General population studies comparing the diagnostic criteria of forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.70 and FEV1/FVC < lower limit of normal (LLN)
| Study | Country | Subjects (% male#) | Age group years | Nonsmoker | FEV1/FVC <0.70 | FEV1/FVC <LLN | Comment | ||
| Male | Female | Male | Female | ||||||
| Present study | Finland | 1323 (45.0) | 21–74 | 43.2 | 9.4 | 3.3 | 6.0 | 2.6 | LLN fifth percentile GLI2012 [10]. Age-dependent increase in difference between fixed limit and LLN from 0.3% (40–49 years) to 10.6% (70–74 years). |
| Celli et al., 2003 [11] | USA | 9838 (47.8) | 30–80 | 43.8 | 19.9 | 13.8 | 15.0 | 13.5 | LLN fifth percentile NHANES [12]. Age-dependent increase in difference between fixed limit and LLN from −2.1% (40–44 years) to 28.8% in (70–74 years). |
| Hansen et al., 2007 [4] | USA | 9403¶ (42.9) | 20–80 | 62.6¶ | 12.5¶ | 8.2¶ | 11.4¶ | 9.4¶ | LLN fifth percentile NHANES [12]. Age-dependent increase in difference between fixed limit and LLN from −3.1% and −4.4% (40–49 years) to 19.9% and 12.1% (>80 years) in men and women, respectively. |
| Vanfleteren et al., 2012 [13] | The Netherlands | 592 (50.7) | 40– ≥70 | 34.4 | 28.5 | 19.5 | 19.7 | 17.8 | LLN fifth percentile NHANES [12]. |
| Scholes et al., 2014 [14] | England and Wales | 7879 (42.3) | 40–95 | 52.5 | 26.3 | 18.6 | 15.0 | 11.3 | LLN fifth percentile GLI2012 [10]. The gap in prevalence between GOLD and LLN increased in older age groups. Sex differences in the risk of obstruction were significantly higher in men using GOLD compared with no significant difference using LLN. |
| Hnizdo et al., 2006 [15] | USA | 13 842 | 20–80 | NA | 21.1 | 18.5 | LLN fifth percentile NHANES [12]. Fixed-limit criterion underestimates airflow obstruction by 29% in 20–49-year-olds and overestimates it by 58% in 50–80-year-olds when compared with FEV1/FVC <LLN and FEV1 <100% predicted. | ||
| Mannino et al., 2007 [16] | USA | 4965 (43.4) | ≥65 | 45.9 | 42.1 | 19.3 | LLN fifth percentile NHANES [12]. Follow-up of 11 years found subjects with FEV1/FVC <0.70 but >LLN to have increased mortality and COPD-related hospitalisations. | ||
| Perez-Padilla et al., 2007 [17] | Latin America | 5183 | ≥40 | NA | 21.7 | 11.7 | Evaluated data with LLN fifth percentile NHANES [12] and reference values derived from the same study. Data evaluated in groups of high and low risk of COPD based on smoking exposure. Age-dependent increase in prevalence in both groups. | ||
| Shirtcliffe et al., 2007 [18] | New Zealand | 749 (54.2) | 25– ≥70 | 46.2 | 14.2 | 9.0 | LLN calculated from a concurrent study sample of healthy nonsmokers. Age-adjusted prevalences shown. | ||
| Roche et al., 2008+ [19] | France | 4764 (48.0) | 45– ≥75 | 48.2 | 8.7 | 6.4 | LLN fifth percentile European Coalition for Steel and Coal [20]. | ||
| Swanney et al., 2008 [7] | The Netherlands | 4557 Dutch | 17– ≥90 | NA | 20.5 | 12.3 | LLN from Dutch reference values from that substudy, for UK data LLN of Falaschetti et al. [21] and for USA the fifth percentile LLN of NHANES [12]. GOLD guidelines caused false-positive rates of up to 60% when applied to entire populations. | ||
| UK | 24 604 UK | 13.4 | 14.1 | ||||||
| USA | 6829 USA | 21.8 | 15.5 | ||||||
| Vaz Fragoso et al., 2010 [22] | USA | 3502 (47.8) | 40–80 | 40.8 | 27.0 | 13.8 | LLN based on LMS method LLN fifth percentile from study sample [23]. | ||
| Garcia-Rio et al., 2011 [24] | Spain | 3802§ | 40–80 | 27.6§ | 10.2 | 5.5 | LLN based on Roca et al. [25]. A subsample of 885 subjects (58.2% male) was further evaluated with subjects diagnosed with GOLD but normal with LLN presenting worse self-reported quality of life, but similar exercise, frequency of exacerbations and indices of systemic effects. | ||
| Lamprecht et al., 2011 [26] | Austria | 1258 (54.5) | ≥40 | 43.1 | 24.2 | 15.3 | LLN fifth percentile NHANES [12]. Discordance increased with age. Discordant cases more often older, male and never-smokers, and had fewer respiratory symptoms and better FEV1. Discordant cases had heart disease significantly more often. | ||
| Waked et al., 2011 [27] | Lebanon | 2201 (48.4) | ≥40 | 33.3 | 9.7 | 12.5 | LLN based on LMS method fifth percentile from study sample [23]. The number of never-smokers was small and the LLN-based definition showed a parabolic prevalence estimation by age. | ||
| Danielsson et al., 2012 [28] | Sweden | 548 (48.2) | ≥40 | 42.7 | 15.7 | 9.3 | LLN fifth percentile NHANES [12]. | ||
| van Dijk et al., 2015 [29] | Canada | 4882 (43.0) | 40– ≥80 | 43.0 | 17.0 | 11.2 | LLN fifth percentile NHANES [12]. Evaluated the clinical significance of fixed-ratio- versus LLN-based criteria. Fixed ratio alone may lead to misdiagnosis. FEV1/FVC <LLN and a low FEV1 is strongly associated with clinical outcomes. Guidelines should be reconsidered to require both spirometric abnormalities to reduce overdiagnosis of COPD. | ||
| Turkeshi et al., 2015 [30] | Belgium | 411 (37.0) | ≥80 | 69.6 | 27.0 | 9.2 | LLN fifth percentile GLI2012 [10]. Only airflow limitation by GLI2012 was independently associated with mortality. Subjects with FEV1/FVC <0.70 but above GLI2012 LLN had no significantly higher risk of mortality or hospitalisation. | ||
Data are presented as n or %, unless otherwise stated. GLI2012: Global Lung Function Initiative reference values; NHANES: National Health and Nutrition Examination Survey; GOLD: Global Initiative for Chronic Obstructive Lung Disease; COPD: chronic obstructive pulmonary disease; NA: not available. #: where available; ¶: includes only never-smokers and current smokers from the population sample; +: primary care sample of routine preventive visits; §: full sample, study analysis of health-related quality of life pertaining to a smaller subsample of subjects with no COPD.