Article Document Academic Article Information Content Entity Continuant Continuant Journal Article Entity Entity Generically Dependent Continuant 2025-05-06T12:48:59 RDF description of Advanced statistics: developing a formal model of emergency department census and defining operational efficiency - http://repository.healthpartners.com/individual/document-rn18779 Academic Emergency Medicine Models 19960 <p>BACKGROUND: Emergency department (ED) crowding has been a frequent topic of investigation, but it is a concept without an objective definition. This has limited the scope of research and progress toward the development of consistent and meaningful operational responses. OBJECTIVES: To develop a straightforward model of ED census that incorporates concepts of ED crowding, daily patient surge, throughput time, and operational efficiency. METHODS: Using 2005-2006 patient encounter data at a Level 1 urban trauma center, a set of three stylized facts describing daily patterns of ED census was observed. These facts guided the development of a formal, mathematical model of ED census. Using this model, a metric of ED operational efficiency and a forecast of ED census were developed. RESULTS: The three stylized facts of daily ED census were 1) ED census is cyclical, 2) ED census exhibits an input-output relationship, and 3) unexpected shocks have long-lasting effects. These were represented by a three-equation system. This system was solved for the following expression, Census(t) = A(.) + B(.) cos(vT + epsilon) + a(e(t)), that captured the time path of ED census. Using nonlinear estimation, the parameters of this expression were estimated and a forecasting tool was developed. CONCLUSIONS: The basic pattern of ED census can be represented by a straightforward expression. This expression can be quickly adapted to a variety of inquiries regarding ED crowding, daily surge, and operational efficiency.<p> 9 public 10.1197/j.aem.2007.05.011 2022-02-21T22:48:57.408-06:00 14 Crowding document-rn18779 Hospitalization Organizational Innovation Emergency Medicine Management 12690 Advanced statistics: developing a formal model of emergency department census and defining operational efficiency