Types of cancer and outcomes in patients with cancer requiring admission from the emergency department: A nationwide, population-based study, 2016-2017.

BACKGROUND Emergency department (ED) utilization and emergency admissions by patients with cancer have increased. The authors aimed to evaluate the characteristics of patients with cancer admitted through the ED and determine whether cancer types are related to in-hospital mortality. METHODS The National Emergency Department Information System database of patients visiting EDs in South Korea between 2016 and 2017 was analyzed. Among 6,179,088 adult patients who presented to an ED with nontraumatic medical illness, patients with cancer were identified. The primary outcome was in-hospital mortality. RESULTS Patients with cancer accounted for 6.8% of ED visits, and 239,630 patients (57.0%) were admitted to the hospital (intensive care unit [ICU], 9.5%; others, 90.5%). The prevalent cancers requiring hospitalization were lung cancer (15.7%), liver cancer (14.2%), and colon cancer (11.6%). The commonest reasons for admission other than cancer-related medical problems (41.4%) were pneumonia (4.8%) and hepatobiliary infection (2.8%). Overall in-hospital mortality was 16.1% (ICU, 28.3%; general wards, 14.8%); lung cancer (22.9%), liver cancer (19.7%), and leukemia/multiple myeloma (17.8%) showed the highest mortality rates. The highest odds for mortality were for lung cancer (adjusted odds ratio [OR], 2.227; 95% confidence interval [CI], 2.124-2.335; P < .001) and liver cancer (adjusted OR, 1.839; 95% CI, 1.751-1.930; P < .001), which were referenced to genitourinary cancer by multivariable logistic regression analysis. CONCLUSIONS More than half of the patients with cancer visiting EDs were admitted to the hospital with a mortality rate of 16.1%. Physicians treating patients with cancer and policymakers and planners designing health systems should understand the different prevalences and outcomes of oncological emergencies by cancer type to improve patient care.