Patient Factors Associated with Prescribing of Iron for IV Administration: A Descriptive Study

IV administration of iron is appropriate for the treatment of iron deficiency anemia (IDA) when orally administered iron has not been effective, tolerated, or clinically appropriate. In Calgary, Alberta, high levels of IV iron utilization required review, because of significant health care resource utilization, high cost, and reduced accessibility.

The primary objective was to describe the population of adult patients in Calgary with estimated glomerular filtration rate greater than or equal to 30 mL/min/1.73 m² for whom IV iron was dispensed from acute care facilities, in terms of pretreatment laboratory data, previous use of oral iron, and treatment location, as well as to characterize dose and product selection for IV iron. The secondary objective was to determine the proportion of inpatients whose treatment was in alignment with the Toward Optimized Practice clinical practice guideline for IDA.

A retrospective review of electronic charts was used to obtain data about patients with a first dose of IV iron dispensed in Calgary hospitals between March 1 and December 31, 2018. The data were analyzed descriptively.

A total of 1352 patients met the inclusion criteria. These patients received a total of 3532 doses of IV iron, 97.1% of which were iron sucrose, at a median of 300 mg per infusion. Laboratory indices assessed before the first infusion were hemoglobin (mean 92, standard deviation [SD] 19.6 g/L), mean corpuscular volume (mean 81 [SD 10.3] fL), and ferritin (median 18 [interquartile range 9-48] μg/L). Among the included patients, 233 (17.2%) had oral iron dispensed within 90 days before their first IV dose of iron. Only 146 (20.1%) of the 726 inpatients had treatment that was in alignment with the Toward Optimized Practice IDA guideline.

There was substantial variation in baseline hemoglobin, mean corpuscular volume, and ferritin, and in the use of oral iron before initiation of IV iron treatment. Provision of educational tools and stewardship initiatives may help in ensuring alignment of iron prescribing with current guidelines.