subgroup analyses

Question 1

what is the difference between a confirmatory and exploratory subgroup analysis

Answer 1

Confirmatory subgroup analysis - tests pre-specified hypotheses about treatment effects in specific subgroups of the study population. subgroups of interest and the statistical methods to be used are determined prior to conducting the study. Confirms if the treatment effect is consistent across subgroups

Exploratory subgroup analysis, - identifies potential treatment effects in subgroups that were not pre-specified in the study design. In this type of analysis, researchers may examine treatment effects in multiple subgroups or conduct post-hoc analyses based on observed data patterns. identifies any part of patient population that might benefit or be harmed from treatment

Question 2

issues with subgroup analysis

Answer 2

issues of multiple comparisons when conducting subgroup analysis, and that any interpretation of subgroup analysis results should be done with caution.

important to conduct confirmatory testing on the primary analysis population before conducting any subgroup analysis. helps to ensure that the primary analysis is robust and that any subgroup analyses are based on a strong foundation

also - smaller number of n in a subgroup, results therefore less reliable

Question 3

when do we need to specify the subgroup effects you seek to carry out? why?

Answer 3

In thte protocol, this is because the study can be designed with the with enough power to detect subgroup effects

Question 4

why is it a problem if we decide to look at subgroup efects in the analysis stage of a trial

Answer 4

Becuase the study was not designed to detect subgroup effects thus l;acks the statistical power

Question 5

if we decide to look at subgroup effects later on in the analysis stage, what must we consider this type of analysis?

Answer 5

Exploratory