Nevertheless, although Tumbes was the site with the highest anemia prevalence and thus should have also had higher eGFR values, we argue that because Tumbes is also the site with the highest prevalence of other relevant clinical risk factors (e.g., diabetes and hypertension), the potential protective effect of erythropoietin was outweighed by the negative effects of the other risk factors. Here, EPO is linked to anemia (phenotype).