Neglecting to consider or include subgroup analysis in cost-effectiveness analysis may mask key differences between subgroups and result in suboptimal resource allocation.

Given the quantity and range of factors limiting subgroup analysis, we encourage future researchers to be more explicit in reporting if subgroup analysis has not been presented.

Researchers and decision makers must be aware of the barriers and challenges around conducting subgroup analysis, in order to identify solutions to conduct robust subgroup analysis or to understand the potential limitations of more exploratory analysis.