Adherence to oral iron in adolescent females with iron deficiency secondary to heavy menstrual bleeding

Abstract Background: Iron deficiency (ID) is an important, but minimized, health issue among adolescent females in the US. ID is the known precursor to iron deficiency anemia (IDA), which in adolescent females, is often caused by heavy menstrual bleeding (HMB). Oral iron is often an appropriate first line treatment for ID and IDA, but can have side effects. In the case of poor response to oral iron, or inability to tolerate oral iron due to side effects, IV iron has shown to be safe and effective. Although, there is minimal research regarding when to utilize IV iron as first line treatment of ID. Objectives/Goal: To evaluate adherence to, and potential barriers for, oral iron treatment in adolescent females with ID +/- anemia secondary to HMB, and to assess current use of IV iron in these patients. Our goal is to determine which treatments for ID are most effective and how we can optimize care for these patients. Methods/Design: We analyzed visits at Children's Mercy, 01/01/2018-12/31/2023, for females aged 12-21 years with a diagnosis of ID +/- anemia and HMB, using retrospective chart review. We assessed age, ethnicity, medical co-morbidities, number of medications, hospitalization requirement for IDA or HMB, presence of mental health diagnoses, hemoglobin and ferritin at diagnosis and end of study period, oral iron trials, adherence to oral iron, barriers to adherence, IV iron trials, type of IV iron trialed, resolution of ID and anemia at the end of the study period, and recurrence of ID or anemia within the study period. Results: Of our study's 147 patients, 100(68%) did not have resolution of ID at the end of study period. Mean age was 14.39 with SD of 1.79. Overall, 58(39%) received IV iron. Of those who received IV iron, 31(66%) had resolution of their ID vs. only 16(34%) on oral iron. 66(45%) patients required packed red blood cell transfusion. Mean hemoglobin at time of diagnosis was 8.27(SD 2.75) and was 12.47(SD 1.99) at end of study period. Mean length of oral iron until IV iron received or ID resolved was 8 months(SD 8). 20% of patients prescribed oral iron reported never taking it, and 66% reported adequate adherence. 45 patients reported barriers to taking oral iron which included other reasons (26/45, 57.8%) followed by side effects(16/25, 35.6%). As patients increased in age, odds of resolution of ID decreased by 57%(OR 0.43,95%CI 0.13-0/97), p=.04. Conclusions: We have found that there was a clinically significant number of patients who did not have resolution of their iron deficiency at the end of the study period. This could show that we are not effectively treating ID. Oral iron was trialed by the majority of our patients, which is in line with other studies showing oral iron is generally first-line treatment for ID. A smaller portion of our patients received IV iron. Our study showed that ID was more often resolved in those who underwent IV iron treatment than those who underwent oral iron treatment, which shows that there could be benefit into looking into utilizing IV iron more often for treatment of ID. We also found that as the age of participants increased, they were less likely to have resolution of ID, indicating that there could be benefit from moving towards IV iron sooner for these patients. We predict that moving forward, especially with older patients and those with side effects to oral iron, there could be great benefit in utilizing IV iron as first-line treatment. Our study showing a large number of patients without resolution of ID after treatment shows us that there are still great strides to be made in the treatment of iron deficiency.