Research Guides

The Short Answer: Relative Risk vs. Absolute Risk A headline claiming something "cuts your risk by 50%" is reporting relative risk — how much bigger or smaller one group's risk is compared to …

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Number Needed to Treat (NNT): A Quick Definition Number needed to treat, or NNT, is the average number of people who would need to receive a treatment for one additional person to get the specific …

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A confidence interval is a range of numbers, not one single number, that shows how precise a study's estimate is. When a result is reported as "2 to 8," that whole range — not just the number in the …

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A clinical trial protocol amendment is a formal, dated change to a study's written plan — who can join, what gets measured, or how long it runs. It matters to you as a reader because a documented, …

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Clinical Trial Phases Explained: What Happens in Phase 1, 2, 3, and 4 Clinical trials progress through four main phases before a drug or treatment can reach the market, and a fifth phase of …

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Animal studies and in-vitro experiments are essential early steps in research, but they cannot predict how a treatment will actually behave in the human body. Species differences in metabolism, dosing …

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