Laboratory risk factors for hospital mortality in acutely admitted patients.
BACKGROUND
Many factors affecting hospital mortality in acutely admitted patients are poorly understood. Although scoring systems exist for critically ill patients, usually in intensive care units (ICUs), there are no specific mortality prediction systems for general acute admissions.


OBJECTIVE
To assess the relationship between simple admission laboratory variables on the risk of in-patient mortality.


METHODS
Retrospective analysis of hospital admissions and laboratory databases.


METHODS
Where possible, all deceased patients in the 12-month period of study were matched with two surviving controls. The laboratory database was then analysed for admission investigations, including serum sodium, plasma glucose, and white blood cell (WCC) count. Abnormalities of these variables were then compared between cases (those who subsequently died), and controls (those who survived).


RESULTS
There were 16 219 admissions, with an overall mortality of 7.6%. We investigated 602 cases and 1073 controls. Hyperglycaemia (glucose >11.0 mmol/l) (OR 2.0, p < 0.0001); severe hyponatraemia (sodium <125 mmol/l) (OR 4.0, p < 0.0001); and leukocytosis (WCC >10 x 10(9)/l) (OR 2.0, p < 0.001) were significantly associated with mortality. The respective associations on logistic regression analysis were: glucose, OR 1.7, p = 0.02; sodium, OR 4.4, p < 0.0001; WCC, OR 1.5, p = 0.006. Low glucose levels, high sodium levels, and low WCC levels were also associated with increased mortality, leading to 'U-shaped' mortality associations. The effect of more than one laboratory abnormality being present was cumulative, in a linear fashion.


CONCLUSIONS
Plasma glucose, serum sodium and WCC are measured in most acutely admitted patients, and abnormalities of these variables have associations with in-hospital mortality. This may provide the basis for the development of a mortality risk scoring system.
Asadollahi
K
K
Liverpool School of Tropical Medicine, Liverpool, UK.
Hastings
I M
IM
Beeching
N J
NJ
Gill
G V
GV
D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose; D016638:Critical Illness / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012964:Sodium / Q000097:blood
D001786:Blood Glucose; D012964:Sodium