Evidence
This page contains a snapshot of featured content which highlights evidence addressing key clinical questions including areas of uncertainty. Please see the main topic reference list for details of all sources underpinning this topic.
BMJ Best Practice evidence tables
Evidence tables provide easily navigated layers of evidence in the context of specific clinical questions, using GRADE and a BMJ Best Practice Effectiveness rating. Follow the links at the bottom of the table, which go to the related evidence score in the main topic text, providing additional context for the clinical question. Find out more about our evidence tables.
This table is a summary of the analysis reported in a Cochrane Clinical Answer that focuses on the above important clinical question.
Confidence in the evidence is moderate or low to moderate where GRADE has been performed and the intervention may be more effective/beneficial than the comparison for key outcomes.
Population: People with acute hypercapnic respiratory failure due to chronic obstructive pulmonary disease exacerbation
Intervention: NIV plus usual care
Comparison: Usual care alone (combinations of pharmacologic therapies)
Outcome | Effectiveness (BMJ rating)? | Confidence in evidence (GRADE)? |
---|---|---|
Mortality (where reported, duration of follow‐up to intensive care unit [ICU] or hospital discharge) | Favors intervention | Moderate |
Need for endotracheal intubation (where reported, duration of follow‐up 3 days to 30 days, ICU discharge, or hospital discharge) | Favors intervention | Moderate |
Symptom scores (1 hour to 3 days) | No statistically significant difference | GRADE assessment not performed for this outcome |
Duration of ICU stay | No statistically significant difference | GRADE assessment not performed for this outcome |
Duration of hospital stay | Favors intervention | Moderate |
Treatment intolerance | Favors comparison | GRADE assessment not performed for this outcome |
Partial pressure of carbon dioxide (PaCO2; 1 hour postintervention) | No statistically significant difference | GRADE assessment not performed for this outcome |
Partial pressure of oxygen (PaO2; 1 hour postintervention) | Favors intervention | GRADE assessment not performed for this outcome |
Complications of treatment: NIV-related | See note ᵃ | GRADE assessment not performed for this outcome |
Complications of treatment: NonNIV-related | Occurs more commonly with usual care alone compared with NIV plus usual care (favors intervention) | GRADE assessment not performed for this outcome |
Note ᵃ 30% of people in the NIV plus usual care group had complications specifically related to NIV (not experienced in the usual care alone groups). See Cochrane Clinical Answer (CCA) for more details.
This evidence table is related to the following section/s:
Cochrane Clinical Answers

Cochrane Clinical Answers (CCAs) provide a readable, digestible, clinically focused entry point to rigorous research from Cochrane systematic reviews. They are designed to be actionable and to inform decision making at the point of care and have been added to relevant sections of the main Best Practice text.
- How does longer corticosteroid treatment (>7 days) compare with shorter (≤7 days) in people with exacerbations of chronic obstructive pulmonary disease?
- What is the impact of airway clearance techniques when treating acute exacerbations of COPD?
- How do antibiotics compare with placebo in people admitted to hospital or to the intensive care unit with exacerbations of chronic obstructive pulmonary disease?
- How does non-invasive ventilation compare with usual care in people with acute hypercapnic respiratory failure due to exacerbation of chronic obstructive pulmonary disease?
- What are the effects of hospital-at-home in adults with acute exacerbations of chronic obstructive pulmonary disease?
- What are the effects of action plans with limited patient education only in reducing exacerbations of chronic obstructive pulmonary disease?
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