Table 3. Adjusted Hazard Ratios for the Remaining Variables in the Final Model of Multiple Stratified Cox Proportional Hazard ^a.

Variable	Adjusted Hazard Ratio	95%Conf. Interval		P Value
		Upper	Lower
Without history of drug treatment	0.657	1.466	0.294	0.3
Without history of involving in harm reduction programs	0.324	0.736	0.142	0.007
Tattooing	0.453	0.879	0.233	0.01
Duration of addiction, y	0.937	1.00	0.877	0.048
Age of addiction onset, y	0.965	1.02	0.909	0.2
Imprisonment for drug trafficking	1.266	2.709	0.591	0.5

^a Stratified by Prisons.