Treatment status of iron medications for anemia in patients visiting gynecological or obstetric facilities: analyses using Japanese claims data

Background Anemia is highly prevalent among women of reproductive age and can have negative health effects. Thus, appropriate and effective treatment is essential to mitigate these effects. This study assessed the current treatment status of iron-deficiency anemia in this population. Methods Data from women aged 20–49 years who visited gynecological or obstetric facilities were analyzed using a Japanese health insurance claims database (June 2018–August 2022) provided by DeSC Healthcare, Inc.; the database included health checkup data. Patients were identified based on diagnoses of gynecological or obstetric disorders, diagnoses of obstetric supervision, or family identification based on a newborn baby. The duration of oral iron administration, the amount of iron replenished by intravenous (IV) iron infusions (saccharated ferric oxide [SFO] or ferric carboxymaltose [FCM]), and the status of oral iron medication prescriptions following IV iron infusions were analyzed. Results The median treatment durations with oral iron were 4.1 weeks for all patients, 4.4 weeks for those with Hb levels of 8–10 g/dL, and 8.7 weeks for those with Hb levels < 8 g/dL. The doses of IV iron preparations, particularly SFO, were often lower than the required doses calculated based on Hb levels and body weight. The required dose was achieved in 0.7% of the total administration episodes for SFO and in 46.4% of those for FCM. Oral iron medications were prescribed within 4 weeks after IV infusion for 37.5% of the SFO administration episodes and 20.8% of the FCM administration episodes. The iron dose administered per episode via oral medications exceeded that administered via IV infusions with SFO. Conclusions Treatment duration of approximately 1 month with oral iron appears insufficient to fully replenish iron reserves. IV iron therapy doses were often lower than required. Despite recommendations against following IV iron therapy with oral iron treatment, frequent use of oral iron medications was observed shortly after IV infusion. Considering the potential negative effects of anemia, women of reproductive age should receive appropriate and effective treatment for iron-deficiency anemia, regardless of the presence of subjective symptoms.