Table 5. Forward stepwise multivariate Cox regression analysis for hazard ratios of mortality in severely PQ-poisoned patients treated with repeated pulse therapy, according to baseline variables and HP <4 h (n = 136).

Potential variable	Multivariate Cox hazard analysis
	Hazard ratio (95% CI)	P
Age (years) (Each increase of 1 year)	1.03 (1.01−1.04)	<0.001
Time elapsed to HP <4 h (Yes)	0.19 (0.05−0.79)	0.022
Initial acute kidney injury (Yes)	2.84 (1.68−4.78)	<0.001

CI: confidence interval; HP: hemoperfusion; PQ: paraquat.