How to read a study page
Each study page carries a design label. The label tells you how much weight the result can bear.
The labels
- Meta-analysis. Combines the results of several trials. Only as good as the trials it includes.
- Review. Summarises the literature. It may or may not be systematic.
- Randomised controlled trial. Subjects are assigned by chance to the treatment or a comparison, often a placebo. This is the strongest single-study design.
- Controlled trial. Has a comparison group, but assignment was not random.
- Open-label, no control group. Everyone received the treatment and knew it. Improvement can come from the treatment, from time passing, or from expectation. The study cannot tell these apart.
- Observational study. Researchers recorded what happened without assigning treatment.
- Case series. A report on a small number of individuals.
- Laboratory study. Work in cells or laboratory animals. It shows a mechanism. It does not show an effect in patients.
Things to check on any study
- How many subjects took part.
- Whether there was a control group.
- How long the study ran.
- What was measured, and who measured it.
- Who funded the work.
Doses
A dose shown on a study page is the dose the researchers used. It is not a recommendation.