Multivariate analysis of the predictors for in-hospital mortality by fitting multiple Cox proportional hazards model with the stepwise variable selection method.

Notes: Variables put into multivariate analysis were selected if they had a P≦0.1 on univariate analysis or if they are thought to be important. They included age, DM, cirrhosis, heart failure, CKD, ECMO, mechanical ventilation, initial neurological dysfunction, sepsis and some parameters (RIFLE-I & F, MAP, IE, APACHE II scores) at RRT initiation, early and late group as compared with intermediate group, indications for RRT (including azotemia, fluid overload & oliguria, and hyperkalemia & acidosis), as well as surgery types (including neurosurgery, chest surgery, CVS, abdominal surgery, and other surgery). Duration for analysis is measured using calendar days from RRT initiation to end point (mortality or discharge).

a

hazard for patients in intermediate group  =  1.0;

b

every increment of 1 year or point;

c

hazard for woman  =  1.0; hazard for patients without DM. ^c, liver cirrhosis.

d

ECMO.

e

initial neurological dysfunction.

f

sepsis at RRT initiation.

g

 = 1.0.

h

data measured at RRT initiation.

Abbreviations: APACHE-II, Acute Physiology and Chronic Health Evaluation II; CI, confidence interval; CKD, chronic kidney disease; DM, diabetes mellitus; ECMO, extracorporeal membrane oxygenation; IE, Inotropic equivalent; MAP, mean arterial pressure; RRT, renal replacement therapy.