Benzodiazepine prescription for patients in treatment for drug use disorders: a nationwide cohort study in Denmark, 2000–2010

Table 5 Relative risk ratio (RRR) from multinomial logistic regression of having a continued prescription of benzodiazepines according to different factors

	Prescription of benzodiazepines 1 year after admission in moderate-high doses <584 DDD^a			Prescription of benzodiazepines 1 year after admission in very high doses ≥584 DDD^a
	Unadjusted RRR	Adjusted^b RRR (95 % CI)	p value	Unadjusted RRR	Adjusted^b RRR (95 % CI)	p value
Female	1.1	1.0 (0.9-1.2)	0.310	1.2	1.0 (0.9-1.2)	0.639
Age group at admission date
18 – 27 years	1.0 (referent)	1.0 (referent)		1.0 (referent)	1.0 (referent)
28 – 37 years	1.8	1.7 (1.4-1.9)	<0.001	3.8	2.8 (2.3-3.5)	<0.001
38 – 47 years	2.4	2.1 (1.8-2.4)	<0.001	7.6	4.9 (4.0-6.1)	<0.001
48 – 67 years	3.7	3.3 (2.7-3.9)	<0.001	13.3	7.8 (6.2-9.9)	<0.001
Primary drug use at admission
Cannabis	1.0 (referent)	1.0 (referent)		1.0 (referent)	1.0 (referent)
Methadone or buprenorphine	2.4	1.8 (1.5-2.2)	<0.001	15.2	8.3 (6.2-11.1)	<0.001
Heroin	1.5	1.3 (1.1-1.6)	0.001	5.1	3.6 (2.7-4.8)	<0.001
Other opioids	2.0	1.5 (1.1-2.1)	0.005	9.1	5.2 (3.6-7.7)	<0.001
Benzodiazepines	2.5	2.1 (1.5-2.8)	<0.001	9.4	6.9 (4.5-10.6)	<0.001
Central stimulating drugs^c	0.9	0.9 (0.7-1.1)	0.431	1.1	1.1 (0.7-1.7)	0.633
Other illicit drugs/unknown	1.7	1.4 (1.2-1.6)	<0.001	7.6	4.6 (3.5-6.0)	<0.001
Psychiatric treatment received in 1 year prior to admission^d	1.0	1.2 (1.0-1.3)	0.006	0.6	0.6 (0.5-0.7)	<0.001

Group of previous users without prescription of benzodiazepines, n = 2464; group of previous users with prescription of benzodiazepines in moderate-high doses, n = 4113; group of previous users with prescription of benzodiazepines in very high doses, n = 2026.
Abbreviations: DDD, Defined Daily Dose; CI, confidence interval.
^aIntake of 1 DDD daily of benzodiazepines in a 1 year period results in a total intake of 365 DDD.
^bAdjusted for gender, age group at admission date, primary drug use at admission, and psychiatric treatment received in 1 year prior to admission.
^cAmphetamine, cocaine, and MDMA.
^dInformation obtained from the Danish Psychiatric Central Research Register.

ISSN: 1471-244X