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Simplifying the Facts of Non-Inferiority Trials: Introduction

Simplifying the facts of non-inferiority trials: Introduction
Well now that we’ve covered superiority trials I definitely wanted to make sure that I cover non-inferiority trials these are what’s hot in the literature right now and so I want to make sure that you have the tools to be able to evaluate these trials as well. So from these learning objectives we’re gonna learn how to formulate a null hypothesis for a non-inferiority trial and I’ll compare this back to the superiority ones that we discussed before. We’re going to look at the potential outcomes of an NI study design. We’re gonna see if what the type 2 type one and type two errors look like in an NI study compared to a superiority.
We’re going to look at resources where you can find where an appropriate NI margin is for different disease states. We’re going to interpret p-values and confidence intervals in and out in NI trial and build on what we’ve discussed in previous lectures. We’re going to determine whether NI and/or superiority were met given an excerpt from an NI study We’ll describe which analysis set either an ITT or per protocol should be used for an NI study and its rationale for use. We’re going to verify when it is acceptable for an NI study to determine superiority and one is acceptable for a superiority to study to define non-inferiority. Now again this is an introduction superiority non-inferiority trials have different criterias for assessment.
Unfortunately both types of trial designs have been found to be flawed and superiority studies actually are considered superior to non-inferiority trials if those can be done. So you think that there’s a lot of errors in previous studies we’ll find that there will be even more in non-inferiority studies and hopefully that will improve as more and more people become familiar with them. So again there’s the consort statement that’s the gold standard for randomized controlled trials.
It’s got a checklist of what should be in there and there’s another and there’s a supplement one for non-inferiority trials But again with everything else that we’ve discussed you’ve got to critique the entire trial not just this the statistical aspects and not just the mathematical aspects we need to look at is there good internal validity is the study design correctly to be able to provide that external validity.
Now if you missed I didn’t also tell you about I gave you consort which is where you can as you can see a randomized clinical trials which is the gold standard for that but you can see there are other guidelines for analyzing different types of trials that you can find on the equator website that I have there for you. So what is an NI trial supposed to do? It’s supposed to look at true treatments and determine if one is nearly as beneficial or not inferior. And so how what kind of key elements are we going to look at an NI trial that may differ a little bit from what we look in superiority?
Well we definitely need to make sure that that non-inferiority trials have a similar population with the same prognosis. In other words inclusion and exclusion criteria, as the previous trials of placebo controlled that we’ll get some information from. It also has to be a proven drug to be better than at least placebo and it has to be a dose provided with that.
We need to make sure that it’s an appropriate clinical outcome and an adequate study duration and there has to be a high level patient adherence to treatment because we’ll see when we talk about ITT vs PP that that’s going to have a huge potential to cause a treatment to look not inferior if it’s not if patients are not adherent. And then again we’re going to see the CIs that are going to provide us that information as far as whether the test drug was better than control We’ll also look at something new called a delta margin and how that is analyzed and what adequate power that you’ll need. And again ITT and PP results.
We’ll talk a little bit about that and how that may differ from what you’d use in a superiority trial and then we need to look at a safety assessment. Because in a non-inferiority trial there’s really no reason to look at a drug that may be nearly as good unless it’s got either a better safety profile or something else that would cause you to want to investigate another treatment option.

Prof. Mary Ferrill lists the learning objectives for this lesson and gives a brief introduction.

There are nine objectives for this lesson, including formulating a null hypothesis for a noninferiority (NI) trial, listing the potential outcomes for an NI study design, and defining a type I or type II error in NI study designs.

Besides, If we find plenty of errors in previous superior studies, we are going to find that there will be even more errors in non-inferiority studies.

A CONSORT statement, which means consolidated standards of reporting trials, is the gold standard for randomized controlled trials providing checklists and examples of good and bad studies in each area.

Also, we are given other guidelines for analyzing different types of trials which can be found on the Equator website.

What are the purposes and the key elements of an NI trial?

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Evidence-Based Medicine in Clinical Pharmacy Practice

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