But the news is not all positive. Mortality rates still jumped markedly as patients transitioned from pediatric to adult care, lead author Kristine A. Karkoska, MD, a pediatric hematology/oncologist with the University of Cincinnati College of Medicine, said at the annual meeting of the American Society of Hematology.
“This reflects that young adults are getting lost to care, and then they’re presenting with acute, life-threatening complications,” she said. “We still need more emphasis on comprehensive lifetime sickle-cell care and the transition to adult clinics to improve mortality in young adults.”
According to Dr. Karkoska, researchers launched the analysis of sickle-cell mortality rates to update previously available data up to the year 2009, which showed improvements as current standard-of-care treatments were introduced. Updated numbers, she said, would reflect the influence of a rise in dedicated SCD clinics and a 2014 National Heart, Lung, and Blood Institute recommendation that all children with SCD be treated with hydroxyurea starting at 9 months.
For the study, Dr. Karkoska and colleagues analyzed mortality statistics from the period of 1979-2020 via a CDC database. They found that 5272 Black patients died of SCD from 2010 to 2020. The crude mortality rate was 1.1 per 100,000 Black people, lower than the 1.2 per 100,000 rate of 1999-2009 (P < .0001).
The researchers also found that from 2010 to 2020, the mortality rate jumped for patients in the 15-19 to 20-24 age group: It rose from 0.9 per 100,000 to 1.4 per 100,000, P < .0001).
The researchers also examined contributors to death other than SCD. In 39% of cases, underlying causes were noted: cardiovascular disease (28%), accidents (7%), cerebrovascular disease (7%), malignancy (6%), septicemia (4.8%), and renal disease (3.8%). The population of people with SCD is “getting older, and they’re developing a combination of both sickle-related chronic organ damage as well as non-sickle-related chronic disease,” Dr. Karkoska said.
She noted that limitations include a reliance on data that can be incomplete or inaccurate. She also mentioned that the study only focuses on Black patients, who make up the vast majority of those with SCD.
How good is the news about improved mortality numbers? One member of the audience at the ASH presentation was disappointed that they hadn’t gotten even better. “I was hoping to come here to be cheered up,” he said, “and I’m not.”
Three physicians who didn’t take part in the research but are familiar with the new study spoke in interviews about the findings.
Michael Bender, MD, PhD, director of the Odessa Brown Comprehensive Sickle Cell Clinic in Seattle, pointed out that mortality rates improve slowly over time, as new treatments enter the picture. When new therapies come along, he said, “it’s tough if someone’s already 40 years old and their body has gone through a lot. They’re not going to have as much benefit as someone who started [on therapy] when they were 5 years old, and they grew up with that improvement.”
Sickle cell specialist Asmaa Ferdjallah, MD, MPH, of the Mayo Clinic in Rochester, Minnesota, said that the data showing a spike in mortality rates during the pediatric-adult transition are not surprising but still “really hard to digest.”
“It is a testament to the fact that we are not meeting patients where they are,” she said. “We struggle immensely with the transition period. This is something that is difficult across all providers all over the country,” she said. “There are different ways to ensure a successful transition from the pediatric side to the adult side. Here at Mayo Clinic, we use a slow transition, and we rotate appointments with peds and adults until age 30.”
Sophie Miriam Lanzkron, MD, MHS, director of the Sickle Cell Center for Adults at Johns Hopkins Hospital, Baltimore, said increases in mortality in the post-pediatric period appear to be due in part to “lack of access to high-quality sickle cell care for adults because there aren’t enough hematologists.” Worsening disease due to aging is another factor, she said, and “there might also be some behavioral changes. Young people think they will live forever. Sometimes they choose not to adhere to medical recommendations, which for this population is very risky.”
Dr. Lanzkron said her team is developing a long-term patient registry that should provide more insight.
No study funding was reported. Dr. Karkoska had no disclosures. The other coauthor disclosed research funding and safety advisory board relationships with Novartis. Dr. Ferdjallah, Dr. Lanzkron, and Dr. Bender reported no disclosures.