Here's an interesting paper on observation units (OUs).  In this study, they compare OU utilization and resulting hospital admissions between an OU that's part of the ED (an EDOU patient) and an "inhospital" OU (an IHOU).  They looked at a total of 2,594 patients presenting with chest pain, 1190 during the EDOU trial, and 1404 during the IHOU trial. During the 5 month EDOU period, 36.9% of patients presenting with chest pain were admitted for observation vs 69.3% during the IHOU period (P<.0001).  Fewer patients with chest pain were converted to full inpatient admission from the EDOU, 35 (7.9%) of 440, when compared with the IHOU, 187 (19.2%) of 973 (P<.0001).

Their conclusion is that an ED based OU is more cost-effective than one based inhospital. I would like to know a lot more of the variables before drawing that conclusion. Are both OUs staff the same? Where there any trust issues between the ED staff and IHOU? Are the OU and hospital admissions criteria the same? Was there any case manager review of the study?