Regional incidence of venous thromboembolism in Brazil

Abstract

Background

Several studies conducted in areas with temperate climates have suggested that the incidence of venous thromboembolism (VTE) varies depending on seasonal climatic fluctuations. However, no studies have been conducted comparing areas with semi-arid climate with areas with temperate climates.

Objectives

To analyze whether there is a correlation between the incidence of VTE in areas with semi-arid climates and areas with temperate climates in Brazil.

Methods

Retrospective data were acquired for patients diagnosed with VTE from January 2011 to December 2014 from the Brazilian National Health Service for the following Brazilian states that have semi-arid climates: Alagoas, Ceará, Maranhão, Paraíba, Pernambuco, Piauí, and Rio Grande do Norte (all located in the Northeast Region of Brazil); and the following states with temperate climates: Paraná, Santa Catarina, and Rio Grande do Sul (all located in the South Region of Brazil). Data on climatic variation were obtained from the National Meteorological Institute and population data were obtained from the Brazilian Institute of Geography and Statistics.

Results

There was a significant correlation in the incidence of VTE cases in areas with lower temperatures (p < 0.001). The South Region exhibited significantly lower temperatures than the Northeast Region (p < 0.001) and had a significantly higher number of cases of VTE than the Northeast Region (p < 0.001).

Conclusions

There are more cases of VTE in areas with temperate climates, where temperatures are lower. However, there is still little information in the literature on seasonal fluctuations and incidence of VTE. More studies of this subject are needed.

Keywords:
venous thromboembolism; venous thrombosis; seasonality; climate