Table 5.

Significant predictors for the time to next hospitalization (Cox proportional hazard regression analysis)*

Covariate	b	SE	Wald	P	Exp(b)	95% CI of Exp(b)
Paco2 on admission day	0.031	0.015	4.099	0.042	1.031	1.001 to 1.062
pH on a second day	-11.090	3.988	7.735	0.005	0.000	6.15*10−9 to 0.038
Fibrinogen	-0.519	0.162	10.294	0.001	0.595	0.433 to 0.817
Total serum protein	-0.134	0.043	9.921	0.002	0.874	0.804 to 0.951
Alfa2 globulin	0.554	0.210	6.923	0.009	1.739	1.152 to 2.627

*Abbreviations: SE – standard error, CI – confidence interval.