Table 1. The baseline characteristics of qualified studies in this meta-analysis.
| First author | Year | Region | Patients | Controls | Sample size | Gender (M/F) | Age (years) | Smoke pack-years | Fibrinogen (mg/dl) in patients | Fibrinogen (mg/dl) in controls |
|---|---|---|---|---|---|---|---|---|---|---|
| Ronnow | 2019 | Europe | COPD | Smokers | 95/95 | 49/49 | 60/59.4 | 38/30 | 356.4 ± 75.85 | 343.4 ± 53.78 |
| Ronnow | 2019 | Europe | COPD | Non-smokers | 95/95 | 49/49 | 60/58.8 | 38/0 | 356.4 ± 75.85 | 326.6 ± 65.3 |
| Olloquequi | 2019 | America | COPD | Healthy | 49/52 | 29/71 | 69.41/70.34 | 41.57/0 | 392.22 ± 106.38 | 319.81 ± 70.52 |
| Jin | 2018 | Asia | COPD | Healthy | 134/125 | 39.6/45.6 | 64.5/63.8 | 32/31.6 | 540 ± 80 | 250 ± 50 |
| Aleva | 2018 | Europe | Stable COPD | Healthy | 30/25 | 53.7/64 | 61.6/53 | 50.7/1.6 | 331.4 ± 141.9 | 305.1 ± 122.5 |
| AboEI-Magd | 2018 | Africa | AECOPD | Healthy | 45/20 | 31.1/35 | 57.71/56.65 | 39.62/31 | 567.3 ± 216.6 | 315.38 ± 68.18 |
| AboEI-Magd | 2018 | Africa | GOLD I/II | Healthy | 23/20 | 31.1/35 | 57.71/56.65 | 39.62/31 | 443.47 ± 107.98 | 315.38 ± 68.18 |
| AboEI-Magd | 2018 | Africa | GOLD III | Healthy | 13/20 | 31.1/35 | 57.71/56.65 | 39.62/31 | 595.38 ± 229.98 | 315.38 ± 68.18 |
| AboEI-Magd | 2018 | Africa | GOLD IV | Healthy | 9/20 | 31.1/35 | 57.71/56.65 | 39.62/31 | 843.33 ± 125 | 315.38 ± 68.18 |
| Zeng | 2017 | Asia | COPD | Healthy | 106/106 | 12.26/12.26 | 69.48/69.27 | NA | 429 ± 160 | 250 ± 54 |
| Ugurlu | 2017 | Asia | AECOPD | Healthy | 16/12 | NA | NA | NA | 446.44 ± 193.65 | 321.18 ± 115.24 |
| Ugurlu | 2017 | Asia | Stable COPD | Healthy | 13/12 | NA | NA | NA | 292.27 ± 74.51 | 321.18 ± 115.24 |
| Lopez-Sanchez | 2017 | Europe | Stable COPD | Healthy | 35/11 | 8.6/18.2 | 66.3/65.4 | 50/10 | 490 ± 133.3 | 310 ± 37.04 |
| Golpe | 2017 | Europe | COPD | Healthy | 20/20 | 25/25 | 70.1/NA | 62.8/NA | 387 ± 88.15 | 328 ± 40.74 |
| Diao | 2017 | Asia | Stable COPD | Smokers | 53/33 | NA | 64/58 | 38/31 | 330 ± 80 | 270 ± 70 |
| Diao | 2017 | Asia | GOLD I | Smokers | 10/33 | NA | 66/58 | 39/31 | 310 ± 54 | 270 ± 70 |
| Diao | 2017 | Asia | GOLD II | Smokers | 15/33 | NA | 63/58 | 38/31 | 330 ± 100 | 270 ± 70 |
| Diao | 2017 | Asia | GOLD III | Smokers | 19/33 | NA | 64/58 | 38/31 | 350 ± 66 | 270 ± 70 |
| Diao | 2017 | Asia | GOLD IV | Smokers | 9/33 | NA | 62/58 | 39/31 | 360 ± 100 | 270 ± 70 |
| Arellano-Orden | 2017 | Europe | COPD | Smokers | 96/33 | 0/0 | 67/58 | 71.9/46.9 | 520.5 ± 126.4 | 595 ± 133.3 |
| Zhang | 2016 | Asia | Stable COPD | Healthy | 43/43 | 20.9/23.3 | 62.3/60.8 | 47.3/43.9 | 297 ± 34.3 | 271 ± 66.8 |
| Zhang | 2016 | Asia | AECOPD | Healthy | 43/43 | 20.9/23.3 | 62.3/60.8 | 47.3/43.9 | 352 ± 81.3 | 271 ± 66.8 |
| Golpe | 2016 | Europe | COPD | Smokers | 67/67 | 22.4/22.4 | 59.4/58.2 | 52.7/43.7 | 378.4 ± 69.6 | 352.2 ± 45.6 |
| Akiki | 2016 | Asia | COPD | Healthy | 90/180 | 42.2/63.5 | 62/55 | NA | 299.2 ± 104.8 | 313.5 ± 64.2 |
| Tudorache | 2015 | Europe | Stable COPD | Healthy | 22/20 | NA | 63/63 | NA | 303 ± 70 | 262 ± 40 |
| Tudorache | 2015 | Europe | AECOPD | Healthy | 19/20 | NA | 63/63 | NA | 584 ± 62 | 262 ± 40 |
| Stoll | 2015 | Europe | COPD | Smokers | 54/21 | 38.9/38.1 | 59/61 | 38/39 | 420 ± 105 | 360 ± 72.5 |
| Stoll | 2015 | Europe | COPD | Non-smokers | 54/21 | 38.9/42.9 | 59/63 | 38/0 | 420 ± 105 | 300 ± 60 |
| Mutlu | 2015 | Asia | Stable COPD | Healthy | 29/29 | 16/10 | 68/64 | NA | 366 ± 128 | 345 ± 174 |
| Mutlu | 2015 | Asia | AECOPD | Healthy | 29/29 | 16/10 | 65/64 | NA | 487 ± 245 | 345 ± 174 |
| Ishikawa | 2015 | Asia | COPD | Smokers | 47/30 | 4.3/6.7 | 70.8/62.7 | 62.3/57.3 | 300 ± 100 | 303.5 ± 101.2 |
| Ishikawa | 2015 | Asia | COPD | Non-smokers | 47/20 | 4.3/50 | 70.8/59 | 62.3/0.34 | 300 ± 100 | 289 ± 96.3 |
| Gumus | 2015 | Asia | AECOPD | Healthy | 43/30 | 7/17 | 68/64 | 53/40 | 581.4 ± 353.7 | 237.8 ± 207.4 |
| Boyuk | 2015 | Asia | COPD | Non-smokers | 43/38 | 44.2/NA | NA | NA | 363.53 ± 93.36 | 356 ± 50.33 |
| Boyuk | 2015 | Asia | GOLD I | Non-smokers | 9/38 | NA | 57.67/NA | NA | 361.89 ± 72.63 | 356 ± 50.33 |
| Boyuk | 2015 | Asia | GOLD II | Non-smokers | 21/38 | NA | 65.14/NA | NA | 371.1 ± 92.41 | 356 ± 50.33 |
| Boyuk | 2015 | Asia | GOLD III | Non-smokers | 13/38 | NA | 60.23/NA | NA | 352.46 ± 111.91 | 356 ± 50.33 |
| Pizarro | 2014 | Europe | COPD | Smokers | 62/17 | 6/29 | 62/59 | 60/41 | 400 ± 96.3 | 390 ± 66.7 |
| Pizarro | 2014 | Europe | COPD | Non-smokers | 62/18 | 6/61 | 62/58 | 60/0 | 400 ± 96.3 | 330 ± 74.1 |
| Gagnon | 2014 | America | GOLD I | Healthy | 37/19 | 32/31 | 65/62 | 44/36 | 234 ± 63 | 345 ± 249 |
| Can | 2014 | Asia | Stable COPD | Healthy | 46/41 | 13/26.8 | 55.92/52.41 | 39.63/5.56 | 406.77 ± 172.6 | 336.53 ± 96.1 |
| Can | 2014 | Asia | GOLD II | Healthy | 17/41 | 13/26.8 | 55.92/52.41 | 39.63/5.56 | 354.06 ± 170.5 | 336.53 ± 96.1 |
| Can | 2014 | Asia | GOLD III | Healthy | 15/41 | 13/26.8 | 55.92/52.41 | 39.63/5.56 | 397.55 ± 162.1 | 336.53 ± 96.1 |
| Can | 2014 | Asia | GOLD IV | Healthy | 14/41 | 13/26.8 | 55.92/52.41 | 39.63/5.56 | 480.81 ± 192.7 | 336.53 ± 96.1 |
| Wang | 2013 | Asia | Stable COPD | Healthy | 70/70 | 14.3/18.6 | 69/68 | 56.4/54.3 | 417.7 ± 91.4 | 366.7 ± 101.4 |
| Wang | 2013 | Asia | AECOPD | Healthy | 70/70 | 14.3/18.6 | 69/68 | 56.4/54.3 | 466.1 ± 90.3 | 366.7 ± 101.4 |
| Lazzeri | 2013 | Europe | COPD | Healthy | 71/747 | 33.8/26.8 | 74/67 | 54/46.1 | 434 ± 148.9 | 391 ± 98.5 |
| Waschki | 2012 | Europe | COPD | Smokers | 127/22 | 39.20/45.5 | 64.6/68 | 38.3/27.2 | 504 ± 122 | 455 ± 129 |
| Waschki | 2012 | Europe | COPD | Non-smokers | 127/22 | 39.20/68.2 | 64.6/66.4 | 38.3/0 | 504 ± 122 | 408 ± 57 |
| Lazovic | 2012 | Europe | COPD | Healthy | 43/40 | 39.50/47.5 | 61.8/45.45 | 28.2/5.94 | 603 ± 229 | 414 ± 163 |
| Gopal | 2012 | Europe | Stable COPD | Healthy | 146/81 | 45.90/44.4 | 59.56/58.78 | 36.37/35.41 | 351.8 ± 84.5 | 330 ± 30 |
| Cockayne | 2012 | America | GOLD I/II | Smokers | 75/15 | 28/27 | 66.9/66.8 | 51.9/42.9 | 430 ± 74.1 | 460 ± 37 |
| Cockayne | 2012 | America | GOLD III/IV | Non-smokers | 65/30 | 25/30 | 66.3/66.4 | 58.8/0.5 | 460 ± 81.5 | 370 ± 59.3 |
| Agusti | 2012 | Europe | COPD | Smokers | 1755/297 | 34/45 | 63.5/55.5 | 48.9/31.7 | 448 ± 95.6 | 391 ± 65.2 |
| Agusti | 2012 | Europe | COPD | Non-smokers | 1755/202 | 34/62 | 63.5/53 | 48.9/0.2 | 448 ± 95.6 | 369 ± 78.5 |
| Valvi | 2012 | America | GOLD I | Healthy | 2669/7271 | NA | NA | NA | 309.5 ± 67.16 | 294.6 ± 59.69 |
| Valvi | 2012 | America | GOLD II | Healthy | 2221/7271 | NA | NA | NA | 320.7 ± 70.69 | 294.6 ± 59.69 |
| Valvi | 2012 | America | GOLD III/IV | Healthy | 585/7271 | NA | NA | NA | 336.8 ± 74.98 | 294.6 ± 59.69 |
| Dickens | 2011 | Europe | COPD | Smokers | 201/37 | 27/32 | 64.5/60.7 | 45.7/29.3 | 466 ± 117.5 | 425 ± 100 |
| Dickens | 2011 | Europe | COPD | Non-smokers | 201/37 | 27/62 | 64.5/60 | 45.7/0 | 466 ± 117.5 | 387 ± 83 |
| Dickens | 2011 | Europe | Stable COPD | Smokers | 157/37 | NA | NA | NA | 464 ± 115 | 425 ± 100 |
| Dickens | 2011 | Europe | AECOPD | Non-smokers | 33/37 | NA | NA | NA | 534 ± 156 | 387 ± 83 |
| Selcuk | 2010 | Asia | COPD | Healthy | 85/39 | 40/41 | 58.4/57.8 | 28/22 | 332 ± 129 | 295 ± 73 |
| Garcia-Rio | 2010 | Europe | COPD | Healthy | 324/110 | 26/54 | 64/55 | 40/10 | 347.8 ± 97.5 | 312.3 ± 71.8 |
| Garcia-Rio | 2010 | Europe | GOLD I | Healthy | 177/110 | 32.2/54 | 62/55 | 30/10 | 346 ± 104 | 312.3 ± 71.8 |
| Garcia-Rio | 2010 | Europe | GOLD II | Healthy | 128/110 | 18/54 | 67/55 | 45/10 | 363 ± 111 | 312.3 ± 71.8 |
| Garcia-Rio | 2010 | Europe | GOLD III | Healthy | 19/110 | 15.8/54 | 70/55 | 40/10 | 373 ± 117 | 312.3 ± 71.8 |
| Yanbaeva | 2009 | Europe | COPD | Healthy | 355/195 | 38/52 | 64.2/54.3 | 39.9/29.6 | 360 ± 43.7 | 330 ± 44.4 |
| Watz | 2009 | Europe | GOLD I | Healthy | 34/30 | 26/23 | 66.3/62.6 | 46.9/53.2 | 395 ± 64 | 410 ± 81 |
| Watz | 2009 | Europe | GOLD II | Healthy | 57/30 | 28/23 | 63.3/62.6 | 50.7/53.2 | 431 ± 98 | 410 ± 81 |
| Watz | 2009 | Europe | GOLD III | Healthy | 43/30 | 19/23 | 63.3/62.6 | 55.6/53.2 | 468 ± 115 | 410 ± 81 |
| Watz | 2009 | Europe | GOLD IV | Healthy | 36/30 | 25/23 | 63.7/62.6 | 54/53.2 | 444 ± 89 | 410 ± 81 |
| Undas | 2009 | Europe | Stable COPD | Healthy | 56/56 | 8.9/14.3 | 64.9/63.8 | NA | 408 ± 160 | 271 ± 57 |
| Valipour | 2008 | Europe | Stable COPD | Healthy | 30/30 | 30/30 | 60/59 | 58/27 | 424 ± 74.8 | 360 ± 49.6 |
| Valipour | 2008 | Europe | AECOPD | Healthy | 30/30 | 23/30 | 62/59 | 57/27 | 419 ± 104.4 | 360 ± 49.6 |
| Polatli | 2008 | Asia | Stable COPD | Healthy | 33/16 | NA | 63.42/59.63 | 33.64/21.56 | 346.88 ± 92.3 | 289.99 ± 39.9 |
| Polatli | 2008 | Asia | AECOPD | Healthy | 26/16 | NA | 68/59.63 | 45.04/21.56 | 447.67 ± 128 | 289.99 ± 39.9 |
| Kunter | 2008 | Asia | AECOPD | Non-smokers | 30/10 | 13.3/NA | 72.37/64.5 | NA | 623.77 ± 189.45 | 305.7 ± 77.73 |
| Higashimoto | 2008 | Asia | COPD | Healthy | 111/75 | 2.7/2.7 | 74.9/64.5 | 61/41.2 | 340 ± 126.4 | 322 ± 103.9 |
| Eickhoff | 2008 | Europe | COPD | Smokers | 60/20 | 45/60 | 62/59 | 66/39 | 426 ± 87.4 | 367 ± 51.1 |
| Eickhoff | 2008 | Europe | COPD | Non-smokers | 60/20 | 45/65 | 62/62 | 66/0 | 426 ± 87.4 | 382 ± 82.2 |
| Dentener | 2008 | Europe | COPD | Healthy | 16/25 | 37.5/52 | 62/56 | 28/15 | 244 ± 56 | 182 ± 30 |
| Mannino | 2003 | America | GOLD I | Healthy | 1260/8446 | NA | NA | NA | 292 ± 51 | 281 ± 47 |
| Mannino | 2003 | America | GOLD II | Healthy | 878/8446 | NA | NA | NA | 316 ± 58 | 281 ± 47 |
| Mannino | 2003 | America | GOLD III/IV | Healthy | 228/8446 | NA | NA | NA | 340 ± 67 | 281 ± 47 |
| Ferroni | 1997 | Europe | COPD | Healthy | 33/16 | 9/18.8 | 68/58 | NA | 342 ± 61 | 233 ± 44 |
Data are expressed as cases/controls. Abbreviations: AECOPD, acute exacerbations of COPD; M/F, male/female; NA, not available.