The Cox proportional hazards model revealed that after adjusting for age, sex, and comorbidities, the risk of incident dementia was reduced both among HD patients who had received both EPO and iron (adjusted HR = 0.49, 95% CI, 0.41–0.58), and those who had used EPO but not iron (adjusted HR = 0.68, 95% CI, 0.59–0.78). This evidence concerns the gene EPO and dementia.