Individuals with these two genetic conditions are seeing increased, but unequal, life expectancies

New research from the Arnold School’s Department of Epidemiology and Biostatistics has found disparities in mortality rates and life expectancy for Americans living with sickle cell disease or cystic fibrosis. The study, which was led by third-year doctoral student Hiluf Abraha and published in JAMA Pediatrics (the highest-ranked journal in the field), found that despite medical advances in the treatment of both conditions, individuals with sickle cell disease have experienced more modest gains in life expectancy compared to those with cystic fibrosis. Further, they are facing increased mortality rates, while deaths in the cystic fibrosis population have declined.

“This study highlights a significant disparity in mortality between individuals with sickle cell disease and those with cystic fibrosis,” Abraha says. “Several factors contribute to this stagnation, including under resourced care systems, limited access to first-line therapies and challenges with new therapies, such as cost and access.”

Approximately 100,000 individuals, primarily Black, are living with sickle cell disease in the U.S. while cystic fibrosis affects around 35,000, predominantly white individuals. Given the significant advances in therapeutics and improved care over the last two decades, particularly for cystic fibrosis, the researchers examined data over a 15-year period (2008 – 2023) from the National Center for Health Statistics.

Their analysis revealed 15,242 deaths attributable to sickle cell disease and 7,451 to cystic fibrosis. The life expectancy for the first group rose from 40 to 46 during this time period while the second group increased from 31 to 48. However, cystic fibrosis mortality declined steadily across all age groups and saw a rise only among those ages 65 and older, reflecting increased longevity. Meanwhile, sickle cell disease mortality increased across most age groups, except for individuals ages 0 to 24.

As part of the effort to close these gaps and improve outcomes for individuals with sickle cell disease, the authors recommend decoupling financial incentives from patient costs by leveraging federally funded programs to increase access to effective therapies.

“Initiatives such as the Centers for Medicare & Medicaid Services’ cell and gene therapy access model could improve access for Medicaid beneficiaries with sickle cell disease, for example,” Abraha says. “Medicaid expansion is another crucial approach to ensuring access to these treatments.”

A midwife by training, Abraha built on his clinical experience by earning a master’s in biostatistics and health informatics and working in the areas of health care systems and data management at hospitals and clinical settings in Ethiopia. With a continued passion for maternal and child health, he enrolled in the Arnold School’s Ph.D. in Epidemiology program in 2023 and began conducting research alongside associate professor Nansi Boghossian, who is a senior author on the study.

Abraha is a Norman J. Arnold Doctoral Fellow, a Grace Jordan McFadden Professors Program Scholar, and a Junior Scholar with the South Carolina SmartState Center for Healthcare Quality.