Characteristics of PNH patients.

Introduction
Few studies have reported the profile of patients with paroxysmal nocturnal hemoglobinuria (PNH) and their care in the Brazilian health system.
Objective
To describe clinical and epidemiological characteristics of patients with PNH in the Brazilian public health system including procedures performed, associated comorbidities and visits to health care professionals.
Methods
In a real-world observational, retrospective, population-based cohort study, anonymized secondary data provided by the Department of Informatics of the Brazilian Unified Health System (DATASUS) were analyzed. Patients were considered eligible if they had at least one procedure coded with the ICD-10 code D59.5 from January 1, 2008 to December 30, 2018.
Results
In total, 675 individual PNH patients were identified (52.4% female; prevalence of 1:237,000 people). Around 15.8% of the patients included had myelodysplastic syndrome and about half of the sample had other aplastic anemias and/or other bone marrow failure syndromes. Portal vein thrombosis (I82 ICD code) was reported in 4.3% of patients. Regarding hospitalizations, 263 individual PNH patients had 416 inpatient admissions with the ICD code for PNH (D59.5) on admission. Twelve deaths occurred during the study period, of which two had the PNH ICD code related with the cause of death, while another three deaths were associated with acquired hemolytic anemia (D59.9), unspecified aplastic anemia (D61.9) and acute respiratory failure (J96.0), respectively.
Conclusion
Despite its limitations, this statistical analysis of data extracted from DATASUS reasonably describes PNH patients in Brazil and its variations across different regions of the country. Comorbidities frequently associated with PNH such as portal vein thrombosis were not as common in our study, but it is assumed that several thrombotic events at specific sites were coded under the broader I82 ICD code. The frequency of visits to different health professionals, including hematologists, increased after the diagnosis of PNH. Among hospitalized PNH patients, the mortality rate was 4.5%.