Iron administration and clinical outcomes in hemodialysis patients.

To evaluate the impact of parenteral iron administration on the survival and rate of hospitalization of US hemodialysis patients, a nonconcurrent cohort study of 10,169 hemodialysis patients in the United States in 1994 was conducted. The main outcome measures were patient survival and rate of hospitalization. After adjusting for 23 demographic and comorbidity characteristics among 5833 patients included in multivariable analysis, bills for <or=10 vials of iron over 6 mo showed no adverse effect on survival (adjusted relative risk [RR] = 0.93; 95% confidence interval [CI], 0.84 to 1.02; P = 0.14) when compared with none, but bills for >10 vials showed a statistically significant elevated rate of death (adjusted RR = 1.11; 95% CI, 1.00 to 1.24; P = 0.05). Bills for <or=10 vials of iron over 6 mo also showed no significant association with hospitalization (adjusted RR = 0.92; 95% CI, 0.83 to 1.03; P = 0.15), but bills for >10 vials showed statistically significant elevated risk (adjusted RR = 1.12; 95% CI, 1.01 to 1.25; P = 0.03). Prescribing iron in quantities of <or=10 vials over 6 mo had no association with an elevated risk of death or rate of hospitalization. More intensive dosing was associated with diminished survival and higher rates of hospitalization, even after extensive adjustment for baseline comorbidity. Although these potential risks may be offset by the known elevations in morbidity and mortality associated with anemia, these findings indicate that caution is warranted when prescribing >10 vials (1000 mg) of iron dextran over a period of 6 mo.