It's always about numerators and denominators (N/D)

According to the authors, sex-based participation disparities and lack of sex-related analyses and reporting limit the generalizability of research findings and hamper the external validity of the effectiveness of interventions. In a systematic review Yu et al. evaluated the degree of personalization of benefit and harm results of RCTs of pharmacological therapy published in the McMaster Premium LiteratUre Service (PLUS) database [5], with the proportion of trials reporting subgroup analyses of a combined benefit-harm outcome as primary outcome and the proportion of trials reporting subgroup analyses or clinical prediction guides for benefits or harms as secondary outcomes. Webster-Clark c.s., considering that effect estimates from prespecified subgroups may not apply to corresponding subgroups in the source population, studied whether systematic or structural sources of misleading subgroup estimates could play a role here by using directed acyclic graphs to evaluate selection bias. According to the authors it can be misleading to assume that subgroups within a trial are random samples of corresponding subgroups in the wider population.