ECMO is increasingly used for patients with critical illnesses. This study examines the impact of ECMO use on mortality, hospital length of stay, and total hospital charges for patients with cardiogenic shock in US hospitals using the National Emergency Department Sample 2013 dataset.
NEDS combines both clinical and non-clinical variables from both national and state sources, specifically 947 hospitals that represent a 20% stratified sample of hospital-based EDs across 30 participating states in the US. HCUP recommendations and instructions were followed for data weighting using the following stratification variables: US Census region, urban-rural location, ownership, and teaching status of the hospital and trauma center designation.
A group of patients with cardiogenic shock and reported ECMO use were randomly matched (1:1) with another group with cardiogenic shock without ECMO use. The following variables were used for matching: age (match tolerance = 2), sex, season of admission, whether admission day is a weekday or a weekend, presence of chronic conditions, Injury Severity Score (match tolerance = 1), primary expected payer, median household income, hospital urban/rural designation, and the four categories of procedure class (minor diagnostic, minor therapeutic, major diagnostic, major therapeutic).
The following CCS codes were adopted from Maxwell et al. to select those presenting with cardiogenic shock: CCS 97, CCS 100, CCS 101, CCS 103, CCS 106, CCS 107, CCS 108.
ECMO use was selected using the ICD-9-CM 3965 procedure code.
All patients with the appropriate CCS and ICD-9 codes were included
Patients who were routinely discharged, transferred, discharged to home health care, discharged against medical advice, or whose destination was unknown were excluded from the study.