Summary of findings 2. Airway bypass stents versus control.
| Airway bypass stents versus sham bronchoscopy for the treatment of chronic obstructive pulmonary disease | ||||||
| Patient or population: Participants suffering from chronic obstructive pulmonary disease Setting: Hospital Intervention: Airway bypass stents + optimal medical care Comparison: Sham bronchoscopy + optimal medical care | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with optimal medical care | Risk with bypass stents | |||||
| % Change from baseline in FEV1 | The mean % change in FEV1 for control was ‐1.1% (SD 3) | The mean % change in FEV1 in the intervention group was 0.95% higher (95% CI ‐0.16 to 2.06) | ‐ | 350 (1 RCT) | ⊕⊕⊕⊕ HIGH | |
| Mortality at end of follow‐up | 37 per 1,000 | 29 per 1,000 | OR 0.76 (0.21 to 2.77) | 350 (1 RCT) | ⊕⊕⊕⊝ MODERATE1 | |
| Units SGRQ at end of follow‐up | The mean units of SGRQ for control at end of follow‐up were 58 (SD 15) | The mean units of SGRQ for the intervention group at end of follow‐up was 2 units lower (95% CI ‐5.58 to 1.58) | ‐ | 350 (1 RCT) | ⊕⊕⊕⊕ HIGH | The CI did not reach the MCID used in this review (‐7.1 units), meaning that, with the current state of the treatment, we do not expect the result to change; hence no downgrading of the evidence was performed. |
| Change from baseline in lung function parameters other than FEV1 | The mean L change in RV for control was ‐0.10 L (SD 0.6) | The mean L change in RV for the intervention group at end of follow‐up was 0.04 L more (95% CI ‐0.11 to 0.19) | ‐ | 350 (1 RCT) | ⊕⊕⊕⊕ HIGH | The CI did not reach the MCID used in this review (0.43 L), meaning that, with the current state of the treatment, we do not expect the result to change; hence no downgrading of the evidence was performed. |
| The mean L change in FVC for control was 0.0L (SD 0.4 L) | The mean L change in FVC for intervention was 0.08 L fewer (95% CI ‐0.18 to 0.02) | ‐ | 350 (1 RCT) | ⊕⊕⊕⊕ HIGH | ||
| Meters 6MWD at end of follow‐up | The mean 6MWD for control at end of follow‐up was 297 meters (SD 94) | The mean 6MWD for intervention at end of follow‐up was 16.00 meters fewer (95% CI ‐39.17 to 7.17) | ‐ | 350 (1 RCT) | ⊕⊕⊕⊝ MODERATE2 | |
| Adverse events at end of follow‐up | 112 per 1,000 | 144 per 1,000 (76 to 256) | OR 1.33 (0.65 to 2.73) | 315 (1 study) | ⊕⊕⊕⊝ MODERATE3 | Serious adverse events were reported in 3.4% (n = 7) participants in the treatment group compared to none in the sham control group. Pneumothorax (3 in treatment versus 1 in control), haemoptysis (1 in treatment versus 0 in control) and COPD exacerbations (33 in treatment versus 9 in control) were more frequent in treatment versus sham control. |
| Cost effectiveness | Not reported | not estimable | ||||
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio; OR: Odds ratio; SGRQ: St George's Respiratory Questionnaire; FEV1: forced expired volume in one second; RV: Residual Volume; TLC: Total lung capacity; L: Liter; RCT: randomized controlled trial; 6MWD: Six‐Minute Walking Distance; SMD: Standardized Mean Difference; MD: Mean Difference | ||||||
| GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | ||||||
1Downgraded 1 level for imprecision: the upper end of CI indicates more than 2.7 times the odds of events and lower CI is below 1.
2Downgraded 1 level for imprecision: the lower end of CI indicates crosses the MCID used for this outcome (26 meters).
3Downgraded 1 level for imprecision: the upper end of CI indicates more than 2.7 times the odds of events and lower CI is below 1.