Effect on efficiency and cost-effectiveness when an observation unit is managed as a closed unit vs an open unit.

Objective: To compare efficiency and cost-effectiveness of an observation unit (OU) when managed as a closed unit vs an open unit.

Methods: This observational, retrospective study of a 30-bed OU compared three time periods: Nov 2007 to Aug 2008 (period 1), Nov 2008 to Aug 2009 (period 2) and Nov 2010 to Aug 2011 (period 3). The OU was managed and staffed by non-emergency department physicians as an open unit during period 1, and a closed unit by emergency department physicians during periods 2 and 3.