HP and Cognitive impairment: Cumulative survival plots of impairment-free cognition according to Hp phenotype revealed that patients with SAH expressing Hp1-1 (HR: 0.159, 95% CI: 0.084–0.299) and Hp2-1 (HR: 0.416, 95% CI: 0.258–0.671) had less cognitive impairment compared with those manifesting Hp2-2 (p for log-rank test < 0.001) (Figure 2A).