Table 3 Description of studies assessing the properties of C-Reactive Protein (CRP) for identifying bacterial vs non-bacterial AECOPD
Author (reference) | Setting | Antibiotics or Steroids in the exclusion criteria (length of exclusion) | GOLD Stage of Cohort | Definition of bacterial cause of exacerbation | Number of exacerbations | Number of exacerbations with bacterial cause | Mean CRP (SD; mg/L) Bacterial exacerbation | Mean CRP (SD; mg/L) Non-bacterial exacerbation |
|---|---|---|---|---|---|---|---|---|
Abedini [24] | H | Neither | I–IV | Positive sputum culture | 68 | 26 | – | – |
Andelid [45] | OP | Neither | I–IV | Positive sputum culture | 29 | 14 | – | – |
Bafadhel [39] | OP | Antibiotics & Steroids | I–IV | Positive sputum culture OR total aerobic count > 107 CFU | 158 | 84 | 13 (41)* | 5 (15)* |
Bathoorn [40] | OP | Steroids | – | High semi-quantitative growth density of PPM on sputum culture | 37 | 8 | 9.08 (4.56–26.2)* | 2.6 (1.4–15.3)* |
Bircan [25] | H | Antibiotics (1 week) & Steroids (2 weeks) | - | Purulent sputum | 51 | – | – | – |
Chang [14] | H | Neither | I–IV | Positive sputum culture | 72 | 30 | – | – |
Clark [15] | H | Neither | – | Positive sputum culture | 195 | 66 | 20 (3–39)* | 8 (3–28)* |
Daniels [27] | H | Antibiotics & Steroids | I–IV | Positive sputum culture | 243 | 142 | 33.0 (9.75–88.25)* | 17.0 (5–61.0)* |
Dev [17] | H | Antibiotics | – | Positive sputum culture | 50 | 29 | 103 (98) | 92 (90) |
Ergan [11] | ICU | Neither | III–IV | Sputum sample > 106 CFU OR endotracheal/tracheal aspirate > 105 CFU OR mini-bronchoalveolar lavage > 104 CFU | 52 | 16 | 73 (40–87)* | 53 (21–104)* |
Gallego [41] | OP | Antibiotics & Steroids | I–IV | Positive sputum culture | 265 | 167 | 58.3 (21.0–128.2)* | Viral = 37.3 (18.6–79.1)* Non-pathogenic = 36.4 (10.8–93.7)* |
Hassan [19] | H | Antibiotics (2 weeks) & Steroids (2 weeks) | I–IV | Combination of clinical observations, sputum culture, X-ray images & lab results | 30 | 22 | 22.27 (0.968–1)+ | – |
Kawamatawong [29] | H | Neither | II–IV | Positive sputum culture for aerobic organisms | 62 | 29 | 41.62 (4.16–274.8)* | Viral = 37.46 (23.69–700.0)* Non-pathogenic = 15.56 (1.0–238.5)* |
Lacoma [30] | H | Neither | – | Positive sputum culture | 161 | 76 | 88.61 (34.89–201.12)* | 88.66 (38.04–164.35)* |
Li [31] | H | Antibiotics (4 weeks) | – | Positive sputum culture | 164 | 98 | 73.81 (18.27) | 7.91 (3.01) |
Lozo Vukovac [20] | H | Antibiotics (2 months) & Steroids (2 months) | II–IV | Bronchoalveolar aspirate > 103 CFU/mL | 84 | 60 | 29.4 (11.2) | 16.8 (11.6) |
Morsi [32] | H | Neither | – | Positive sputum culture | 31 | 19 | – | – |
Nseir [12] | ICU | Neither | II–IV | Endotracheal aspirate > 106 CFU/mL | 98 | 40 | 56 (92) | 56 (65) |
Peng [21] | H | Antibiotics & Steroids | - |  ≥ 1 PPMs in excess (≥ 1 log) of normal microbiological flora in sputum OR PPMs reaching a level of absolute growth > 106 CFU/mL (Strep. pneumoniae > 105 CFU/mL sufficient) | 81 | 55 | – | – |
Qian [38] | H & OP | Antibiotics & Steroids | - | Positive sputum culture | 150 | 82 | – | – |
Scherr [22] | H | Neither | I–IV | Positive sputum culture | 108 | 65 | 45.7 (52.6) | 46.4 (63.2) |
Sethi [46] | OP | – | I–IV | Positive sputum culture | 150 | 84 | – | – |
Stockley [42] | OP | Antibiotics (4 weeks) | – | Positive sputum culture | 121 | 86 | – | – |
Tanriverdi [13] | ICU | Neither | – | Positive sputum culture > 105 CFU/mL | 77 | 28 | 106.7 (83.7) | 105.6 (101.5) |
Vaitkus [23] | H | Antibiotics (1 month) & Steroids (1 month) | – | Positive sputum culture > 106 CFU/mL | 40 | 18 | 23.5 (20.8) | 5.8 (2.5) |
Van de Geijn [37] | H | Antibiotics (2 weeks) & Steroids (2 weeks) | I–IV | Combination of clinical observations, sputum culture, X-ray images & lab results | 45 | 22 | 114.95 (118.93) | 21.17 (27.20) |
Xiong [35] | H | Antibiotics (2 weeks) & Steroids (2 weeks) | I–IV | Positive sputum culture | 78 | 38 | 56.65 (31.65) | 19.62 (8.78) |
Xu [36] | H | Antibiotics (4 weeks) | – | Positive sputum culture > 107 CFU/mL | 60 | 26 | 58.87 (9.77) | 18.66 (3.98) |