Table 5. Drugs-related Death Rates by Follow-up Era and Time Since Hospital-discharge: Adjusted Using Cox Proportional Hazards Regression With Calendar Time as the Underlying Time-scale, SDMD Cohort, Scotland, 1996–2010.

Follow-up era	Apr 1996–Mar 2006		Apr 2006–Mar 2010
	Hazard ratio (95% CI)		Hazard ratio (95% CI)
Age
< = 34 years (referent)
35+ years	1.16	(1.03, 1.31)	1.12	(1.00, 1.27)
Sex
Female	0.54	(0.47, 0.62)	0.58	(0.50, 0.68)
Male (referent)
Injector status
Inject in past month	1.25	(1.10, 1.42)	1.26	(1.09, 1.45)
Ever injected (referent)
Never injected	0.56	(0.48, 0.66)	0.64	(0.54, 0.76)
Unknown	0.62	(0.44, 0.87)	0.61	(0.42, 0.88)
Time since last SDMD registration
<12 weeks	1.34	(1.12, 1.60)	1.64	(1.29, 2.10)
3–12 months	1.09	(0.94, 1.26)	1.24	(1.02, 1.51)
1–2 years (referent)
2–5 years	0.80	(0.69, 0.92)	0.89	(0.75, 1.06)
5+ years	0.44	(0.34, 0.57)	0.61	(0.50, 0.74)
Misuse sedatives
Yes	1.08	(0.97, 1.21)	1.28	(1.13, 1.46)
No (referent)
Misuse stimulants
Yes	0.97	(0.83, 1.13)	1.04	(0.89, 1.22)
No (referent)
Misuse cannabis/tobacco
Yes	0.87	(0.76, 0.98)	0.80	(0.69, 0.93)
No (referent)
Misuse alcohol
Yes	1.48	(1.26, 1.73)	1.45	(1.26, 1.67)
No (baseline)
HCV diagnosis
Yes	1.31	(1.15, 1.50)	1.28	(1.10, 1.48)
No (referent)
Time since last hospitalised
Hospitalised	35.47	(29.01, 43.35)	32.92	(25.33, 42.79)
within 28 days	11.83	(9.87, 14.18)	15.09	(12.12, 18.80)
29–90 days	5.73	(4.71, 6.98)	8.01	(6.36, 10.08)
91 days– 1 year	4.15	(3.56, 4.84)	5.90	(4.91, 7.08)
1+ years	2.44	(2.09, 2.86)	2.88	(2.43, 3.41)
Never admitted (referent)

Abbreviations: SDMD, Scottish Drugs Misuse Database; CI, Confidence Interval