Finally, we estimated whether modelling the SBP/APOE ɛ4 genotype interaction improved predictive ability for post-ICH outcomes, and found significant differences (compared with models including both variables but no interaction term) for prediction of future risk of ICH recurrence, ischaemic stroke, dementia, depression and gait impairment (Supplementary Table 10). Here, APOE is linked to major depressive disorder.