A non-inferiority trial is a clinical study that aims to show a new treatment isn't much worse than an existing one. It uses a pre-set margin to define the maximum acceptable difference in outcomes, like recovery rates. Patients are randomly assigned to either the new or standard treatment, and their outcomes are compared. If the difference falls within the margin, the new treatment is considered "not inferior". These trials are useful when the new treatment might have other benefits, like fewer side effects or lower cost, without losing much effectiveness.
An equivalence trial is a clinical study to see if a new treatment is as effective as an existing one. It aims to show that the new treatment is neither much better nor worse than the standard treatment within an acceptable range, called the equivalence margin. Participants are randomly assigned to either the new or standard treatment and the outcomes, such as recovery rates or symptom relief are measured. If the differences fall within the margin the new treatment is considered equivalent. These trials are useful for introducing new versions or delivery methods of existing medications and ensuring they work just as well.
A superiority trial is a clinical study to see if a new treatment is more effective than an existing one or a placebo. It starts with the idea that the new treatment will work better. Participants are randomly assigned to either the new treatment or a control group to ensure fair comparison. Researchers measure outcomes like symptom improvement or recovery rates and analyse the differences using statistical methods. If the new treatment shows significantly better results it is considered superior. If not, it's seen as no better than the control. These trials are important for proving that new treatments offer better outcomes.