National Analysis of Preexisting Immunosuppressive Conditions and Infection-Related Readmissions Among Sepsis Survivors.

Background: Recurrent episodes of infection and subsequent sepsis are a frequent cause of readmission after sepsis hospitalization. Although persistent immune dysregulation initiated during the sepsis episode may play a role, the impact of preexisting immune suppression (including HIV, organ transplantation, and cancer) and common chronic diseases associated with immune suppression (diabetes and chronic kidney disease) on the risk of recurrent infections after sepsis is unknown.

Objectives: To investigate the role of preexisting immune-suppressive conditions (PISCs) and other common chronic diseases on infection-related readmissions after a sepsis admission.

Methods: Using the US 2015 Nationwide Readmissions Database, we identified a retrospective cohort of adult patients with an unplanned sepsis index admission from April to September, excluding patients with sepsis during the preceding 90 days. We followed all sepsis survivors for subsequent infection-related admissions for 90 days. We identified clinical conditions using International Classification of Diseases coding.

Results: We identified 649 029 unique unplanned sepsis admissions over 6 months; 189 604 (29.2%) had sepsis with PISC, and 459 425 (70.8%) had sepsis without PISC. Overall, sepsis survivors were older (median age, 70 years), and 145 156 (22.4%) experienced at least 1 infection-related readmission within 90 days. The incidence of infection-related readmission among sepsis survivors with PISC was 26.1%, whereas it was 20.8% for those without PISC. The excess risk of infection-related readmissions attributed to PISC was 5.3%, whereas the excess risk attributed to diabetes and chronic kidney disease was 3.7% and 4.7%, respectively. The background risk attributed to new-onset sepsis among participants with none of these conditions was 16.3%. Multivariable regression analysis adjusting for age, gender, and acute illness factors indicated that odds of infection-related readmission were strongly associated with PISC (odds ratio 1.30; 95% confidence interval, 1.29-1.32), closely followed by chronic kidney disease (1.28 [1.27-1.32]) and diabetes (1.17 [1.16-1.19]).

Conclusion: The risk of subsequent infection is higher among patients with PISC, although chronic kidney disease and diabetes are also important risk factors for subsequent infection and sepsis readmissions.