Stroke is among the main causes of death in the world, a fact that is no different in Brazil. It is grouped in diseases of the circulatory system that correspond to almost 30% of deaths in Brazil; in this group of diseases, ischemic heart diseases hold first place, immediately followed by cerebrovascular diseases.¹

It is impossible not to mention the fact that stroke, when it does not lead to death, generates disabilities and different degrees of deficiency, maintaining survival, but generating a great reduction in quality of life, in addition to inability to work and reduced autonomy with limitations in carrying out daily tasks.²

Studying the role of this group of diseases in the Southeast Region of Brazil is of great importance. Despite not being the Brazilian macro-region with the largest territorial extension, the Southeast concentrates the greatest economic activities, the largest proportion of gross domestic product, and the largest populations in relation to the other four Brazilian macro-regions.³

Some particularities of the analyzed article⁴ warrant discussion, first in relation to the restriction of the analysis to the Southeast Region of Brazil and second to using the Hospital Information System of the Unified Health System (SIH/SUS) as a source of data collection.⁵ The SIH/SUS, although very comprehensive, does not include all the information on hospitalizations due to stroke. In Brazil, the supplementary private health system has a population coverage of just over 20%. However, in the Southeast Region, private health services are responsible for the care of a larger number of people, especially in the state of São Paulo, where insurance coverage and private health plans reach close to 40%.⁶ Therefore, it is necessary to point out that this article is based on data from the SUS, which is already expressed in the title of the publication.

A criticism of the study by Reis and Chaoubah⁴ is related to the fact that it uses only code I64 of the 10th Revision of the International Classification of Diseases (ICD-10) to classify as stroke.⁷ This practice was justified in the methods, but, in our analysis, it generates an underestimation of the real number of cerebrovascular events, as it leaves out important codes that are widely used in the daily life of hospital units when filling out SIH/SUS hospitalization forms; for example, code I63, which was left out, corresponds to cerebral infarction.

Population aging clearly increases the incidence and prevalence of chronic noncommunicable diseases, such as stroke.¹ The article under analysis presents its results by age group. However, we are curious to see the behavior of the rates presented with adjustment for age, removing the effect of aging and thus verifying how the rates would be standardized by age.

The analyzed article should be valued, as it studies databases with thousands of occurrences. It generates new information of significant importance for one of the leading causes of death and disability in the world today. The authors offer a clear, objective, and well-written discussion of the analysis of their findings. Finally, it contributes to the understanding of the occurrence, over the years, of cerebrovascular disease in the most populous Brazilian region.