Demographic Changes in Intensive Care Units in Korea over the Last Decade and Outcomes of Elderly Patients: A Single-Center Retrospective Study

Background Aging is a significant issue worldwide, and Korea is one of the most rapidly aging countries. Along with the demographic transition, the age structure of intensive care unit (ICU) patients changes as well. Methods The aim of this study was to analyze the change in age distribution of the ICU patients over the last 10 years and its effect on clinical outcomes. Single-center, retrospective analysis of all patients aged ≥18 years admitted to either the medical or surgical ICU at St. Paul’s Hospital, The Catholic University of Korea, between January 2005 and December 2014 was conducted. For clinical outcome, in-hospital mortality, duration of ICU stay, and hospital stay were analyzed. Cost analysis was performed to show the economic burden of each age strata. Results A total of 10,366 ICU patients were admitted to the chosen ICUs during the study period. The proportion of elderly patients aged ≥65 years increased from 47.9% in 2005 to 63.7% in 2014, and the proportion of the very elderly patients aged ≥80 years increased from 12.8% to 20.7%. However, this increased proportion of elderly patients did not lead to increased in-hospital mortality. The percent of ICU treatment days attributable to elderly patients increased from 51.1% in year 2005 to 64.0% in 2014. The elderly ICU patients were associated with higher in-hospital mortality compared to younger age groups. Conclusions The proportion of elderly patients admitted to ICUs increased over the last decade. However, overall in-hospital mortality has not increased during the same period.