Patients with sickle cell disease (SCD) tend to have inferior survival compared to the general population, according to the first periodic life table for SCD based on actual population data. Study findings, which were published in Blood Advances, also show that patients with SCD who qualify for certain types of public insurance tend to have lower life expectancies than those on other types of public insurance.
“Our study indicates that individuals with [SCD] continue to experience a life expectancy shortfall, despite being covered by public insurance,” said lead co-author Boshen Jiao, MPH, PhD, a post-doctoral research fellow at the Harvard T.H. Chan School of Public Health, who conducted the research while at the University of Washington Comparative Health Outcomes, Policy, and Economics Institute. “This highlights the need for innovative curative or disease-modifying therapies that can offer greater survival benefits to these patients.”
A previous study projected a much shorter life expectancy for people with SCD, but it was conducted using a simulation model with statistics summaries and did not include estimations based on individual data points. Most people with SCD are on public insurance, but other studies using Medicare or Medicaid data have been limited to a few states or to hospital settings.
For the present study, Dr. Jiao and colleagues pulled data from the Medicaid Analytic eXtract files, as well as Medicare Part A and B fee-for-service claims from 2008 to 2016. These data encompass all claims for people with SCD who are covered by Medicaid or Medicare in all 50 states. Researchers obtained dates of death from death certificates through the National Death Index. The study did not include those who received hematopoietic cell transplantation.
Researchers found that at birth, the overall life expectancy for a person with SCD, regardless of insurance type, was 52.6 years to 55.0 years for women and 49.3 years for men. Previous studies have shown that the life expectancy for a non-SCD population matched by age, sex, and race or ethnicity was 76 years, indicating a huge gap in years lived for those with SCD.
Researchers found that the life expectancy at 65 years old for those on Medicare old age or survivor insurance was 15.2 years, while the age 65 life expectancy for those on Medicare disability insurance benefits or for end-stage renal disease was 11.2 years. Those dually eligible for both Medicare and Medicaid had an age 65 life expectancy of 12.1 years, the researchers found.
Overall, the survivability of younger people with SCD was high – the survival probability at 18 years old was 0.98. However, after the transition to adulthood, survival probability fell rapidly, researchers found. The survival probability at age 30 was 0.804; at 45, 0.628; at 65, 0.267; and at 85, 0.070.
“This is in line with the general understanding that survivorship into adulthood for children with [SCD] has improved, but early mortality among adults is still a major concern,” Dr. Jiao said. “Our findings underscore the importance of health care during the transition period from childhood to adulthood for [patients with SCD]. Furthermore, the development of a curative therapy that can intervene during the early stages of life course, prior to adulthood, would be highly desirable.”
The study, he said, was not intended as an assessment of insurance quality. The findings “reflect more on the differences in comorbidity mix and severity of [SCD] in the population enrolled in those insurances, rather than insurance ‘causing’ these differences,” he added.
The study didn’t investigate the disparities in outcomes by insurance type, Dr. Jiao said, adding, “Our other work reveals that much of these differences can be attributed to the differences in comorbidity mix and severity of [SCD] in the population enrolled in those insurances. We recommend future research to further identify the mechanisms underlying these disparities.”
Any conflicts of interest declared by the authors can be found in the original article.
Reference
Jiao B, Johnson K, Ramsey S, Bender M, Devine B, Basu A. Long-term survival with sickle cell disease: a nationwide cohort study of Medicare and Medicaid beneficiaries [published online, 2023 Mar 16]. Blood Adv. doi: 10.1182/bloodadvances.2022009202.
