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ATLANTA -- A large proportion of children with sickle cell anemia (SCA) are not receiving transcranial Doppler ultrasound (TCD) screening to prevent strokes from the disease, or recommended treatment with hydroxyurea, according to a released Tuesday.

"This report points out less than half of children 2 to 16 years of age who were enrolled in Medicaid in 2019 were receiving the recommended annual screening to assess the risk of having a stroke," Laura Schieve, PhD, an epidemiologist at the CDC's National Center on Birth Defects and Developmental Disabilities, said on a phone call with reporters Tuesday. "The Vital Signs report also notes that only two in five children 2 to 9 years of age, and only about half of children and teens 10 to 16 years of age, are receiving treatment with a medication called hydroxyurea."

The report, released during National Sickle Cell Awareness Month, looked at data on 3,352 children and adolescents with SCA who were continuously enrolled in Medicaid in 2019. Researchers also examined change over time by including a sample of 3,858 children and adolescents continuously enrolled in Medicaid in 2014 and comparing them with the 2019 sample; the two samples had similar demographic and health profiles.

The authors noted that sickle cell disease (SCD) -- which includes SCA -- "primarily affects persons whose ancestors came from Africa, where malaria is endemic, because the sickle cell trait confers a selective advantage by protecting against the harmful effects of malaria. Thus, >90% of the estimated 100,000 persons in the United States with SCD are non-Hispanic Black or African American."

The study did include some encouraging news: from 2014 to 2019, TCD screening increased 27% among children and adolescents ages 10 to 16 years, and 9% among children ages 2 to 9, although the latter figure was not statistically significant. By 2019, 38% of children ages 10 to 16 and 47% of children ages 2 to 9 had received the TCD screening.

The use of screening is important, Schieve told 乌鸦传媒, because before screening became common, "there were several large studies that documented that by the age of 20, 11% of children with sickle cell anemia would develop a symptomatic stroke. And it is expected that the number of strokes might have even been higher because there can be many 'silent strokes,' which can cause brain injury even though there are no signs or symptoms." Children who are found to be at higher risk of stroke can be given transfusion therapy to lower their risk, she added.

Since the introduction of TCD screening and transfusion therapy, "there has been some evidence that hospitalizations for stroke among children with sickle cell anemia have decreased," Schieve noted. "But as this study shows, there is still a lot of work to be done, as half of the children and teens who are recommended and eligible to get TCD screening are still not getting recommended screening."

Schieve said that although the researchers weren't able to investigate the reasons why children were not getting screened, patients face logistical challenges including limited availability of appointments and difficulties getting transportation to the places that perform the screening.

In addition, "we also know that there's just a general lack of healthcare providers with expertise in sickle cell disease," she said. "And when patients do seek care -- and often they are seeking care in the emergency department -- there's particularly a lack of knowledge about their disease, and patients often report experiencing discrimination and feeling like they're not being taken seriously. So all of these are global, and the specific barriers and challenges that need to be faced."

To solve some of these problems, "hematologists and other healthcare leaders can work with policymakers and advocates to try to bring attention to racism and the impact that this has had on sickle cell funding, research, and policy decisions," Schieve said. "Healthcare systems can develop formal reporting systems to document and respond to racist behavior, and to empower people with sickle cell anemia to safely report their concerns about prejudice or inequity."

Regarding hydroxyurea treatment, the researchers found that from 2014 to 2019, hydroxyurea use rose 27% among children ages 2 to 9 and 23% among children ages 10 to 16. On the whole in 2019, 38% of children ages 2 to 9 were taking hydroxyurea, as were 53% of those ages 10 to 16. Hydroxyurea use was higher -- at more than 60% -- among children and adolescents ages 10 to 16 in particular subgroups, such as those who had been recently hospitalized, those who had three or more recent emergency department visits, and those who had a recent or previous acute chest syndrome hospitalization.

The numbers regarding hydroxyurea use "are both promising and disheartening when I look at them," because of both the high percentages of use in some subgroups, as well as the percentage that still isn't getting the drug, said Debra Houry, MD, MPH, CDC's acting principal deputy director. "These are children who should be receiving this medication. As we're looking at healthcare disparities, we have to question, why are there these gaps? At what point can we further lessen them so that we don't have these children experiencing these complications? ... We need to focus as providers and community members on how we can reduce those consequences through some of this screening and treatment."

Asked by 乌鸦传媒 whether there are any concerns providers or parents might have about using hydroxyurea for children, Schieve said that "there have been concerns about the treatment in terms of the potential for cancer, but there are now many, many years of study of this medication and there has never been evidence showing that it causes cancer, especially at the doses used to treat sickle cell anemia. Also, it's important to note that even though the medication has been more recently recommended for use in children, it has been safely used in adults with sickle cell anemia since the 1980s."

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