Deaths attributed to sarcoidosis as the primary underlying cause increased between 1999 and 2016 in the United States, according to a recent observational study.
The study, “Sarcoidosis deaths in the United States: 1999–2016,” published in the journal Respiratory Medicine, compared death rates among different regions, races, genders, and ages in the U.S.
Research on sarcoidosis has advanced, especially with more understanding of the disease’s development. Still, sarcoidosis is understudied, and little is known, for example, about its specific causes or biomarkers that can aid in clinical decision-making.
In addition, regional and population differences in incidence, prevalence, and disease course are still unclear. Although some studies have reported gender- and race-dependent differences in death rates, they have not been able to offer a clear explanation for these differences.
To better understand the disease and offer possible population-based explanations, researchers investigated mortality rate trends in sarcoidosis patients in the U.S. based on national death certificate data.
The team collected data from the period between 1999 and 2016, using the Centers for Disease Control and Prevention, Wide-ranging Online Data for Epidemiologic Research from the National Vital Statistics System, which is an online source of health statistics data.
Results showed a total of 16,665 deaths in the U.S. that listed sarcoidosis as the primary underlying cause during the period analyzed.
According to the data, the mortality rate during this period increased from 2.1 in 1999 to 3 in 2016 per 1 million people. The team observed that the rates specifically increased between 1999 and 2002 (from 2.1 to 3.1), and remained relatively stable thereafter.
Death rates were higher for patients ages 35 years or older; the highest rates were observed in the age groups 65-74 years (8.5 deaths per 1 million) and 75-84 years (9 deaths per 1 million).
During the study period, the death rate for women increased by 32% (from 2.5 to 3.3 deaths per 1 million people), while the mortality rate for men increased by 73.3% (from 1.5 to 2.6 deaths per 1 million). These analyses were age-adjusted to allow comparisons among different age groups within the population.
Researchers also found that African-Americans had the highest death rates in the population studied. African-American women had a death rate of 17 per 1 million, and African-American men a death rate of 12.4. These increases can be compared with death rates observed in Caucasian women and men, which were 1.5 and 1.2 deaths per 1 million, respectively.
Researchers also analyzed regional differences, and found the highest death rate in the Southern U.S. (3.7 deaths per 1 million).
When the team further divided the results according to region, age, and gender, they found the overall highest death rates among African-American women in the Midwest — 18.7 deaths per 1 million people.
The researchers pointed out that, although the increases in observed death rates (specifically among African-American women) are worrisome, they could also be explained by an overall increased awareness of the disease.
“The observed increase in death rates among black female sarcoidosis deaths over the study period is concerning,” the team wrote, “one suggestion may be that an increased focus and higher awareness of the disease in black females is now yielding more reported deaths on the death certificate.”
Although this type of data may cause uncertainties, the researchers emphasize the importance of studies such as this.
“Results from this project can be useful for making comparisons of mortality rates and examining demographic and geographic trends of reported sarcoidosis deaths across the U.S.,” they wrote.
“It is anticipated that this paper will spark new interest among others, particularly national funding agencies, to recognize the need for more advanced epidemiological research to examine this multifactorial, chronic health condition,” they added.