Sepsis in Patients Receiving Immunosuppressive Drugs in Korea: Analysis of the National Insurance Database from 2009 to 2013

Background: The aim of this study is to evaluate the influence of immunosuppressants on in-hospital mortality from sepsis. Methods: Using data of the Health Insurance Review & Assessment Service, we collected data from patients who were admitted to the hospital due to sepsis from 2009 to 2013. Based on drugs commonly used for immunosuppression caused by various diseases, patients were divided into three groups; immunosuppressant group, steroid-only group, and control group. Patients with no history of immunosuppressants or steroids were assigned to the control group. To identify risk factors of in-hospital mortality in sepsis, we compared differences in patient characteristics, comorbidities, intensive care unit (ICU) care requirements, and immunodeficiency profiles. Subgroup analysis according to age was also performed. Results: Of the 185,671 included patients, 13,935 (7.5%) were in the steroid-only group and 2,771 patients (1.5%) were in the immunosuppressant group. The overall in-hospital mortality was 38.9% and showed an increasing trend with age. The steroid-only group showed the lowest in-hospital mortality among the three groups except the patients younger than 30 years. The steroid-only group and immunosuppressant group received ICU treatment more frequently (p < 0.001), stayed longer in the hospital (p < 0.001), and showed higher medical expenditure (p < 0.001) compared to the normal group. Univariate and multivariate analyses revealed that age, male gender, comorbidities (especially malignancy), and ICU treatment had a significant effect on in-hospital mortality. Conclusions: Despite longer hospital length of stay and more frequent need for ICU care, the in-hospital mortality was lower in patients taking immunosuppressive drugs than in patients not taking immunosuppressive drugs.