Background: Anaemia is the most common complication of inflammatory bowel disease (IBD). While 36–90% of IBD patients have iron deficiency (ID), about one-third have manifest anaemia. In IBD, ID results from chronic blood loss and poor iron intake and/or absorption, with symptoms of anaemia including fatigue, headache and shortness of breath or tachycardia, affecting patients' quality of life and use of healthcare resources. While oral iron is often still used as first-line therapy for ID or IDA (ID/A) in patients with IBD, IV iron is known be safe and effective, providing rapid replenishment of iron stores. This study aimed to compare hospitalisation rates of IBD patients with ID/A in Germany when newly treated with IV or oral iron.
Methods: Pooled anonymised individual claims data of ca. 75 German health insurances were searched to identify patients with Crohn's disease or ulcerative colitis and ID/A who first received oral or IV iron in 2013, with pre- and post-index periods of 4 and 3 quarters, respectively. Oral and IV iron groups were matched for age, gender and comorbidities. Outcome measures were the number and duration of hospitalisations, and ID/A-related inpatient stays were defined by ICD-10-GM codes as primary or secondary diagnosis.
Results: In total, 2,379 IBD patients were diagnosed with ID/A in 2013. Of these, 589 received oral iron and 442 patients IV iron, while 1,348 received no iron replacement. Most IV-treated patients (62.9%) received iron(III)-hydroxide-polymaltose complex, while 24.9% received iron(III)-sodium-gluconate complex. After matching, 380 patients remained in each treatment cohort. All-cause hospitalisation rates between matching and initiation of iron treatment were 38% (oral group) and 42% (IV group). ID/A-related hospitalisation was 4% in both cohorts. In the post-index period, significant differences between the cohorts were identified, with 48% vs. 37% all-cause (p=0.001), and 14% vs. 5% ID/A-related (p<0.001) hospitalisations in the oral and IV groups, respectively (Fig. 1). Mean duration of ID/A-related hospitalisation was significantly shorter after IV therapy (9.6 vs. 7.0 days; p<0.001), whereas the difference before treatment initiation was insignificant (1.9 vs. 2.4 days, p=0.67).
Conclusions: IV iron treatment was associated with fewer all-cause and ID/A-related hospitalisations after treatment. Moreover, duration of ID/A-related hospitalisations was reduced compared to patients treated with oral iron. Further research is warranted to assess long-term effects of iron treatment.