Cystic Fibrosis: A Descriptive Analysis of Deaths in a Two-Decade Period in Brazil According to Age, Race, and Sex

Abstract

The diagnosis of cystic fibrosis has improved in the last few years due to greater access to diagnostic tools and the evolution of molecular biology; the knowledge obtained has contributed to the understanding of its death profile. In this context, an epidemiological study was developed focusing on deaths from cystic fibrosis in Brazil from 1996 to 2019. The data were collected from the Data-SUS (Unified National Health System Information Technology Department from Brazil). The epidemiological analysis included patients' age groups, racial groups, and sex. In our data, between 1996 and 2019, Σ3050 deaths were recorded, totaling a ≅330% increase in the number of deaths resulting from cystic fibrosis. This fact might be related to a better diagnosis of the disease, mainly in patients from racial groups that are not commonly associated with cystic fibrosis, such as Black individuals, Hispanic or Latino (mixed individuals/Pardos) individuals, and American Indians (Indigenous peoples from Brazil). Regarding of race, the Σ of deaths was: nine (0.3%) in the American Indian group, 12 (0.4%) in the Asian group, 99 (3.6%) in the Black or African American group, 787 (28.6%) in the Hispanic or Latino group, and 1843 (67.0%) in the White group. The White group showed the highest prevalence of deaths, and the increase in mortality was ≅150 times in this group, while, in the Hispanic or Latino group, it was ≅75 times. Regarding sex, the numbers and percentage of deaths of both male (N = 1492; 48.9%) and female (N = 1557; 51.1%) patients were seen to be relatively close. As for age groups, the >60-year-old group presented the most significant results, with an increase of ≅60 times in the registered deaths. In conclusion, in Brazil, despite the number of deaths from cystic fibrosis being prevalent in the White group, it increased in all racial groups (Hispanic or Latino, Black or African American, American Indian, or Asian individuals) and was associated with older age.

Keywords: CFTR; diagnosis; distribution per race; epidemiology; genetic screening; human development index; neonatal screening; sweat test.

Figure 1

Number of deaths from cystic fibrosis (CF) in Brazil from 1996 to 2019 according to the Brazilian region (Figure 1A) and racial group (Figure 1B). (A) In 1996, the Southeast (the most populated Brazilian region) presented 31 reported deaths from CF. In 2019, the number increased from 31 to 112 cases, totaling 1418 deaths, with an increase of 3.6 times. The South region presented 13 deaths in 1996. This number rose to 47 in 2019, representing an increase of 3.6 times and totaling 604 deaths. The Northeast region had nine deaths in 1996, rising to 49 in 2019, demonstrating an increase of 5.4 times and 597 deaths. Finally, in 1996, the North region presented two deaths from CF, while the Midwest had three, which increased to 24 and 16, respectively, in 2019. This shows a 12-fold increase, totaling 228 deaths in the North region, while the Midwest region presented a 5.3-fold increase and 203 deaths. (B) Only one death from CF in the White group was recorded in 1996. In 2019, however, this number increased to 148. During this period, 1843 deaths were reported. No Hispanic or Latino, Black or African American, American Indian, or Asian individual died due to CF in 1996. On the other hand, in 2019, 80 deaths were reported in the Hispanic or Latino racial group, totaling 787 cases in the period analyzed; 12 in the Black or African American group, reaching 99 deaths; three in the American Indian group, totaling nine cases, and one in the Asian group, totaling 12 deaths. In addition to these cases, the Data-SUS death registers recorded deaths under the classification ‘not informed’. Within that group, 57 cases were reported in 1996 and only four cases in 2019, totaling 300 occurrences.

Figure 2

Number of deaths from cystic fibrosis (CF) in Brazil from 1996 to 2019 according to age group (Figure 2A) and relative percentage of deaths (Figure 2B). (A) The <4-year-old age group presented 27 cases in 1996 and 31 cases in 2019, resulting in 674 (22.1%) deaths from CF in the period analyzed. The age group from five to 19 years old presented 19 deaths in 1996 and 36 deaths in 2019, totaling 667 (21.9%) deaths from CF. The age group from 20 to 59 years old resulted in eight cases in 1996 and 63 deaths in 2019, resulting in 757 (24.8%) occurrences. Finally, the >60-year-old age group had two cases in 1996 and 118 cases in 2019, totaling 950 (31.2%) deaths from CF during the study period. (B) Considering all the age groups presented in the study, the >60-year-old age group showed steady growth over the years. Such a result suggests that CF management has contributed to longer life expectancy. yo, years old; %, percentage.

Figure 3

Mortality due to cystic fibrosis in Brazil from 1996 to 2019 according to sex (Figure 3A) and relative percentage of deaths (Figure 3B). (A) In 1996, 25 deaths of male patients and 33 deaths of female patients were reported, while, in 2019, the deaths reported involved 128 male patients and 120 female patients, totaling 1492 (48.9%) and 1557 (51.1%) deaths, respectively, in the study period. (B) The percentage of deaths in each sex group was similar, without significant discrepancy, in disagreement with the information found in the literature, in which the female sex is associated with higher mortality rates. %, percentage.

Figure 4

Correlation between the number of deaths from cystic fibrosis (CF) in the 2017–2019 period and the Human Development Index [HDI, HDI—education (HDI-E), HDI—gross national index (HDI-GNI), and HDI—life expectancy (HDI-LE)]; and between the number of deaths from CF in the 1996–2019 period and HDI, HDI-E, HDI-GNI, and HDI-LE. The Spearman correlations considered the following cut-off points: (i) ±0.90–1.0, very high positive–negative correlation index; (ii) ±0.70–0.90, high positive–negative correlation index; (iii) ±0.50–0.70, moderate positive–negative correlation index; (iv) ±0.30–0.50 low positive–negative correlation index; and (v) 0.00–0.30, insignificant positive–negative correlation index. An alpha error of 0.05 was used in the statistical analysis. %, percentage.