Optimizing Iron Overload Screening in a Pediatric Center for Cancer and Blood Disorders

Background: Packed red blood cell (PRBC) transfusions are common in the management of pediatric hematology, oncology, and bone marrow transplant (HOB) patients, and can lead to accumulation of excess iron that the body is unable to excrete. Increased exposure can lead to the development of iron overload (IO), which results in toxic effects on the liver, heart, and endocrine organs. Treatment can reduce the body's iron burden and improve outcomes. Previous studies observed that patients who received >10 PRBC transfusions or had an elevated serum ferritin were at a higher risk of IO. Unfortunately, published guidelines for IO screening only exist for a minority of HOB patient subtypes (thalassemia, sickle cell, and bone marrow transplant). The Children's Hospital Colorado Center for Cancer and Blood Disorders (CCBD) lacked a system to track transfusion frequency and a standardized guideline to adequately screen for IO, which made this a prime process improvement opportunity.

Objective: Improve screening for IO by increasing the percentage of CCBD patients with >10 PRBC transfusions who have received a serum ferritin to >75%.

Methods: All patients seen in CCBD clinics in 2015 were evaluated for the total number of transfusions received prior to 2016 and whether additional workup for IO was obtained. With this baseline data, a multidisciplinary working group created 3 interventions to improve identification and screening of IO.First, initial screening recommendations were integrated into the electronic health record (EHR) to alert providers when a patient has had >10 PRBC transfusions, prompting them to order a screening serum ferritin. Second, after a review of existing literature and discussion with local content experts, a risk-based screening algorithm was created and linked to the EHR alert to guide further testing. The algorithm recommends obtaining a liver and cardiac MRI for iron content in patients with a ferritin persistently >500 ng/mL. It also provides recommendations for phlebotomy or chelation in patients with liver and/or cardiac IO based on MRI findings. Third, providers were educated on IO screening and treatment. Data on screening practices will be collected and analyzed on an ongoing basis to track the response to the interventions and modify our approach, if needed.

Results: Analysis of preliminary data from 2015 demonstrates that 19% of patients seen in CCBD clinics had >10 transfusions (192/1006). The percentage of patients with >10 transfusions that had a serum ferritin drawn was 53% (101/192). However, only 45% of patients had a ferritin obtained after receiving 10 transfusions (86/192). The most common sub-group was patients with oncology diagnoses (94/192, 49%), but only 14% (13/94) of oncology patients had a screening ferritin after 10 transfusions. In contrast, 90% (26/29) of hematology and 68% (47/69) of bone marrow transplant (BMT) patients had a screening ferritin. The mean time to obtaining a ferritin after 10 transfusions was 392 days. When evaluating all patients who had a ferritin sent, the value was >500 ng/ml in 80% (81/101) and >1000 ng/ml in 60% (61/101). Despite having a ferritin >500 ng/ml, only 46% (37/81) of patients received additional testing with a cardiac and/or liver MRI for iron content. There is ongoing collection and analysis of data evaluating improvements in screening practices since the EHR alert, risk based screening algorithm, and staff education began.

Conclusions: Relatively few CCBD patients at risk for IO received initial screening, and even fewer had additional testing to evaluate for organ based IO. One reason that fewer oncology patients were screened may be the lack of an available guideline for IO screening. In contrast, available screening recommendations for sickle cell, thalassemia, and BMT patients may explain the increased frequency of screening in hematology and BMT patients. However, even patients who were screened and had an elevated ferritin did not uniformly receive additional testing with a cardiac and/or liver MRI. The goal of this project is to establish a baseline percentage of high-risk patients screened for IO, and then increase this level using a CCBD-wide standardized approach of staff education and EHR lab test prompts according to a standardized algorithm. As a result of the proposed interventions patents may be diagnosed earlier and subsequently treated when the disease burden is lower.