Table 3. Forward stepwise multivariate Cox regression analysis for hazard ratios of all-cause mortality in severely PQ-poisoned patients, according to baseline variables and HP <5 h (n = 207).

Potential variable	Multivariate Cox hazard analysis
	Hazard ratio (95% CI)	P
Age (years) (Each increase of 1 year)	1.02 (1.01−1.03)	<0.001
PQ(U)-navy blue color (Yes)	0.15 (0.05−0.40)	<0.001
Time elapsed to HP <5 h (Yes)	0.60 (0.39−0.92)	0.019
Initial acute kidney injury (Yes)	2.62 (1.77−3.89)	<0.001
Repeated pulse therapy (Yes)	0.57 (0.40−0.82)	0.002

CI: confidence interval; HP: hemoperfusion; PQ: paraquat; PQ(U): urine paraquat.