慢阻肺中第一秒与六秒用力呼气容积比值应用研究

目的探讨第1秒用力呼气容积与6秒用力呼气容积比值（FEV1／FEV6）在慢性阻塞性肺疾病（COPD）诊断方面的临床价值。方法对120例COPD稳定期患者和80例健康者进行肺量测定,前者依据中华医学会制定的《慢性阻塞性肺疾病诊治指南（2007年修订版）》进行分级,分为COPDI-Ⅱ级组、Ⅲ-Ⅳ级组。结果COPDI-Ⅱ级组FEV1／pre、FEV1／FVC、FEV1／FEV6较对照组明显降低,而COPI）Ⅲ-Ⅳ级组与对照组相比,FVC／pre、FEV6／pre、FEV1／pre、FEV1／FVC、FEV1／FEV1显著降低。COPDI-Ⅱ级组FEV1／pre、FVC／pre下降幅度比FEV1／FVC、FEV1／FEV6低;在COPDⅢ-Ⅳ级组FEV,／pre、FVC／pre的下降幅度比FEV。／FVC、FEV,／FEV。的下降幅度要高。COPDⅢ-Ⅳ级组的CV[FVC]高于COPDI-Ⅱ级组和对照组。FEV1／FEV6和FEV1／FVC呈显著正相关。结论相比FVC,FEV6有着更好的重复性,而FEV1／FEV6和FEV1／FVC也有着显著的相关性,同样可以准确反映气流受限,且测试更为简单。     

第三秒用力呼气容积/用力肺活量下降在早期轻度气道功能障碍中的临床意义

目的探讨第三秒用力呼气容积(FEV3)/用力肺活量(FVC)在早期轻度气道功能障碍中的临床意义。方法收集294例肺功能检查患者并分为3组。正常组164例,第一秒用力呼气容积(FEV1)/FVC、FEV3/FVC均正常; FEV3组39例,仅FEV3/FVC降低,但FEV1/FVC正常; FEV1组91例,FEV1/FVC降低。比较各组一般资料及肺功能指标。结果①正常组平均年龄及吸烟比例显著小于FEV3组(P<0. 05); FEV3组与FEV1组相比,平均年龄及吸烟比例差异无统计学意义(P>0. 05)。②FEV3组与正常组相比及FEV1组与FEV3组相比,FEV1%pred、FEV1/FVC较低,肺总量(TLC)、残气量(RV)、RV/TLC较高,一氧化碳弥散量(DLCO)较低,差异均有统计学意义(P<0. 05)。结论 FEV3/FVC检测应作为肺功能检测的常规检查,仅FEV3/FVC下降可能是早期判断轻度气道功能障碍的指标。     

第六秒用力呼气容积替代用力肺活量法筛选诊断慢性阻塞性肺疾病效果研究

目的 评估第六秒用力呼气容积(FEV6)替代用力肺活量(FVC)筛选慢性阻塞性肺疾病(COPD)的效果,确定第一秒用力呼气容积(FEV1)/FEV6诊断界值.方法 对2007年8月至2008年12月北京大学人民医院呼吸科1210例肺功能检查结果进行回顾性分析,在容量-时间曲线上测量FEV6,应用Kendall test对FEV1/FEV6与FEV1/FVC进行相关性分析;以FEV1/FVC<70%为金标准,绘制受试者工作特征曲线(ROC curve),以敏感度与特异度之和最大为标准,确定诊断界值.结果 FEV1/FEV6与FEV1/FVC高度相关(r=0.964,P<0.05).以FEV1/FVC<70%为金标准FEV1/FEV6受试者工作特征曲线下面积为0.997,面积的标准误为0.001.以敏感度和特异度之和最大确定FEV1/FEV6最佳分界点为71%,敏感度为97.7%,特异度为99.1%.结论 FEV1/FEV6与FEV1/FVC高度相关,以FEV1/FEV6<71%作为COPD诊断界值具有很高的敏感度和特异度.FEV1/FEV6可以替代FEV1/FVC用于筛选诊断COPD.     

肺功能中不同气道功能指标联合筛查用于慢性阻塞性肺疾病早期诊断价值及预后判断研究

目的:探讨FEV_1/FEV_6和FEV_3/FVC联合筛查用于慢性阻塞性肺疾病(COPD)早期诊断以及预后判断的价值研究。方法:纳入2013年2月至2016年2月,在我院接受肺功能检查的患者372例,根据患者肺功能情况将患者分为三组,A组133例患者FEV_1/FEV_6和FEV_3/FVC均正常,B组124例患者FEV_1/FEV_6和FEV_3/FVC中仅一项指标下降,C组115例患者两者均下降。观察三组患者小气道功能指标,观察FEV_3/FVC、FEV_1/FEV_6与小气道功能指标的相关性,观察FEV_3/FVC联合FEV_1/FEV_6评估早期气道阻塞的价值,随访2年,观察三组患者2年内的COPD确诊率、COPD住院率以及COPD相关死亡率。结果:A、B两组患者FVC、FEV_1、FEV_3差异均无统计学意义(P0. 05); C组患者FVC、FEV_1、FEV_3均低于A组和B组,差异有统计学意义(P0. 05); FEV_1/FEV_6和FEV_3/FVC结果从高至低排序为A组、B组和C组,差异均有统计学意义(P 0. 05);三组患者的最大呼气中期流速(MMEF)、50%肺活量最大呼气流(MEF50)/用力呼出50%肺出量的呼气流量(FEF50%)以及MEF25/FEF75%从高至低依次为A组、B组和C组,差异有统计学意义(P0. 05); Spearman相关性分析表明,FEV_1/FEV_6、FEV_3/FVC以及二者联合检测与小气道功能指标均呈明显的正相关(P0. 05); FEV_1/FEV_6和FEV_3/FVC对早期气道阻塞均具有较高的敏感度、特异度、阴性预测值和阳性预测值,尤其是两者联合进行检测时,其敏感度、特异度、阴性预测值和阳性预测值均高于二者单独检测,差异有统计学意义(P0. 05); COPD确诊率、COPD住院率以及COPD相关死亡率从高到低均为C组、B组和A组,且差异均具有统计学意义(P0. 05); FEV_3/FVC以及FEV_1/FEV_6对患者预后情况均具有较高的敏感度和特异度,两者联合检测的敏感度和特异度均显著高于单独指标检测,且其ROC曲线面积最大(P0. 05)。结论:FEV_1/FEV_6和FEV_3/FVC联合筛查对早期气道阻塞具有较高的诊断价值以及预后判断价值,可作为临床早期诊断COPD以及判断COPD患者预后的有效检测指标。     

慢性阻塞性肺疾病的影像学检查方法及进展

慢性阻塞性肺疾病（COPD）是一种进行性发展的以不完全可逆的气流受限为特征的慢性呼吸系统疾病^[1],其临床诊断主要依靠吸烟等高危因素史、临床表现及肺功能检查（PFT）等综合分析确定。PFT测量第1秒用力呼气容积（FEV1）、用力肺活量（FVC）及FEV1/FVC,以及一氧化碳弥散量（DLCO）、肺总量（TLC）、残气量（RV）等指标,反映肺的整体功能,当肺组织破坏〉30%时才会出现异常^[2],     

第6秒用力呼气量在肺功能评价中的临床意义

用力肺活量(FVC)和第1秒用力呼气量是用来诊断与鉴别诊断阻塞性和限制性通气功能障碍的两个重要指标.近几年来的研究显示第6秒用力呼气量能很好地替代FVC,不仅能减少患者呼气时间,降低因呼气延长诱发呼吸困难的风险,使患者更易配合完成合格的测定,同时还能提高气道阻塞高危因素受试者的检出率,为早期诊断和治疗提供可能.     

探讨慢性阻塞性肺疾病患者体重指数与肺功能指标的相关性

目的 研究COPD患者体重指数(BMI)与肺功能指标的相关性,为COPD患者治疗护理提供新的依据.方法 随机选取2010年1月至2011年10月来我院呼吸内科就诊的男性COPD患者115例,按BMI分成三组:低BMI组50例,正常BMI组50例,超BMI组15例,检测肺功能指标:深吸气量(IC)、第一秒用力呼气容积(FEV1)、用力肺活量(FVC)、一秒率(FEV1/FVC).结果 超BMI组IC、FEV1、FVC比正常BMI组明显增高(P＜0.05),正常BMI组IC、FEV1、FVC又比低BMI组明显增高(P＜0.05),三组FEV1/FVC无明显差异(P＞0.05).相关性分析提示BMI与IC、FEV1、FVC呈正相关,与FEV1/FVC无相关性.结论 改善COPD患者营养状况,控制理想的体重指数,可以有效地改善肺功能,提高生活质量.     

一秒钟用力呼气容积与用力肺活量之比值在慢性阻塞性肺疾病诊断分级中的价值

目的 探讨一秒钟用力呼气容积（FEV1）与用力肺活量（FVC）之比值FEV1/FVC的影响因素、变化情况以及慢性阻塞性肺疾病（COPD）诊断分级中的实际价值。方法 选择FEV1%预计值在吸入支气管扩张剂后仍低于80%，但FEV1/FVC≥70%的“可疑”COPD患者的肺功能测定数据结合历史文献进行分析、推论、求证。结果 29例“可疑”COPD患者基础肺功能情况符合我国1997年制定的COPD诊断标准，且吸入支气管扩张剂前后FEV1%预计值及FEV1/FVC无显著差异（P〉0.05），FEV1%预计值仍低于80%，FEV1/FVC则大于70%，但仍低于83%这一经典数值。结论 FEV1/FVC受年龄、呼吸肌力及肺泡伸缩程度等诸因素的影响，具有较明显的变异性，其值在70%以上时未必一定就不存在气流阻塞，它在COPD诊断分级中的价值并不象GOLD所说的那样重要，GOLD关于COPD的诊断分级标准在临床实践中的可操作性较低且容易造成混乱，建议重新修订为“使用支气管扩张剂后FEV1%预计值〈80%或FEV1/FVC仍处于减低状态可确定为不完全可逆性气流阻塞”，在对COPD轻重程度的分级时则应取消FEV1/FVC〈70%这一前提条件。     

测定慢性阻塞性肺疾病患者6s用力呼气容积的意义

目前判断气流受限的常用肺功能指标是时间肺活量,包括:第1秒用力呼气容积(FEV1)和1 s率(FEV1与用力呼气容积比值)的降低来确定的。气道阻塞患者呼气时间可明显延长,最长可达20 s或以上,但呼气时间过长会使患者出现过度通气,导致头晕、呼吸困难、肢体麻木,甚至危及性命,尤其慢性阻塞性肺疾病(COPD)患者多见于老年人,体质较差,容易出现并发症。6 s呼气容积(FEV6)是指最大吸气至肺总量位后6 s之内快速呼出气量。由于呼气时间相对较短,患者比较容易接受,不良反应少。本文就COPD患者肺功能指标用力肺活量(FVC)与FEV6及FEV1/FVC与FEV1/FEV6进行相关性分析。     

不同营养比例饮食支持治疗对COPD患者生活质量的影响

目的研究不同营养比例饮食支持治疗对COPD患者生活质量的影响。方法将60例稳定期COPD患者随机分成三组,即常规组、蛋白组、脂肪组各20例,按不同营养比例制定相应食谱,比较各组实验后16周各项研究指标的变化。结果实验后16周蛋白组与常规组、脂肪组比较：肺功能检查提示FEV1%（第一秒用力呼气容积及占预计值百分比）、FEV1/FVC%（第1秒用力呼气容积占用力肺活量的百分比）蛋白组高于常规组、脂肪组,差异有统计学意义（P〈0.05）;SF-36评分蛋白组优于常规组、脂肪组,差异有显著统计学意义（P〈0.01）;测定6 min步行距离蛋白组优于常规组、脂肪组,差异有显著统计学意义（P〈0.01）。结论摄入蛋白相对丰富的饮食为COPD患者较为理想的营养支持方式。     

FEV1/FEV6 and FEV6 as an alternative for FEV1/FVC and FVC in the spirometric detection of airway obstruction and restriction

STUDY OBJECTIVES: To evaluate the use of the FEV(1)/forced expiratory volume at 6 s of exhalation (FEV(6)) ratio and FEV(6) as an alternative for FEV(1)/FVC and FVC in the detection of airway obstruction and lung restriction, respectively. SETTING: Pulmonary function laboratory of the Academic Hospital of the Free University of Brussels. PARTICIPANTS: A total of 11,676 spirometric examinations were analyzed on subjects with the following characteristics: white race; 20 to 80 years of age; 7,010 men and 4,666 women; and able to exhale for at least 6 s. METHODS: Published reference equations were used to determine lower limits of normal (LLN) for FEV(6), FVC, FEV(1)/FEV(6), and FEV(1)/FVC. We considered a subject to have obstruction if FEV(1)/FVC was below its LLN. A restrictive spirometric pattern was defined as FVC below its LLN, in the absence of obstruction. From these data, sensitivity and specificity of FEV(1)/FEV(6) and FEV(6) were calculated. RESULTS: For the spirometric diagnosis of airway obstruction, FEV(1)/FEV(6) sensitivity was 94.0% and specificity was 93.1%; the positive predictive value (PPV) and negative predictive value (NPV) were 89.8% and 96.0%, respectively. The prevalence of obstruction in the entire study population was 39.5%. For the spirometric detection of a restrictive pattern, FEV(6) sensitivity was 83.2% and specificity was 99.6%; the PPVs and NPVs were 97.4% and 96.9%, respectively. The prevalence of a restrictive pattern was 15.7%. Similar results were obtained for male and female subjects. When diagnostic interpretation differed between the two indexes, measured values were close to the LLN. CONCLUSIONS: The FEV(1)/FEV(6) ratio can be used as a valid alternative for FEV(1)/FVC in the diagnosis of airway obstruction, especially for screening purposes in high-risk populations for COPD in primary care. In addition, FEV(6) is an acceptable surrogate for FVC in the detection of a spirometric restrictive pattern. Using FEV(6) instead of FVC has the advantage that the end of a spirometric examination is more explicitly defined and is easier to achieve.     

FEV1/FEV6 is effective as a surrogate for FEV1/FVC in the diagnosis of chronic obstructive pulmonary disease

Background and objectiveChronic Obstructive Pulmonary Disease (COPD) causes substantial morbidity and mortality across the globe. Diagnosis of COPD requires post-bronchodilator FEV1/FVC <0.70 as per GOLD Guidelines. FVC maneuver requires a minimum of 6 seconds of forceful expiration with no flow for 1 second for an accepted effort, which lacks any fixed cut-off point. This leads to discomfort, especially in advanced COPD and old aged population. We conducted this study to find the utility of FEV1/FEV6 as a surrogate for FEV1/FVC, the correlation between the two ratios, and the fixed cut-off value of FEV1/FEV6 for COPD diagnosis.MethodsThis was a prospective, cross-sectional study approved by the institutional ethics committee conducted from January 2017 to November 2018. Consented patients above 18 years suspected of COPD underwent Spirometry as per ATS guidelines. FEV1, FEV6, FEV1/FEV6 and FEV1/FVC ratios were recorded from the best acceptable maneuver.ResultsOut of 560 screened patients, 122 diagnosed as COPD. The correlation coefficient between the post-bronchodilator FEV1/FVC ratio and FEV1/FEV6 ratio was 0.972 (p < 0.01). The relationship between the post-bronchodilator FEV1/FVC ratio and FEV1/FEV6 ratio (linear regression analysis) was found out as: FEV1/FVC = ?1.845 + 1.009(FEV1/FEV6). Using this formula, the post-bronchodilator FEV1/FEV6 value of 71.845 was obtained corresponding to the post-bronchodilator FEV1/FVC value of 70.00.ConclusionWe found a positive correlation coefficient (r = 0.972, p < 0.001) between the FEV1/FEV6 and FEV1/FVC ratios and the cut off value of 71.845 (p < 0.01) for the post-bronchodilator FEV1/FEV6 ratio for the diagnosis of COPD. Thus FEV1/FEV6 should be used as a surrogate for FEV1/FVC for the diagnosis of COPD.     

Predicting inadequate spirometry technique and the use of FEV1/FEV3 as an alternative to FEV1/FVC for patients with mild cognitive impairment

Introduction and Objectives: Some patients cannot perform forced vital capacity (FVC). We conducted a study to answer three questions: Can the ability to perform components of spirometry be predicted by the Mini Mental State Examination (MMSE)? What proportion of subjects can perform forced expiratory volume in 3 s (FEV3) but not FVC? Does the forced expiratory volume in 1 s (FEV1)/FEV3 ratio concord with FEV1/FVC ratio in patients with airflow obstruction? Methods: We conducted a prospective observational study of 267 patients with a mean age of 79 years, including subjects with indicators of frailty. They performed spirometry and the MMSE. Spirometric recordings were compared to the American Thoracic Society 1994 criteria. Results: FVC was achieved by 51% of patients. Inability to perform FVC was predicted by an MMSE < 24 (specificity 94%, sensitivity of 51%). An FEV1/FEV3 ratio < 80% matched a FEV1/FVC ratio < 70% (sensitivity 96%, specificity 97%). Twenty‐five percent of subjects were able to reach FEV3 but not FVC; 14% of that group had an MMSE < 24. Subjects with an MMSE < 20 were unable reliably to perform any spirometry. Conclusion: Patients with an MMSE < 24 are usually unable to reach FVC reliably when tested on a single occasion, but some can reach FEV3. Patients with MMSE < 20 cannot do spirometry. An FEV1/FEV3 ratio < 80% can be used to help identify patients with airflow obstruction if they are unable to perform full spirometry to FVC. Please cite this paper as: Allen S, Yeung P, Janczewski M and Siddique N. Predicting inadequate spirometry technique and the use of FEV1/FEV3 as an alternative to FEV1/FVC for patients with mild cognitive impairment. The Clinical Respiratory Journal 2008; 2: 208–213.     

Obstructive and restrictive spirometric patterns: fixed cut-offs for FEV1/FEV6 and FEV6.

The purpose of this study was to determine fixed cut-off points for forced expiratory volume in one second (FEV(1))/FEV(6) and FEV(6) as an alternative for FEV(1)/forced vital capacity (FVC) and FVC in the detection of obstructive and restrictive spirometric patterns, respectively. For the study, a total of 11,676 spirometric examinations, which took place on Caucasian subjects aged between 20-80 yrs, were analysed. Receiver-operator characteristic curves were used to determine the FEV(1)/FEV(6) ratio and FEV(6) value that corresponded to the optimal combination of sensitivity and specificity, compared with the commonly used fixed cut-off term for FEV(1)/FVC and FVC. The data from the current study indicate that FEV(1)/ FEV(6) <73% and FEV(6) <82% predicted can be used as a valid alternative for the FEV(1)/FVC <70% and FVC <80% pred cut-off points for the detection of obstruction and restriction, respectively. The statistical analysis demonstrated very good, overall, agreement between the two categorisation schemes. For the spirometric diagnosis of airway obstruction (prevalence of 45.9%), FEV(1)/FEV(6) sensitivity and specificity were 94.4 and 93.3%, respectively; the positive and negative predictive values were 92.2 and 95.2%, respectively. For the spirometric detection of a restrictive pattern (prevalence of 14.9%), FEV(6) sensitivity and specificity were 95.9 and 98.6%, respectively; the positive and negative predictive values were 92.2 and 99.3%, respectively. This study demonstrates that forced expiratory volume in one second/forced expiratory volume in six seconds <73% and forced expiratory volume in six seconds <82% predicted, can be used as valid alternatives to forced expiratory volume in one second/forced vital capacity <70% and forced vital capacity <80% predicted, as fixed cut-off terms for the detection of an obstructive or restrictive spirometric pattern in adults.     

老年慢性阻塞性肺疾病患者FEV1/FVC诊断标准探讨

目的通过统计不同年龄段中老年人第1秒用力呼气容积占用力肺活量百分比（FEV1／FVC）〈70％者所占比例,对老年慢性阻塞性肺疾病（COPD）患者FEV1／FVC诊断标准进行探讨。方法2011年12月至2012年12月通过体检及问卷调查确定为无吸烟史的健康人群的508名中老年调查者,按年龄分为45—59岁组、60～69岁组和≥70岁组。所有人均进行肺通气功能检查。比较3组FEV1／FVC〈70％者所占比例是否存在统计学差异。结果3组FEV1／FVC平均值分别为80．7％,79．3％,76．5％。应用FEV1／FVC〈70％为COPD诊断标准时,3组COPD发病率分别为1．7％,2．2％,11％。应用FEV1／FVC〈65％的诊断标准时,≥70岁人群COPD的发病率都由11％降到4．7％。结论应用FEV1／FVC〈70％为诊断标准时,≥70岁无吸烟史的健康人群COPD患病率出现了难以解释的显著升高,考虑存在过度诊断,推测FEV1／FVC〈65％可能是一个更为合理的指标。     

The interpretation of the spirogram. How accurate is it for 'obstruction'?

The accuracy of the spirogram in detecting or excluding airway obstruction based on airflow limitation was assessed prospectively in 200 subjects, 74 with obstruction and 126 without it. The diagnosis of airway obstruction was based on a combination of clinical and body plethysmographic data. The ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC %) had a sensitivity of 0.82 and a specificity of 0.98. A fixed lower limit seemed better than a lower limit based on prediction formulas. Because specificity is so much higher than sensitivity, less precise clinical information is required to confirm the presence of obstruction if FEV1/FVC % is abnormal than is needed to exclude obstruction if FEV1/FVC % is normal. Using a combination of FEV1/FVC % and the ratio of forced expiratory flow (FEF) at 50% of FVC gave a higher sensitivity with a comparable specificity when compared with FEV1/FVC % used alone. A normal value for FEF between 25% and 75% of FVC virtually ruled out obstruction, but low values had poor specificity.     

The role of FEV6 in the detection of airway obstruction

OBJECTIVES: There are recent reports regarding the use of forced expiratory volume in 6 s (FEV6) in place of forced expiratory vital capacity (FVC) in the detection of airway obstruction. We aimed to investigate the role of FEV6 in comparison with FVC in the evaluation of airway obstruction. METHODS: The pulmonary function tests (PFT) results of all 5114 patients, who had been tested in the pulmonary function laboratory between 1998 and 2003, were retrospectively analyzed to investigate the relationship between FEV6 and FVC. RESULTS: We have found a mean difference of 95.35+/-121.7 (min=0, max=1050) ml (3.37%) when FVC and FEV6 values (FVC-FEV6) of all cases were compared. This difference was found to be higher (180 ml, 7.3%) in patients with airway obstruction. When FEV1/FVC is taken as the gold standard, FEV1/FEV6 had negative predictive value of 92.24% and a sensitivity of 86.09% in the detection of airway obstruction. CONCLUSIONS: Although it is easier to use FEV6 in place of FVC, relatively low sensitivity in that setting may result in the underestimation of airway obstruction. This drawback should be kept in mind when FEV6 is utilized to detect airway obstruction.     

Comparison of FEV6 and FVC for detection of airway obstruction in a community hospital pulmonary function laboratory

The National Lung Health Education Program recommends that primary care providers perform spirometry tests on cigarette smoking patients 45 years or older in order to detect airways obstruction and aid smoking cessation efforts [Ferguson GT, Enright Pl, Buist AS, et al. Office spirometry for lung health assessment in adults: a consensus statement from the national lung education program. Chest 2000; 117: 1146-61]. An abbreviated forced expiratory maneuver that requires exhalation for 6s (FEV6) has recently been proposed as a substitute for forced vital capacity (FVC) to facilitate performance of such spirometry. We set out to assess the accuracy of diagnosis of obstruction and abnormal pulmonary function using FEV6 in comparison to FVC in a community hospital population. One hundred pulmonary function tests performed at a community hospital were randomly selected and retrospectively analyzed. Sixty-three of the 100 tests had satisfactory 6-s expiration and were subject to further analysis. We compared the spirometric interpretation using Morris predictive equations for FEV1/FVC and Hankison predictive equations for FEV1/FVC and FEV1/FEV6. The Hankison set of equations is the only published reference formulas for prediction of FEV6. We found that versus our Morris gold standard, Hankison based FEV1/FVC interpretation was 100% sensitive and 67% specific for the diagnosis of obstruction and 100% sensitive and 65% specific for the diagnosis of any abnormality. The Hankison based FEV1/FEV6 interpretation was 97% sensitive and 47% specific for diagnosing obstruction and 100% sensitive and 50% specific for identifying any abnormality versus the Morris FVC based gold standard. In conclusion, in our hospital based pulmonary function laboratory, FEV6 based interpretation has excellent sensitivity for detection of spirometric abnormalities. However, its moderate specificity may hinder its utility as a screening test. Further testing is necessary to determine its reliability in different patient populations with less highly trained operators.     

The FEV1/FEV6 ratio is a good substitute for the FEV1/FVC ratio in the elderly.

AIMS: To determine the agreement between the FEV1/FEV6 ratio and the FEV1/FVC ratio in an elderly population. METHOD: The study sample consisted of 3874 participants in a cross-sectional population survey in Troms?, Norway, aged 60 years or more, in whom acceptable spirometry had been obtained. Mean differences between the FEV1/FEV6 ratio (%) and the FEV1/FVC ratio (%) were calculated according to age, sex, smoking habit, and the degree of airflow limitation. ROC-curve analysis and Kappa-statistics were used to estimate the utility of the FEV1/FEV6 ratio in predicting an FEV1/FVC ratio < 70%. RESULTS: The mean difference between FEV1/FEV6% and FEV1/FVC% was 2.7% in both men and women. The difference between the two measures increased somewhat with increasing age, and was more pronounced with smoking and decreasing FEV1/FVC ratio. The value for the FEV1/FEV6 ratio which best predicted an FEV1/FVC ratio of 70%, was 73%, and a very good agreement was found between these two cut-off values (kappa = 0.86). CONCLUSION: The FEV1/FEV6 ratio appears to be a good substitute for the FEV1/FVC ratio in an elderly population.