Blood transfusions per hospitalization in the local public health network of Belo Horizonte between 2008 and 2021: A time series analysis

Background: Blood transfusion rates are increasing worldwide. This work was a longitudinal retrospective study conducted with data referent to the use of blood components between January 2008 and December 2021 in the local public health network of Belo Horizonte, Minas Gerais, at Hospital Risoleta Tolentino Neves (HRTN), Hospital Metropolitano Dr. Célio de Castro (HMDCC), and Hospital Metropolitano Odilon Behrens (HMOB). Objective: This study sought to describe the time series of the number of blood transfusions and blood transfusion rates per general hospitalization through a time series analysis. Methods: Through data from the Hospital Information System of the Unified Health System (HIS-SUS), this study formulated six monthly time series of the number of blood transfusions and blood transfusion rates per hospitalization. The stationarity, trend, and seasonality of the time series were verified by the unit root test, using the Mann-Kendall and the Fisher tests, respectively. The normality hypothesis of the data was verified by the Shapiro-Wilk test. All of the statistical tests considered a significance level of 5%. Results: The average monthly blood transfusion rates per hospitalization observed in this study were 45.5%, 26.9%, and 26.3% at HRTN, HMDCC, and HMOB, respectively. The highest decrease in the number of blood transfusions was observed at HMDCC and the highest decrease in blood transfusion rates was observed at HRTN. Packed red blood cells were the most commonly used blood component at HRTN, HMOB, and HMDCC (54.6%, 58.3%, and 65.4%, respectively). The time series showed that they were non-stationary, with a downward trend and the presence of a 12-month seasonal component. Conclusion: The decline in the number of blood transfusions should be considered a positive phenomenon in public health due to best use and quality management, since a decrease in blood donation rates was also observed.