The aim of this study was to assess the change in workload in a general sur
gery department over 2 consecutive 1-year periods and document the impact o
f a high dependency unit (HDU) on hospital mortality. Data were collected o
n all admissions, the number and type of operations performed for a 1-year
period before and after a purpose-built HDU was opened. During the study pe
riod, the total number of admissions increased by 15%, with a disproportion
ately large increase (27%) in the number of emergency admissions. This was
reflected by increases in the emergency out-of-hours operating by 12%, Duri
ng the study period, the overall in-patient mortality rose from 2.16% to 3.
2%.
Introduction of HDU facilities alone does not lead to a reduction in hospit
al mortality. Alterations in emergency workload and changes in case-mix are
important in determining outcome. League tables of hospital mortality are
likely to be difficult to interpret without adequate information about faci
lities and case-mix.