Methods for additional analyses (e.g. subgroup analyses) {20b}
anaemia
ANAEMIA
In a large trial such as I’M WOMAN, baseline characteristics of participants that may influence the outcome should be evenly distributed between the treatment and placebo groups, so that any difference in outcome can be attributed to the intervention. However, it is still possible that a chance imbalance in important prognostic factors could influence the results. To investigate this possibility, an analysis adjusted for baseline risk will be conducted. A prognostic model will be built based on pre-specified baseline variables and used to estimate the predicted risk of the outcome at baseline.Planned subgroup analyses will be conducted on the primary outcome comparing tranexamic acid to placebo. Subgroup variables include severity of anaemia (no anaemia vs mild anaemia vs moderate/severe anaemia) and route of birth (vaginal vs caesarean). We will explore potential confounding in subgroup analyses. Randomisation creates treatment groups that are balanced; however, the strata of subgroups may not be balanced [