Building up your table of comparisons
The table below is designed to help you construct your review question and subsequently set your inclusion and exclusion criteria. Using what you have learned and thought about in the above section, complete this table and finalise your question.
| Participants |
What are the people (or other participants) receiving the intervention to be like?
Men or Women?
All ages or with a cut off?
How would you define the disease/ condition participants should have?
Who should make the diagnosis?
Are there any co-morbidities you want to exclude?
Are there any other types of people who should be excluded from your review (because they are likely to react to the intervention in a different way)?
In one sentence describe your population, for example "All adults with tennis elbow (pain on lateral aspect of the elbow aggravated by use of the wrist or hand), diagnosed by a health care worker.
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| Interventions |
What is the intervention you are interested in?
Does it have variations (eg dosage, mode of delivery, who delivers it)?
Are you going to include all variations or set parameters (for example is there a critical dose below which you think the intervention is not clinically appropriate and so trials of intervention below this dose should not be included in the review)?
What are you going to do with trials including only part of the intervention? What are you going to do with trials including your intervention combined with another intervention (co-intervention)?
In one sentence describe your intervention.
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| Comparisons |
What are you interested in comparing the intervention to? This depends on the primary question of the review. Are you only interested in whether the intervention offers benefit over the natural course of the disorder (ie a comparison to placebo or no treatment), or are you interested in whether the intervention offers benefit over other interventions.List your possible comparisons:
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| Outcomes |
How do you think it is important to measure change with respect to this intervention in this population?
List all the outcomes you are including in your review. You should consider all those likely to be important to those suffering the disorder as well as those treating them. Don't forget to consider if there is a need to include adverse effects.
Divide your outcomes into primary (essential) outcomes and secondary. The main conclusions of your review will be based on the primary outcomes (usually three or fewer) so give this considerable thought.
Finally, give some thought to how your outcomes may be measured, both the type of scale or count likely to be used and the timing of the measurement. Are there any methods of measurement or times you want to exclude (for example there may be a certain duration before which you feel the intervention could not work, and so you may want to exclude trials measuring the intervention before that point. Or, you may feel a particular method of measurement or primary outcome is not valid and you may want to exclude trials measuring the outcome in that way.
List any exclusions you have here:
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| Types of study |
There may be some study methodology aspects that, if present, you feel renders that study so invalid to your review that it should be excluded. Some more common ones are lack of randomisation, failure to conceal allocation or, in reviews where the outcomes are very subjective (eg global assessment of improvement or levels of depression), blinding of the outcome assessor.
Are there any exclusions related to trial methodology in your review?
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| Review title |
As we have discussed already, the title of a Cochrane review usually follows the format:
Intervention for Problem in Category
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