Analysis methods: What characteristics may impact how well a treatment works (Subgroup analyses)

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  • What does it mean?
Subgroup analyses try to find out whether the effect of a treatment is different for different types of people (e.g. men and women or different age groups). Subgroup analyses are usually defined at the start of a trial, but may be discussed later on. Any subgroup analyses should be well justified as it can lead to wrong results or interpretation if not planned carefully. You can read more about subgroup analyses and how they can be tricky to interpret here. 

  • An example
In our toothpaste trial, we might be interested in finding out whether the effect of toothpaste A when compared with toothpaste B varies depending on the patient's age. For that reason, we will collect participant's age at the start of the trial and present the treatment results by age group.
  • How can patients be involved?
Patients could be involved in the discussions about what characteristics might be important to measure to explore differences in how well a treatment work.  

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