Abstract C09: Socioeconomic disparities in hospital admission patterns following cancer-related ED visits in the United States
Authors: Kowalkowski Marc , Raghavan Derek , Runyon Michael , Wheeler Mellisa , Gibbs Michael , Bouronich Andrea , Farhangfar Carol 
Published: May 2016

Abstract
Background: Emergency departments (EDs) evaluate and manage cancer patients with a variety of conditions (e.g., cancer-related symptoms, treatment complications). EDs provide appropriate care for acute management but utilization may reflect problems in cancer care and does not represent the optimal care setting for cancer patients. Insurance status has been shown to impact ED presentation. Yet, little is known about the impact of socioeconomic factors on hospital admission of cancer patients presenting to EDs. Identifying factors associated with admission of cancer patients from the ED may provide insight into methods to improve cancer care and reduce ED utilization.
Methods: A retrospective study of cancer-related ED visits in the US in 2012 was conducted using the Nationwide Emergency Department Sample. Cancer-related ED visits among adults over age 18 were identified by cancer-specific Clinical Classification Software codes (11-45) in the first five diagnostic positions. Care acuity was defined by Current Procedural Terminology codes for physician level of service (low=99281-99282, moderate=99283-99284, high=99285, 99291). Patients who were transferred, died in the ED, or discharged to an unknown destination (total &lt;3%) were excluded. Weighted multivariate logistic regression was performed to analyze the association between insurance status, income quartile, location and hospital admission.
Results: There were 3,019,119 cancer-related ED visits in the US in 2012 (3% of all adult ED visits). Patients with cancer-related ED visits were 69% publicly insured (57% Medicare [MC], 12% Medicaid [MA]), 23% privately insured (PI), and 5% uninsured (UN). Breast (15%), lung (14%), prostate (10%), and colon (8%) cancers were most common. Reasons for ED visits included respiratory (36%), gastrointestinal (36%), genitourinary (28%), and fluid or electrolyte (20%) problems, pain (15%), and fatigue, fever, neutropenia, and sepsis (3-5% each). Fewer UN (15%), MA (17%), and PI (18%) patients were coded as high acuity, compared to MC (21%; p&lt;.001). 50% of cancer-related ED visits resulted in admission to the same hospital, compared to 17% of all adult ED visits (p&lt;.001). In multivariate analysis adjusted for age, gender, cancer type, presenting conditions, acuity, location of patient's residence, admission timing (weekday/weekend), hospital region, and teaching status, the odds of admission following ED presentation were lower for UN (odds ratio [OR]=0.67; 95% confidence interval [CI]=0.48-0.93) and MA (OR=0.87; 95%CI=0.77-0.98) and higher for PI (OR=1.16; 95%CI=1.06-1.26) patients, compared to MC patients. The odds of admission were also lower for residents of non-large metro areas (OR=0.31; 95%CI=0.21-0.44), compared to large metro, and in Midwest (OR=0.14; 95%CI=0.09-0.21) and West (OR=0.15; 95%CI=0.09-0.24) region hospitals, compared to South, and higher with older age (OR=1.22; 95%CI=1.16-1.27) and for patients with metastatic disease (OR=6.89; 95%CI=5.98-7.94), neutropenia (OR=7.93; 95%CI=6.22-10.12), or fluid or electrolyte problems (OR=5.97; 95%CI=5.46-6.53). There was no difference in admission odds by income quartile.
Conclusion: Lower odds of admission following cancer-related ED visits were associated with non-clinical factors (UN/MA patients, non-large metro location, Midwest/West region). Clinical elements (older age, metastases, neutropenia, fluid or electrolyte problems) were important correlates of admission but only partly explained differences by insurance, location, and region. Additional research will seek to identify potential causes of decreased admission among UN and MA patients, including the roles of source of care, different acuity levels, and undesirable financial liability associated with inpatient management, to evaluate the rate of ED readmission after discharge, and to determine factors contributing to lower admission rates in the Midwest and West regions.
Citation Format: Marc Kowalkowski, Derek Raghavan, Michael Runyon, Mellisa Wheeler, Michael Gibbs, Andrea Bouronich, Carol Farhangfar. Socioeconomic disparities in hospital admission patterns following cancer-related ED visits in the United States. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C09.