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 systematic review that focuses on the above important clinical question.
Confidence in the evidence is high or moderate to high where GRADE has been performed and there is no difference in effectiveness between the intervention and comparison for key outcomes.
Population: Adults with COPD
Intervention: Oral vitamin D supplements
Comparison: Oral placebo
| Outcome | Effectiveness (BMJ rating)? | Confidence in evidence (GRADE)? |
|---|---|---|
Rate ratio, moderate or severe exacerbations (overall) | No statistically significant difference | High |
Rate ratio, moderate or severe exacerbations (baseline serum 25-hydroxyvitamin D <25 nanomoles/L) | Favors intervention | Moderate |
Rate ratio, moderate or severe exacerbations (baseline serum 25-hydroxyvitamin D ≥25 nanomoles/L) | No statistically significant difference | High |
Proportion with ≥1 severe exacerbation | No statistically significant difference | High |
Proportion with ≥1 serious adverse event | No statistically significant difference | High |
Note The systematic review notes that the protective effects of vitamin D supplementation against COPD exacerbations is limited to people with the lowest baseline serum 25-hydroxyvitamin D concentrations only.
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.
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