Table 1 Basic characteristics of the studies included in the meta-analysis
Author | Year | Country | Language | Research type | Cases (FE-CB/NE) | Gender (male) (FE-CB/NE) | Age (years) (FE-CB/NE) | Evaluation indices |
|---|---|---|---|---|---|---|---|---|
Alcázar-Navarrete, B. | 2016 | Spain | English | Cross-sectional observation study | 34/34 | 32/29 | 72 ± 10.471 ± 9.9 | FEV1%, FEV1/FVC, FVC%, BMI, the quantity of cigarettes smoked (pack-years), CAT score |
Arkhipov, V. | 2017 | Russia | English | Cross-sectional observation study | 415/398 | 356/347 | 64.6 ± 8.564.7 ± 8.9 | FEV1%, the quantity of cigarettes smoked (pack-years), BMI, CAT score |
Calle Rubio, M. | 2017 | Spain | English | Cross-sectional observation study | 188/307 | 157/255 | 69.5 ± 8.667.2 ± 9.3 | FEV1, FEV1%, the quantity of cigarettes smoked (pack-years), CAT, mMRC, BODEx, exacerbations in previous year, BMI |
Chee-Shee Chai | 2019 | Malaysia | English | Cross-sectional observation study | 75/54 | 70/50 | 70.7 ± 9.274.1 ± 8.1 | FEV1%, the quantity of cigarettes smoked (pack-years), CAT, mMRC, exacerbations in previous year |
Corlateanu, A. | 2017 | Moldova | English | Cross-sectional observation study | 138/175 | – | FVC%, FEV1%, FEV1/FVC, CAT | |
Cosio, B. G. | 2016 | Spain | English | Cross-sectional observation study | 99/550 | 85/460 | 69.5 ± 8.167.4 ± 9.1 | FEV1%, FVC%, FEV1/FVC, the quantity of cigarettes smoked (pack-years), BMI, CAT, Charlson comorbidity index |
Golpe, R. | 2018 | Spain | English | Cross-sectional observation study | 194/531 | 167/433 | 72.7 ± 8.968.5 ± 9.5 | FEV1%, FVC%, FEV1/FVC, BMI, BODEx, Charlson comorbidity index |
Koblizek, V. | 2017 | Czech | English | Cross-sectional observation study | 687/2125 | 494/1500 | 66.6 ± 8.366.3 ± 8.7 | FEV1%, FVC%, BMI, CAT, mMRC, exacerbations in previous year |
Miravitlles, M. | 2015 | Germany | English | Cross-sectional observation study | 602/1894 | 514/1617 | 69.3 ± 9.266.6 ± 9.7 | FEV1%, FVC%, FEV1, FVC, FEV1/FVC, mMRC, exacerbations in previous year, BODEx, CAT, BMI, the quantity of cigarettes smoked (pack-years), Charlson comorbidity index |
Pan Qing | 2016 | China | Chinese | Cross-sectional observation study | 267/82 | 217/68 | 76 ± 10.061 ± 6.4 | FEV1、FEV1% |