Misleading description

Subgroup analyses

Look out for results that are reported for a selected group of people within a study or systematic review.

Comparisons of interventions often report results for selected groups of participants, called “subgroups”. This is because people want to know whether the effect of a nutrition intervention differs for different types of people (e.g. men and women, or different age groups).

Analyses of subgroups are often poorly planned and reported. When the results of such subgroup analyses show an intervention has different effects in different subgroups of people, it is likely to be due to the play of chance, and unlikely to reflect true differences in the effect of an intervention.

REMEMBER: Effects of nutrition interventions that are based on the results for subgroups of people within comparisons of interventions, may be misleading.