Table 4. GRADE evidence profile.
| Quality assessment | Summary of findings | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Number of patients | Effect | ||||||||||
| No. of studies | Study design | Risk of bias | Inconsistency | Indirectness | Imprecision | Publication bias | Bronchiectasis | No bronchiectasis | Relative (95%CI) | Absolute (95%CI) | Quality |
| Tuberculosis history | |||||||||||
| 6 | Observational study | not serious | seriousa | not serious | seriouso | not found | 176/573 | 103/827 | RR 2.49 (1.65 to 3.75) | 96 per 1000 | ⊕○○○ |
| Smoking history | |||||||||||
| 5 | Observational study | not serious | not serious | not serious | not serious | not found | 367/530 | 393/737 | RR 1.25 (1.15 to 1.35) | 635 per 1000 | ⊕⊕○○ |
| Pseudomonas aeruginosa infection | |||||||||||
| 7 | Observational study | not serious | not serious | not serious | seriouso | not found | 107/605 | 35/874 | RR 4.36 (3.04 to 6.27) | 28 per 1000 | ⊕○○○ |
| Purulent sputum | |||||||||||
| 4 | Observational study | not serious | seriousb | not serious | seriouso | not found | 83/229 | 35/285 | RR 3.09 (1.68 to 5.69) | 70 per 1000 | ⊕○○○ |
| Purulent mucus sputum | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | serious o | not found | 57/119 | 17/150 | RR 4.18 (2.57 to 6.79) | 122 per 1000 | ⊕○○○ |
| Positive sputum culture | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso | not found | 51/119 | 41/150 | RR 1.56 (1.11 to 2.17) | 284 per 1000 | ⊕○○○ |
| Admission within the past year | |||||||||||
| 3 | Observational study | not serious | not serious | not serious | seriouso | not found | 110/162 | 85/240 | RR 1.82 (1.51 to 2.20) | 222 per 1000 | ⊕○○○ |
| Daily dyspnea | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso | not found | 101/119 | 54/150 | RR 2.40 (1.91 to 3.01) | 294 per 1000 | ⊕○○○ |
| Hypertension history | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 76/192 | 113/313 | RR 1.10 (0.87 to 1.38) | 362 per 1000 | ⊕○○○ |
| Diabetes history | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 40/192 | 50/313 | RR 1.32 (0.92 to 1.90) | 208 per 1000 | ⊕○○○ |
| Female | |||||||||||
| 8 | Observational study | not serious | seriousc | not serious | serious p | not found | 259/692 | 374/977 | RR 1.09 (0.91 to 1.31) | 328 per 1000 | ⊕○○○ |
| Mucous sputum | |||||||||||
| 3 | Observational study | not serious | seriousd | not serious | seriouso,p | not found | 69/172 | 156/189 | RR 0.29 (0.05 to 1.66) | 546 per 1000 | ⊕○○○ |
| Klebsiella pneumoniae infection | |||||||||||
| 6 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 47/552 | 78/835 | RR 0.92 (0.66 to 1.30) | 49 per 1000 | ⊕○○○ |
| Escherichia coli infection | |||||||||||
| 4 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 19/476 | 15/709 | RR 1.92 (0.99 to 3.75) | 21 per 1000 | ⊕○○○ |
| Streptococcus pneumoniae infection | |||||||||||
| 4 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 7/452 | 11/649 | RR 0.84 (0.35 to 2.05) | 10 per 1000 | ⊕○○○ |
| Acinetobacter baumannii infection | |||||||||||
| 3 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 12/376 | 24/589 | RR 0.79 (0.40 to 1.55) | 41 per 1000 | ⊕○○○ |
| Stenotrophomonas maltophilia infection | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 0/129 | 6/204 | RR 0.23 (0.03 to 1.86) | 30 per 1000 | ⊕○○○ |
| Enterobacter cloacae infection | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 8/333 | 9/499 | RR 1.33 (0.52 to 3.42) | 18 per 1000 | ⊕○○○ |
| Haemophilus infection | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 6/76 | 5/126 | RR 1.42 (0.50 to 3.98) | 69 per 1000 | ⊕○○○ |
| Anticholinergic therapy | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriouso,p | not found | 107/140 | 96/142 | RR 1.11 (0.96 to 1.28) | 713 per 1000 | ⊕○○○ |
| FEV1/FVC | |||||||||||
| 6 | Observational study | not serious | seriouse | not serious | not serious | not found | 548 | 778 | - | SMD-0.61 (-0.89 to -0.32) | ⊕○○○ |
| FEV1% | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriousq | not found | 119 | 150 | - | SMD-0.96 (-1.22 to -0.71) | ⊕○○○ |
| FEV1%pred | |||||||||||
| 4 | Observational study | not serious | not serious | not serious | not serious | not found | 463 | 692 | - | SMD-0.38 (-0.50 to -0.26) | ⊕⊕○○ |
| PaO2 | |||||||||||
| 3 | Observational study | not serious | not serious | not serious | not serious | not found | 390 | 595 | - | SMD-0.14 (-0.27 to -0.01) | ⊕⊕○○ |
| Hospital stay | |||||||||||
| 3 | Observational study | not serious | not serious | not serious | not serious | not found | 298 | 468 | - | SMD 0.41 (0.26 to 0.56) | ⊕⊕○○ |
| Duration of symptoms | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriousq | not found | 110 | 135 | - | SMD 0.31 (0.05 to 0.57) | ⊕○○○ |
| CRP | |||||||||||
| 4 | Observational study | not serious | serious f | not serious | not serious | not found | 385 | 571 | - | SMD 0.50 (0.07 to 0.93) | ⊕○○○ |
| WBC | |||||||||||
| 4 | Observational study | not serious | seriousg | not serious | not serious | not found | 433 | 685 | - | SMD 0.72 (0.07 to 1.36) | ⊕○○○ |
| N% | |||||||||||
| 3 | Observational study | not serious | serioush | not serious | not serious | not found | 816 | 1116 | - | SMD 0.91 (0.09 to 1.72) | ⊕○○○ |
| Smoking index (pack/year) | |||||||||||
| 5 | Observational study | not serious | seriousi | not serious | not serious | not found | 302 | 382 | - | SMD 0.72 (-0.07 to 1.50) | ⊕○○○ |
| BMI | |||||||||||
| 3 | Observational study | not serious | serious j | not serious | not serious | not found | 420 | 602 | - | SMD -0.13 (-0.37 to 0.11) | ⊕○○○ |
| Age | |||||||||||
| 8 | Observational study | not serious | seriousk | not serious | not serious | not found | 692 | 977 | - | SMD 0.15 (-0.10 to 0.39) | ⊕○○○ |
| PaCO2 | |||||||||||
| 3 | Observational study | not serious | seriousl | not serious | not serious | not found | 390 | 595 | - | SMD 0.31 (-0.01 to 0.64) | ⊕○○○ |
| ESR | |||||||||||
| 3 | Observational study | not serious | seriousm | not serious | not serious | not found | 390 | 595 | - | SMD 0.53 (-0.65 to 1.72) | ⊕○○○ |
| Hb | |||||||||||
| 3 | Observational study | not serious | not serious | not serious | not serious | not found | 390 | 595 | - | SMD -0.12 (-0.25 to 0.00) | ⊕⊕○○ |
| FIB | |||||||||||
| 4 | Observational study | not serious | seriousn | not serious | not serious | not found | 463 | 692 | - | SMD 0.78 (-0.01 to 1.58) | ⊕○○○ |
| Albumin | |||||||||||
| 2 | Observational study | not serious | not serious | not serious | seriousq | not found | 130 | 193 | - | SMD -0.05 (-0.27 to 0.18) | ⊕○○○ |
BMI, body mass index; CI, credible interval; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; FEV1/FVC, the ratio between forced expiratory volume in 1s and forced vital capacity; FEV1%, the percentage of FEV1;. FEV1%pred, FEV1 as a percentage of the predicted value; FIB, plasma fibrinogen; GRADE, grading of recommendations assessment, development, and evaluation; Hb, hemoglobin; N%, percentage of neutrophils; PaCO2, arterial carbon dioxide partial pressure; PaO2, arterial oxygen pressure; RR, risk ratio; SMD, standardized mean difference; WBC, leukocytes.
GRADE Working Group grades of evidence High quality(⊕⊕⊕⊕): Further research is unlikely to change our confidence in the estimate of effect. Moderate quality(⊕⊕⊕○): Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality(⊕⊕○○): Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality(⊕○○○): We are very uncertain about the estimate.
a. I2=61.7%; b. I2=64.1%; c. I2=59.0%; d. I2=90.9%; e. I2=81.7%; f. I2=89.0%; g. I2=95.7%; h. I2=96.9%; i. I2=95.5%; j. I2=71.1%; k. I2=81.7%; l. I2=82.5%; m. I2=98.5%; n. I2=97.3%; o. The total sample size was less than the optimal information size, p. The 95%CI of the pooled estimate included one or no effect; q. The total sample size was less than 400.