Influenza as an important factor causing increased risk of patients' deaths, excessive morbidity and prolonged hospital stays

Abstract

Introduction: Influenza infection is associated with potential serious complications, increased hospitalization rates and a higher risk of death.

Material and methods: A retrospective comparative analysis of selected indicators of hospitalization at the University Hospital in Wroclaw was conducted on patients with confirmed influenza infection and a control group during the 2018-2019 influenza season. The threshold for statistical significance of differences between the groups was set at p < 0.05.

Results: The types of influenza viruses confirmed in the hospital patients were remarkably similar to those occurring in the general population in Poland. The largest numbers of influenza cases were observed at the departments related to internal medicine where patients with cardiac, lung and renal diseases were hospitalized. The risk of death among the patients with confirmed influenza infection was significantly higher than among the other patients. The highest risk of death was observed among the patients with confirmed influenza infection at the departments related to internal medicine. Considering patients from the entire hospital, the mean length of hospital stay for those with confirmed influenza was 2.13-fold longer than for those in the control group. Comparisons of the median, minimum and maximum lengths of hospitalization between the patients with confirmed influenza infection and the control group reveal even more distinct differences.

Conclusions: Significant differences in the selected indicators of hospitalization were observed between the patients with confirmed influenza infection and the control group; they are associated with serious social costs, such as prolonged hospital stay and a higher risk of death during hospitalization in Poland.

Keywords: aged; hospital economics; human influenza; influenza vaccines; length of stay; medical economics; morbidity; mortality; multimorbidity.

Figure 1

Numbers of patients with confirmed influenza and numbers of deceased patients with confirmed influenza infection, by department

Figure 2

Mean ages of patients with confirmed influenza infection and the control group, by department

Figure 3

Mean lengths of stay in hospital department for patients with confirmed influenza infection and for the control group

Figure 4

Mean lengths of stay in hospital departments (with statistically significant differences between groups) for patients with confirmed influenza infection and for the control group

Figure 5

Mean lengths of overall hospital stay for patients with confirmed influenza infection and for the control group

Figure 6

Mean lengths of overall hospital stay for patients with confirmed influenza infection and for the control group (departments with statistically significant differences between groups)