We read the recent article by Johannessen and colleagues with interest in that they suggest the lower limit of normal (LLN) for FEV 1 expressed as a percent of FVC (FEV 1 %) is above 70% in both sexes regardless of age
Defining the Lower Limits of Normal (LLN) in Spirometry The use of percent predicted when assessing lung function is widely used and an 80% 'cut-off' for a lower limit of normal (LLN) is commonly utilised and considered during diagnosis and monitoring of respiratory disease. However, the 80% of predicted 'cut-off' for what may be considered 'normal' is not based on an FEV1/FVC% FEF25-75% (L/s)* Predicted> Blank: Blank: Blank: Blank: Percent Predicted: Blank: Blank: Blank: Blank: Lower Limit of Normal: Blank: Blank: Blank: Blan A diagnosis established by both a low FEV1/FVC (according to fixed ratio and/or lower limit of normal) and a low FEV1 is strongly associated with clinical outcomes. Guidelines should be reconsidered to require both spirometry abnormalities so as to reduce overdiagnosis of COPD Aggarwal et al. found an overall lower prevalence rate when applying FEV 1 /FVC <0.70 instead of the LLN, 23.6% and 28.2% respectively. 22 This stands in contrast to the other studies, but it should be noted that they included younger subjects
Traditionally, lower 95% confidence intervals calculated from mean values and their variability have been used to define the lower limits of normal (LLN) of the FEV 1 /FVC. 14 Because the distribution of abnormalities has usually been considered normal, these LLN have been calculated from age-declining FEV 1 /FVC predicted mean values less 1.645 times the standard deviation ( SD) of reference. Weighted Cox proportional hazards regression revealed an increased hazard ratio in persons with both fixed ratio and lower limit of normal with a low FEV1 (1.79, p < 0.0001), in those with fixed ratio only with a low FEV1 (1.77, p < 0.0001), in those with abnormal fixed ratio only with a normal FEV1 (1.28, p < 0.0001) compared with persons with no airflow obstruction (reference group). These remained significant after adjusting for demographic variables and other confounding variables. Thus the threshold of Lower Limit of Normal (LLN) was gradually been recommended to establish a diagnosis of COPD [1,6,7]. Using the lower limit of normal for the fev1/fvc ratio reduces the misclassification of airway obstruction. Thorax, 63 (2008), pp. 1046-1051. CrossRef View Record in Scopus Google Scholar. B.H. Culver. How should the lower limit of the normal range be defined? Respir.
The first method used statistically derived lower limit of normal (LLN) standards for spirometry, lung volumes, and D lco measurements to identify normality or abnormality. The second method used an FEV 1 /FVC ratio of 70% Lower Limits of Normal. For years it was known that using a fixed cut-off point across the entire range of ages did not seem to be the best way to assess the spirometry values. The Lower Limits of Normal (LLN) seem to be a better way to assess spirometric values than the fixed 80% rule. LLN is the lower fifth percentile of the Gaussian bell curve: 95% of healthy people can blow better than the. Spirometry Reference Value Calculator. Enter Age, Height, Gender and Race. To see Percent Predicted, you must enter observed FVC, FEV1, and FEF25-75% values in the appropriate boxes FEV1/FVC (ratio) Lower Limit of Normal: Predicted: Upper Limit of Normal: Disclaimer. The GLI software packages are to be used for research, education, training and validation of implementation in software, and not for use in patient treatment. For treatment/diagnostic purposes, please use the GLI reference equations as implemented by medical device companies. References. Stanojevic S, Wade A. In this study, we found that the lower limit of the normal postbronchodilator FEV 1 /FVC exceeded 70% across all ages among healthy never-smokers. Miller and colleagues question the reliability of this result. According to two studies published in 1983, there is a relatively slow cooling of gases within the Vitalograph, and correcting spirometric indexes to BTPS assumes that the spirometer has.
Defining the Lower Limit of Normal for FEV1/ FVC To the Editor : From the Authors : We read the recent article by Johannessen and colleagues (1) We thank Dr. Miller and colleagues for their comments on our with interest in that they suggest the lower limit of normal (LLN) recent article (1). In this study, we found that the lower limit of for FEV1 expressed as a percent of FVC (FEV1%) is above. Lower limit of normal or FEV 1/FVC <0.70 in diagnosing COPD: An evidence-based review Firdaus A.A. Mohamed Hoesein, Pieter Zanen*, Jan-Willem J. Lammers Department of Respiratory Medicine, Division Heart & Lungs, University Medical Center Utrecht, Heidelberglaan 100, HP. F.02.333, PO Box 85500, 3508 GA Utrecht, The Netherlands Received 3 November 2010; accepted 11 January 2011 Available online. Pulmonary Function Test Interpretation (Used in ATS Guidelines) III. Background. Based on Third National Health and Nutrition Examination Survey (NHANES III) PFT data. Calculated the lowest 5% (fifth percentile) cut-offs for FEV1 to FVC, FVC and FEV1. Replaces GOLD Criteria which are less accurate. Miss up to 50% of young adults with. We compared retrospectively the sensitivity and specificity of FEV1/FVC below the lower limit of normal, FEV1/FVC below 0.7, and air trapping and/or hyperinflation by plethysmography to diagnose radiographic obstructive lung disease. We included 455 patients, 80 (17.6%) of whom had radiographic findings of obstructive lung disease. The sensitivities of all 3 diagnostic criteria to diagnose. Ratio (FEV1/FVC) are the most important variables Fifth percentile lower limit of normal (LLN) Chronic Obstructive Pulmonary Disease - continued Total lung capacity (TLC) Body plethsmography Helium dilution Nitrogen washout Course and response to therapy Decline in FEV1 (90 to 150 mL/yr) in smokers Nearly normal rate of FEV1 decline (20 to 30 mL/yr) Chronic Obstructive Pulmonary Disease.
De nieuwe Astma en COPD standaarden zijn uit. Eén van de belangrijkste wijzigingen is het afkappunt wanneer we spreken van obstructie. Bij deze nieuwe interpretatie verlaten we het vaste afkappunt van 0,70 bij de FER-ratio (=FEV1/FVC-ratio) en werken we voortaan met de Lower Limit of Normal. Deze waarde doet meer recht aan de diagnosestelling COPD, omdat ouderen vanaf 60 jaar van nature een. normal or even elevated. A ratio of FEV1/FVC of < 70% is generally taken to indicate obstructive airways disease. Note should be made, however, the as one ages (male >40yrs and females >50yrs), the ratio of FEV 1/FVC tend to drop, and for elderly patients the lower limit of normal (LLN) for FEV 1/FVC may be a more useful indicator of obstruction than an absolute value of 70%. Hence the ATS/ERS. Physicians should use the American Thoracic Society criteria (FEV 1 /FVC ratio less than the lower limit of normal) to diagnose obstructive lung disease in patients younger than 65 years.
A proposed strategy for reducing the misclassification of airway obstruction include the use of the statistically derived lower limit of normal (LLN) for FEV1/FVC, calculated as the fifth percentile of the normal distribution in a healthy population. Some authors addressed the possibility to evaluate lung function through high-resolution CT. In contrast to spirometry, CT imaging may allow for. If the FEV1/FVC ratio is less than the lower limit of normal for the patient, what does that indicate? Obstructive defect is present . If the FEV1/FVC ratio is greater than the lower limit of normal, what does that represent? Restrictive defect or normal. If the FVC is less than the lower limit of normal, what does that represent? Restrictive disease. What confirms the presence of restriction. In addition to a discussion of the diagnostic errors associated with use of the fixed FEV1/FVC ratio of 0.7, this article highlights the misclassification associated with fixed 80%-predicted thresholds for spirometry variables. The authors suggest the fifth-percentile should be used to determine the lower limit of normal for spirometric variables and ratios. PMID: 20522571. Free Full Text. Die globale Initiative GOLD definiert die Obstruktion anhand einfach zu messender spirometrischer Kriterien: der postbronchodilatatorisch gemessene Tiffeneau Index (FEV1/FVC) < 70% oder alternativ FEV1/FVC < als die untere Normgrenze (lower limit of normal, LLN). Je nach Fragestellung können sich noch weitere Untersuchungen anschließen. Liu S, Zhou Y, Liu S, et al. Clinical impact of the lower limit of normal of FEV1/FVC on detecting chronic obstructive pulmonary disease: a follow-up study based on cross-sectional data. Respir Med. 2018;139:27-33. PubMed Google Scholar 49. Orozco-Levi M, Garcia-Aymerich J, Villar J, et al. Wood smoke exposure and risk of chronic obstructive pulmonary disease. Eur Respir J. 2006;27(3):542.
BACKGROUND: Healthy individuals without respiratory symptoms can sometimes present with low FEV1/FVC. The objective of this study was to characterize and compare subjects without symptoms and with reduced FEV1/FVC but normal FEV1 with subjects with mild obstructive lung disease. METHODS: Fifty healthy subjects with FEV1/FVC below the fifth percentile of reference values (normal variants) were. 1/FVC ratio may need to be lowered to 0.65 as a lower limit of normal. Conversely, in people under 45, using a ratio of 0.7 may result in under-diagnosis of airway obstruction. To avoid both of these problems, many experts recommend use of the lower limit of normal for each population. Predicted values are calculated from thousands of normal people and vary with sex, height, age and - 1. Lower Limit of Normal (LLN): the lower limit of normal is based on a statistical analysis of the study population. An FVC, FEV1 or FEV1/FVC ratio above the LLN is considered to be within normal limits. If the FVC, FEV1 and FEV1/FVC ratio are normal, then the test results are normal. If the FVC is normal and the FEV1 or FEV1/FVC ratio are below normal, then this suggests you may have airway.
This interprets to a lower FEV1 and FEV1/FVC ratio. FVC measurement. One of the basic spirometry measurements is FVC, which is the highest total amount of air you can forcefully expire after breathing in as deeply as you can. If your FVC is lower than normal, something is restricting or limiting your breathing. Normal or abnormal results are assessed differently between adults and children. FEV1 is a measurement used to stage and diagnose lung diseases. It measures the amount of breath a person can exhale in one second. Find out more about how it works, what the results mean, and how. (lower limits of normal) DEFINING OBSTRUCTION WITH FEV1/FVC RATIO: FIXED 0.7 CUT-OFF VS. AGE-ADJUSTED LLN. STEP II: IS THE TEST OF ADEQUATE QUALITY? Acceptability and Reproducibility. ACCEPTABILITY Free from artifacts (cough, glottic closure) 1 Free from leaks 2 Good start 3 Good Effort 4 Examine the flow volume loop and the flow time curve. AJRCCM.1994. REPRODUCIBILITY 3 acceptable maneuvers.
Using the lower limit of normal for the FEV1/FVC ratio reduces the misclassification of airway obstructio Forced expiratory ratio (FEV1/FVC)x100: Percentage of FVC expelled in the first second of a forced expiration. Normal in restrictive disease - reduced in obstructive disease. FEF 25-75%: Forced expiratory flow between 25-75%: Average expiratory flow rate at the middle part of forced expiration. It is a more sensitive indication of what is happening in the middle/lower airways, but is not as. Lower limit of normal or FEV1/FVC < 0.70 in diagnosing COPD: an evidence-based review. Mohamed Hoesein FA, Zanen P, Lammers JW. Respir Med, 105(6):907-915, 05 Feb 2011 Cited by: 69 articles | PMID: 21295958. Revie
Interpretation of results. The above Figure shows the observed FEV1 values in relation to the relative limit of longitudinal decline (LLD) (blue line) and two cross-sectional limits: the lower limit of normal (LLN) (burgundy) which represents the lower 5th percentile in healthy non-smokers, and the 0.1th percentile (yellow) which approximates 60% predicted to indicate a moderate airflow.
El uso del cociente FEV1/FVC, por su sencillez, puede favorecer su implementación en la práctica clínica y facilitar el diagnóstico precoz de la enfermedad, aunque su relevancia clínica no está bien establecida, especialmente en el estadio 1 de GOLD, donde puede haber grandes divergencias con otros criterios basados en conceptos estadísticos como el LIN. En un intento de mejorar la. Klein JS, Gamsu G, Webb WR, et al. High-resolution CT diagnosis of emphysema in symptomatic patients with normal chest radiographs and isolated low diffusing capacity. Radiology 1992; 182:817. Park KJ, Bergin CJ, Clausen JL. Quantitation of emphysema with three-dimensional CT densitometry: comparison with two-dimensional analysis, visual. The ATS instead use the lower limit of normal criteria from the fifth lowest percentile of spirometry data reported by the Third National Health and Nutrition Examination Survey (NHANES III). An increased FEV1/FVC ratio is also possible, and this is usually associated with a restrictive lung disease pattern
In their article on the diagnosis of chronic obstructive pulmonary disease (COPD) in primary care, Conway and colleagues state that the diagnosis can be confirmed by a low FEV1/FVC (forced expiratory volume in one second/forced vital capacity) ratio,1 with a ratio <0.70 confirming a diagnosis of pathological airflow limitation. The GOLD (Global Initiative for Chronic Obstructive Lung Disease. FEV1/FVC Lower Limit of Normal Aids Surgery Risk Stratification in COPD. Posted by RT Staff | Jun 8, 2015 | Asthma, COPD, Thoracic Surgery | According to Medwire News, researchers say that using the lower limit of normal of the forced expiration volume in 1 second/forced vital capacity ratio improves risk stratification in patients with COPD undergoing thoracic surgery. Using this.
FEV1/FVC FEV1/FVC is computed from the predicted of FEV1 and FVC of the same source X FEV1/FVC is used for FEV1/VC (or vice versa) LLN of Parameter: This table lists which lower limits of normal (LLN) are provided by the study. If the Lower limit of normal values are not available as an equation, then the values are computed using the following formula: LLN = Predicted - 1.645 * SEE (Standard. Lower limit of normal or FEV1/FVC < 0.70 in diagnosing COPD: an evidence-based review. Mohamed Hoesein FA, Zanen P, Lammers JW. Respir Med, 105(6):907-915, 05 Feb 2011 Cited by: 68 articles | PMID: 21295958. Revie 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 spirom-etry abnormalities so as to reduce overdiagnosis of COPD. Ann Fam Med 2015;13:41-48. doi: 10.1370/afm.1714. INTRODUCTION C hronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic diseases and the cause of. Der untere Grenzwert für den Tiffeneau-Index wird auch lower limit of normal (LLN) genannt. Der LLN wird durch die 5. Perzentile des Frequenzspektrums der in der Referenzpopulation gemessenen Werte bestimmt. Werte unterhalb dieses Grenzwertes gelten - mit einer Irrtumswahrscheinlichkeit von unter 5 % - als pathologisch
In addition, a single center study showed that among individuals with PRISm and TLC above the lower limit of normal (LLN), only 26% had a clinical diagnosis of obstructive lung disease 9 The FEV1/FVC ratio (FEV1%), also known as the Tiffeneau-Pinelli index, is a spirometric parameter and refers to a calculated ratio which represents the proportion of a patients vital capacity that they are able to expire in the first second of forced expiration.. FEV1% is used in the diagnosis and assessment of obstructive (e.g. COPD) and restrictive lung disease Using the lower limit of normal for the FEV1/FVC ratio reduces the misclassification of airway obstruction. Thorax. 2008;63:1046-51. Article CAS PubMed Google Scholar 29. Buist AS, Vollmer WM, McBurnie MA. Worldwide burden of COPD in high- and low-income countries. Part 1. The burden of obstructive lung disease (BOLD) initiative. Int J Tuberc. regardless of age and defines a low FEV1/FVC as less than 70% for everyone The FEV1/FVC Ratio Changes With Age • The FEV1/FVC ratio declines in normal people as they get older ‒An average FEV1/FVC in a 20 year old is 87% ‒An average FEV1/FVC in an 84 year old is 71% • The lower limit of normal in an 84 year old is 59%! • The ATS definition of obstruction takes this age variation into.
If the FVC and the FEV1 are within 80% of the reference value, the results are considered normal. The normal value for the FEV1/FVC ratio is 70% (and 65% in persons older than age 65). When compared to the reference value, a lower measured value corresponds to a more severe lung abnormality. (See table below. Mounting evidence suggests that airway obstruction defined by the lower limit of normal (LLN) of forced expiration volume in 1s (FEV1)/forced vital capacity (FVC) might be an important predictor of mortality in patients with an FEV1/FVC ratio below 0.70. Although better risk stratification for postoperative outcomes in patients with chronic obstructive pulmonary disease (COPD) undergoing. respective lower limits of normal defined by Hankinson and coworkers. We used FEV1/FVC as the gold standard for diagnosing airway obstruction. The severity of airway obstruction was graded into one of four categories; possible normal variant (FEV1>100% predicted), mild (FEV1 70-100% predicted), moderate (FEV1 50-70% predicted), and severe (FEV1 <50% predicted).The sensitivity. High quality example sentences with lower limits of normal in context from reliable sources - Ludwig is the linguistic search engine that helps you to write better in Englis COPD Gold criteria define abnormal FEV1/FVC <0.7; Interpretation via Lower Limit of Normal (LLN) is preferred and used by ATS/ERS guidelines. Lower limit of normal is <5th percentile for ethnicity and age; Swanney (2008) Thorax 63:1046-51 [PubMed] Normal ranges vary by age. Age 8 to 19 years: FEV1/FVC 85%; Age 20 to 39 years: FEV1/FVC 80% ; Age 40 to 59 years: FEV1/FVC 75%; Age 60 to 80.
FEV1:FVC Threshold Identifies Individuals at Risk for Clinically Significant COPD Sheila Jacobs. Share on Facebook; Share on Twitter; Share on LinkedIn ; Share on Reddit; Print; Share by Email; The optimal fixed threshold of 0.71 for discriminating COPD-related events did not differ significantly from the 0.70 threshold but was more accurate than the lower limit of normal threshold. The use of. The normal values for FEV1 vary from person to person. They're based on standards for an average healthy person of your age, race, height, and gender. Each person has their own predicted FEV1 value
reduced FEV1/FVC defined as less than the lower limit of normal); or Patient is currently dependent on maintenance therapy with oral corticosteroids for the treatment of asthma and ; o One of the following: Asthma is an eosinophilic phenotype as defined by a baseline (prereslizumab) peripheral blood eosinophil level of - ≥ 400 cells/μL within the past 4 weeks; or Patient is currently. Lower limit of normal or FEV1/FVC < 0.70 in diagnosing COPD: an evidence-based review. Mohamed Hoesein FA, Zanen P, Lammers JW. Respir Med, 105(6):907-915, 05 Feb 2011 Cited by: 70 articles | PMID: 21295958. Revie The authors consider a COPD diagnosis by both lower limit of normal (LLN) and the fixed ratio (FR), that is FEV1/FVC<0.7, as concordant (LLN+FR+) and subjects who are FR+LLN- as discordant. Their data show that the discordant group have lower CAT score and lower BODE index suggesting that this group likely has other co-morbidities. As expected, the discordant group is older, more male. Fixed ratio or lower limit of normal for the FEV1 /VC ratio: relation to symptoms and extended lung function tests. / Wollmer, Per; Frantz, Sophia; Engström, Gunnar; Dencker, Magnus; Löfdahl, Claes-Göran; Nihlén, Ulf. In: Clinical Physiology and Functional Imaging, 2015. Research output: Contribution to journal › Article. Harvard. Wollmer, P, Frantz, S, Engström, G, Dencker, M, Löfdahl.
Diagnosis of airways obstruction should be based on symptoms and an FEV1/FVC ratio below the lower limit of normal Author: Philip H Quanjer, Irene Steenbruggen, Jan Willem van den Berg Created Date: 20160128113542
The predicted FEV1/FVC ratios decrease progressively with age in adults.6 A fixed FEV1/FVC ratio thus overestimates airway obstruction in the elderly and underestimates it in young adults.7,8 Obstructive abnormality is most accurately diagnosed when a reduced FEV1/FVC ratio is below lower limit of normal (LLN) i.e. the 5th percentile of the predicted value.9 The post-bronchodilator reference. European Respiratory Society and American Thoracic Society favour the use of the fifth percentile of the age-related FEV1 /FVC ratio (the lower limit of normal, LLN). The purpose of this study was to analyse extensive lung function tests in groups of subjects fulfilling none, either or both of the spirometric criteria for COPD. From a previous population-based study, 450 subjects were examined.
The lower limit of normal (LLN) threshold was evaluated as an alternative COPD definition. The LLN was defined as the lower fifth percentile for predicted FEV1/FVC. The reduction in FEV1 was used to stage the degree of obstruction: GOLD stage I was defined as FEV1 ≥ 80% predicted, GOLD stage II as FEV1 50-79% predicted, GOLD stage III as FEV1. Lower limit of normal or FEV1/FVC < 0.70 in diagnosing COPD: an evidence-based review. Respir Med. 2011; 105(6):907-15 (ISSN: 1532-3064) Mohamed Hoesein FA; Zanen P; Lammers JW. AIM: To review the currently available literature comparing the FEV1/FVC <LLN with a fixed value of FEV1/FVC < 0.70 in diagnosing airflow obstruction in subjects aged >40 years. METHODS: A structured MEDLINE, EMBASE. Best test FEV1/FVC ratio below Lower Limit of Normal and/or less than 70% Target: Both males and females 6 YEARS - 79 YEARS. Code or Value Value Description Count Cumulative Skip to Item; 1: Yes: 842: 842: 2: No: 5853: 6695. Missing: 800: 7495: SPXBSTAT - Spirometry Second Test Status Variable Name: SPXBSTAT SAS Label: Spirometry Second Test Status English Text: Spirometry Second Test Status. Flow volume loops and time volume plots for each case are available if desired. Each answer may be appear once, more than once, or not at all. Reference values for FEV1 and FVC are predicted from the equations of Morris. The FEV1/FVC reference values are the lower limit of normal as defined by Crapo Lower limit of normal range (LLN) adalah preferensi cut off untuk mengidentifikasi nilai abnormal pada pemeriksaan spirometri. Untuk PPOK, dinyatakan rasio FEV1/FVC < 0,70, atau nilai FEV1 <80% post pemberian bronkodilator dimana cut off ini dinyatakan sebagai LLN
Using the lower limit of normal for the FEV1/FVC ratio reduces the misclassification of airway obstruction. Thorax. 2008 Dec; 63(12):1046-51. T. Abstract . AIM. The prevalence of airway obstruction varies widely with the definition used. OBJECTIVES. To study differences in the prevalence of airway obstruction when applying four international guidelines to three population samples using four. In addition, the FEV1/FVC ratio is only 0.68, less than the lower limit of normal of the predicted value minus 8 (80-8 = 72) for this male patient. A low FEV1 and FVC with a decreased FEV1/FVC ratio is consistent with a diagnosis of air-flow obstruction. With an FEV1 of 64% predicted this would be classified as moderate airflow obstruction. In addition, the FVC improves by 0.81 L (25%. A diagnosis established by both a low FEV1/FVC (according to fixed ratio and/or lower limit of normal) and a low FEV1 is strongly associated with clinical outcomes. Guidelines should be reconsidered to require both spirom-etry abnormalities so as to reduce overdiagnosis of COPD. Ann Fam Med 2015;13:41-48. doi: 10.1370/afm.1714
Eine obstruktive Ventilationsstörung, charakteristisch für die Erkrankungen Asthma und COPD, wird spirometrisch durch eine Verminderung des Tiffeneau-Index (FEV1/FVC) auf Werte unterhalb des 5. Perzentils (entsprechend dem unteren Grenzwert, »lower limit of normal«, LLN) definiert. Eine verminderte Vitalkapazität kann Ausdruck einer restriktiven Ventilationsstörung sein, die durch eine. To review the currently available literature comparing the FEV 1 /FVC <LLN with a fixed value of FEV 1 /FVC <0.70 in diagnosing airflow obstruction in subjects aged >40 years.A structured MEDLINE, EMBASE and Cochrane search of English-language literature was conducted. Studies comparing prevalence rates according to the LLN and a fixed value were included The normal value for the FEV1/FVC ratio is above 0.75. Values lower than 0.70 are suggestive of airflow limitation with an obstructive pattern whilst in restrictive lung diseases, this ratio is normal or high. FEV1/FVC Ratios <70% are indicative of chronic obstructive pulmonary disease (COPD) or lower than 65% in patients older than 65 years
Fixed ratio or lower limit of normal for the FEV1 /VC ratio: relation to symptoms and extended lung function tests. / Wollmer, Per; Frantz, Sophia; Engström, Gunnar; Dencker, Magnus; Löfdahl, Claes-Göran; Nihlén, Ulf. I: Clinical Physiology and Functional Imaging, 2015. Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrif Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (FEV1/FVC <70%) are extensively used for diagnosis of chronic obstructive lung disease in heart failure (HF). The American Thoracic Society (ATS)/European Respiratory Society (ERS) recommends the use of age- and gender-specific lower limit of normal (LLN) for FEV1/FVC Clinical Relevance of Fixed Ratio vs Lower Limit of Normal of FEV1/FVC in COPD: Patient-Reported Outcomes From the CanCOLD Cohort By W. van Dijk, W. Tan, P. Li, B. Guo, S. Li, A. Benedetti, J. Bourbeau and null nul Cut-off value of FEV1/FEV6 as a surrogate for FEV1/FVC for detecting airway obstruction in a Korean population. Overview of attention for article published in International Journal of Chronic Obstructive Pulmonary Disease, August 2016 . Altmetric Badge. Mentioned by twitter 1 tweeter. Citations dimensions_citation 10 Dimensions. Readers on mendeley 19 Mendeley. What is this page? Summary. We undertook systematic case finding for COPD in primary care using the fixed ratio (FR) criterion (forced expiratory volume in 1 s/forced vital capacity [FEV1/FVC] <0.7) for defining airflow obstruction and also using the lower limit of normal (LLN). We then compared the clinical characteristics of those identified by the 2 criteria