Short and long term impact of influenza infection on individuals with type 2 diabetes: Effect on healthcare utilization and diabetes complications

Objectives:Influenza is a common and often underestimated viral infection that has been shown to trigger severe complications in high-risk patients and can lead to loss of blood glucose control in individuals with Type 2 diabetes (T2D). However, the long-term impact of influenza on this population has not been assessed very well. This study aims to examine the long-term burden of influenza infection among those with T2D, including impact on healthcare utilization and chronic diabetes-related complications. Methods:A retrospective cohort study was conducted using US commercial claims (2015-2018). T2D patients who had experienced an influenza infection were matched 1:5 with non-infected controls. The matched cohorts were followed for one year and compared at five different time periods (four quarters of 91 days, and at full-year) by healthcare utilization, including number of outpatient, Emergency Room (ER), and inpatient hospital visits and total medical expenses. Diabetes Complications Severity Index Score (DCSI) was used to measure diabetes complications at index date and after one year. Results: A total of 7,776 T2D patients with influenza were matched with 38,880 control patients. The cohort post-influenza infection had significantly higher total medical expenses, number of ER and outpatient visits in each time period, and increased numbers of hospitalizations in time periods Q1, Q3, and full-year. The influenza cohort also had significantly higher increase in DCSI after one year. Conclusion:The results from this study suggest that an influenza infection may have a significant long-term impact on T2D patient morbidity, including worsening of diabetes. When estimating the burden of influenza on this population and making treatment decisions, both short- and long-term impact should be considered.