The RRs and 95 % CI are represented by the data in each grid, evaluated between agents from top-left to bottom-right. The blue areas represent the agents, the green areas represent the safety of AEs (RR and 95% CI) between different agents, and the orange areas represent the safety of SAEs (RR and 95% CI). AEs: adverse events; SAEs: serious adverse events; ESAs: erythropoiesis-stimulating agents; RR: risk ratio; 95% CI: 95% confidence interval.