SCD reduces life expectancy in Brazil by 32 years: Real-world study

Researchers call for more patient access to adequate healthcare

Andrea Lobo, PhD avatar

by Andrea Lobo, PhD |

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Despite improvements in newborn screening for sickle cell disease (SCD) in Brazil, the mortality rate for children and young adults with the disease remains high, according to a recent study that highlights the burden of the disease and the need for improved healthcare for these patients.

Researchers found that the disease was associated with a 32-times higher risk of death among children, and with a 13-times higher risk of death among young adults. Findings also indicated that SCD led to an estimated loss of 32 years of life over a person’s lifetime.

“The most common causes of death were sepsis and respiratory failure,” researchers wrote.

“Mortality remains high; in the short term, providing access to known effective treatments and adequate healthcare for complications should be a major priority,” they noted.

The study, “Estimated mortality rates of individuals with sickle cell disease in Brazil: real-world evidence,” was published in the journal Blood Advances.

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Sickle cell affects 276K infants annually around the world

SCD is a life-threatening genetic disorder that affects around 276,000 infants worldwide each year. It is caused by genetic mutations that result in the production of a faulty version of hemoglobin, the oxygen-carrying protein in red blood cells, causing red blood cells to take on the characteristic sickle-like shape that gives the disease its name.

Despite advances in treatment and diagnosis, people with SCD generally have a reduced quality of life and lifespan compared with the general population. In the U.S., a study indicated that SCD patients had a lower estimated life expectancy (54 vs. 76 years) and a lower quality-adjusted life expectancy (33 vs. 67 years) compared with those without the disease.

In Brazil, SCD is estimated to affect 60,000 to 100,000 people, with an incidence of 45.92 cases per 100,000 live births reported from 2015 to 2019. Previous studies have estimated SCD is associated with a mortality rate of 0.12 to 0.54 per 100,000 people.

The disease is associated with a high burden for patients in Brazil. Factors that may contribute to a lower quality of life include the intensity and frequency of vaso-occlusive crises, the need for hospitalizations and blood transfusions, as well as the social effects associated with unemployment, low educational levels, and financial issues.

“In Brazil, these problems are magnified due to suboptimal healthcare system organization and barriers to adequate healthcare access for many patients with SCD,” the researchers wrote.

These results highlight the burden of SCD in Brazil and the necessity of improved care for this population.

Researchers analyzed 5-year real-world data from Brazilian public databases

To estimate the mortality risk for individuals with SCD compared with the general population, researchers analyzed real-world data from Brazilian public databases gathered from 2015 to 2019.

In that five-year period, a total of 6,553,132 deaths were registered in Brazil, with 3,320 (0.05%) of them being people with SCD. The median age at death for people with SCD was 32 years, while the median age at death for the general population was 69 years.

The majority of SCD patients who died from the disease were mixed race or Black (78.6%), and more than half were female (52.2%). Most deaths occurred in the southeast (44.9%) and northeast regions (34.6%) of the country, where the disease is more prevalent.

The researchers identified 2,603 people whose primary cause of death, at a median age of 30 years, was SCD.

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Median estimated survival of 40 years for SCD patient in Brazil

Over the five years analyzed, the mean crude annual mortality rate in SCD patients was 0.32 per 100,000 inhabitants, and 0.25 per 100,000 inhabitants when estimates were made taking into account only individuals whose primary cause of death was SCD.

The most common causes of death among people with SCD were sepsis (24.2%) — the body’s extreme response to an infection — and respiratory failure (7.9%).

The researchers estimated 60,017 people were living with SCD in Brazil in that period, corresponding to 29.02 cases per 100,000 inhabitants. On average, 1,362 new SCD cases were diagnosed every year from 2015 to 2019.

SCD patients had a median estimated survival of 40 years, while those without the disease had an estimated median survival of 80 years.

During childhood, the risk of death for people with SCD was more than 30-times higher compared with the general population. In adults ages 20 to 39 years, the risk of death was 13-times higher among those with SCD compared with people without the disease. In those older than 70 years, the risk of death was similar between the two groups.

Over a person’s lifetime, SCD was associated with a loss of 32 years of life.

“These results highlight the burden of SCD in Brazil and the necessity of improved care for this population,” the researchers wrote.