Impact of an acute medical admission unit on hospital mortality: a 5-year prospective study

Abstract

Aim: To determine the impact of the introduction of an acute medical admission unit (AMAU) on all-cause hospital mortality in unselected patients undergoing acute medical admission to a teaching hospital.

Design: Analysis of data recorded in the hospital in-patient enquiry (HIPE) system relating to all emergency medical patients admitted to St James's Hospital (SJH), Dublin between 1 January 2002 and 31 December 2006.

Methods: The reference year was 2002, during which patients were admitted to a variety of wards under the care of a named consultant physician. In 2003, two centrally located wards were re-configured to function as an AMAU, and all emergency medical patients were admitted to this unit following emergency department evaluation. Hospital mortality was obtained from a database of deaths occurring during this period and linked to HIPE data.

Results: Following the introduction of the AMAU process, all-cause hospital mortality decreased from 12.6% in 2002 to 7.0% in 2006 (P < 0.0001), representing a 44.4% relative reduction during the course of the 5-year observation period (P < 0.0001). The Odds ratio (95% confidence interval) for all-cause mortality in 2006 compared with 2002 was 0.28 (0.23, 0.35). This effect was powerfully independent of other covariates, including Charlson co-morbidity and illness severity score (APACHE II), in binary logistic regression analysis and was observed across a wide cross-section of diagnostic groups.

Conclusion: The introduction of an AMAU significantly improved all-cause hospital mortality in acute unselected medical patients. The delivery of Acute Medicine may be enhanced by structural reform with emphasis on focus and volume. Prospective studies validating similar models elsewhere should be explored.