ID was significantly more frequent in patients with > 3 comorbidities (65.6% vs. 55.9%; p = 0.0274), those receiving a treatment with a possible impact on ID or anemia (60.5% vs. 49.6%; p = 0.0042) or those with CRP ≥ 5 mg (64.8% vs. 49.6%; p < 0.001). Here, CRP is linked to anemia.