a low FEV 1 , defined as one less than 80% of the predicted value. CONCLUSIONSOur results suggest that use of the fixed ratio alone may lead to misdiagnosis of COPD. A diagnosis established by both a low FEV 1 /FVC (according to fixed ratio and/or lower limit of normal) and a low FEV 1 is strongly associated with clinical outcomes. Guidelines should be reconsidered to require both spirometry abnormalities so as to reduce overdiagnosis of COPD.

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“…The nearest is the use of the European Coal and Steel Workers Population to provide percent predicted FEV 1 values; however, this population was standardised over 20 years ago and is based on a working white European population without ethnic minorities. [11][12][13] Similarly, younger people (age 30-40 years) with larger FVC values and greater respiratory reserve may already have sustained COPD-type damage to their lungs before they reach the <0.7 ratio threshold, so at this end of the age range there is a risk of under-diagnosis of COPD. 13 The debate regarding the diagnosis of COPD is more than just a debate over spirometry thresholds.…”

Section: Ps9mentioning

confidence: 99%