Subgroup analysis is important for investigating differences in how people respond to a treatment or intervention. But when misused, it can result in misleading findings. That's why it's important to understand the risks associated with this kind of analysis and to know what to look for when you come across it.

What is the purpose of subgroups?

The main aim of a subgroup analysis is to identify either consistency of or large differences in the magnitude of treatment effect among different categories of patients.

What are subgroups in research?

Subgroups, by definition, are smaller than the main study and typically have less statistical power to identify subtle effects. False-negative results may mislead readers into thinking there is no benefit in a subgroup, when in fact there is a benefit that the analysis doesn't have enough statistical power to detect.