Discover and read the best of Twitter Threads about #noninferiority
Most recents (3)
A clinical trial design that is often misunderstood is the #NonInferiority clinical trial design. 1/8
#MethodologyMonday
#MethodologyMonday
Mostly we set up trials to test if a new treatment is better than another (ie we test for superiority) but in a #NonInferiority design we wish to test if a treatment is not unacceptably worse than a comparator. 2/8 
The main reasons why we might look for non-inferiority is when an alternative treatment is say much cheaper, or has fewer side effects … but we would only wish to use it if the benefits of the standard treatment are not significantly compromised. 3/8
onlinelibrary.wiley.com/doi/full/10.10…
onlinelibrary.wiley.com/doi/full/10.10…
1/ What are 3 Qs you can ask yourself when looking at non-inferiority trials?
Q1) Was the trial planned i.e. pre-specified as comparing an intervention which is non-inferior to control?
WHY?
Bc changing the analysis *afterwards* introduces bias #StatswithCoreIM
Q1) Was the trial planned i.e. pre-specified as comparing an intervention which is non-inferior to control?
WHY?
Bc changing the analysis *afterwards* introduces bias #StatswithCoreIM
2/ Q2) was the control treatment administered to the full std of care?
The trial relies on strict adherence to full standard of care for the control arm, otherwise the whole confidence interval shifts with a relative⬆️in benefit of the intervention compared to control
The trial relies on strict adherence to full standard of care for the control arm, otherwise the whole confidence interval shifts with a relative⬆️in benefit of the intervention compared to control
3/ Q3) Did investigators perform both a per protocol and intention to treat analysis?
Per protocol:
Exaggerates group difference when intervention is inferior
Less likely to result in false positive
Intention to treat:
Makes groups prognostically 🟰
Benefit of randomization
Per protocol:
Exaggerates group difference when intervention is inferior
Less likely to result in false positive
Intention to treat:
Makes groups prognostically 🟰
Benefit of randomization
1/ Let’s dive into #noninferiority trials for this edition of #StatswithCoreIM
But first, take a look at this figure for what superiority trials aim to assess: What’s better?
But first, take a look at this figure for what superiority trials aim to assess: What’s better?
2/ So how are NON-inferiority trials different?
They ask if a treatment is much worse than standard of care.
They ask if a treatment is much worse than standard of care.
3/ Let’s look at the possible outcomes of a non-inferiority trial.
✔️Superior and non-inferior
✔️Non-inferior
✔️Not non-inferior
✔️Inferior and not non-inferior
✔️Inferior and non-inferior
✔️Superior and non-inferior
✔️Non-inferior
✔️Not non-inferior
✔️Inferior and not non-inferior
✔️Inferior and non-inferior
