- What is a futility analysis in clinical trials?
- What is group sequential design?
- What is conditional power?
- What is Alpha in a clinical trial?
- What is a nominal P value?
- What is a sequential clinical trial?
- What do you mean by sequential analysis?
- What does P mean in clinical trials?
- What does N mean in clinical trials?
- What is Alpha spending?
What is a futility analysis in clinical trials?
The term ‘futility’ is used to refer to the inability of a clinical trial to achieve its objectives.
In particular, stopping a clinical trial when the interim results suggest that it is unlikely to achieve statistical significance can save resources that could be used on more promising research..
What is group sequential design?
Group sequential design is an example of a statistical approach in clinical trial design. It means that the sample size of the trial is not fixed in advance, and data is sequentially evaluated as it is collected. This is known as interim analysis, and might be carried out at several points in time.
What is conditional power?
Conditional power (CP) is the probability that the final study result will be statistically significant, given the data observed thus far and a specific assumption about the pattern of the data to be observed in the remainder of the study, such as assuming the original design effect, or the effect estimated from the …
What is Alpha in a clinical trial?
The probability of making an error is called α (“alpha”) and the probability of avoiding error is 1–α. Rather than specify alpha ahead of time, many people like to look afterwards and see what the risk of Type I error is for the data actually obtained. This is called the p–value.
What is a nominal P value?
The nominal p-value is a calculated observed significance based on a given statistical model. When the statistical model reflects the actual test performed the nominal and actual p-value coincide. … Violating any of the prerequisites of a significance test will render the nominal p-value more or less non-actionable.
What is a sequential clinical trial?
Sequential trials are pre-planned, repeated series of comparisons that are stopped as soon as a decision can be made as to whether one treatment can be regarded as superior to another, or that both are equally effective.
What do you mean by sequential analysis?
Sequential analysis refers to a statistical method in which data are evaluated as they are collected, and further sampling is stopped in accordance with a predefined stopping rule as soon as significant results are observed. This contrasts to classical hypothesis testing where the sample size is fixed in advance.
What does P mean in clinical trials?
group differenceA P value is defined as the probability of observing treatment effect (eg, group difference in mean response) as extreme or more extreme (away from the H0) if the H0 is true. Hence, the smaller the P value, the more extreme or rare the observed data are, given the H0 to be true.
What does N mean in clinical trials?
“Active” (n=101) Placebo. (n=102) Active – Placebo.
What is Alpha spending?
Alpha-spending is an approach of distributing (spending) the type I error (denoted alpha) over the duration of a sequential A/B test. Alpha-spending makes it possible to perform sequential testing while maintaining the overall error probability of the procedure.