Differences between Chest Pain Observation Service Patients and Admitted “Rule‐out Myocardial Infarction” Patients

Abstract
To compare and contrast the patient characteristics of ED patients at low risk for acute cardiac ischemia who were assigned to a chest pain observation service vs those admitted to a monitored inpatient bed for "rule-out acute myocardial infarction" (R/O MI). This was a retrospective, cross-sectional comparison of adult patients considered at relatively low risk for cardiac ischemia and who were evaluated in 1 of 2 settings: a short-term observation service and an inpatient monitored bed. All patients had an ED final diagnosis of "chest pain," "R/O MI," or "unstable angina" during the 7-month study period. Demographic features and presenting clinical features were examined as a function of site of patient evaluation. Of 531 study patients, 265 (50%) were assigned to the observation service. Younger age (OR = 1.75, 95% CI 1.26, 2.44, for each decrement of 20 years), the complaint of "chest pain" (OR = 2.35, 95% CI 1.34, 4.12), and the absence of prior known coronary artery disease (OR = 1.64, 95% CI 1.13, 2.38) were the principal independent factors associated with assignment to a chest pain observation service bed. Patients evaluated in a chest pain observation service appear to have different clinical characteristics than other individuals admitted to a monitored inpatient bed for "R/O MI." Investigators should address differences in clinical characteristics when making outcome comparisons between these 2 patient groups.